Air conditioner not cooling – outdoor unit not running

Jul 26, 14 • DIY Tips, News520 Comments

It is a big deal when the air conditioning goes out on a hot summer day, but there is no need to wait for help to come to you.  Many air conditioning malfunctions are not difficult to identify and repair.  The following test procedure will help you identify if the problem with your outdoor unit is the fan motor, the capacitor, or the contactor.

Condenser-Fan-Motor

Troubleshooting the “outdoor air conditioner unit not running” starts with some easy commonsense steps:

  1. Make certain the thermostat is set to cool and the indoor unit is running (blowing air out the room air vents).
  2. Listen to the outdoor unit for the sound of the compressor running.
  3. If you hear the compressor running go to “section A” below. Note, compressors can run quietly.
  4. If you cannot hear the compressor running go to “section B” below.

Section A; you can hear the a/c compressor running and the fan motor is not turning.

Because the compressor is running you know there is 220 volts power to the outdoor unit and you know the contactor is doing its job of delivering that 220 volts to the compressor and to the motor.  The malfunction will be a bad capacitor and/or a bad motor. Capacitors can be tested with multi-meters that have the ability to read microfarads or you can take your capacitor (and your motor) to your nearest U-FIX-IT store for a free bench test.  If the capacitor tests good then your motor is bad.

Caution – Capacitors can store an electric charge (like a battery).  The shock hazard is non-lethal, but it is no fun.   Check the 220 volt power is off and discharge the capacitor by shorting between capacitor terminals (with insulated screwdriver) before removing the wires from the terminals.

Interesting facts

  1. A capacitor connected to both the compressor and the motor can fail on just the motor side.
  2. Bad a/c fan motors can sometimes be started by “spinning” the fan blade with a stick – it is still a bad motor.

Purchase a New AC Motor

Contactor

Section B; you cannot hear the a/c compressor running and the fan motor is not turning.  Your next troubleshooting step will be checking the 220 volt power because it is highly unlikely both the compressor and the fan motor would fail at the same time.  Failure of the contactor (see picture above) most often produces this symptom.  You can prove the contactor is the problem by using a multi-meter or you can take your contactor to your nearest U-FIX-IT store for a free bench test.

Testing the contactor on air conditioner outdoor unit

  1. Using a multi-meter, verify there is 220 volts going into the contactor, but zero volts coming out of the contactor (to the motor and compressor). If you  you have 220 volts coming out (contactor is good) then check the capacitor or bring it in to U-FIX-IT for a free bench check.
  2. Check for 24 volts across the coil terminals. If no 24 volts call U-FIX-IT for assistance.
  3. Contactor is bad if multi-meter reads 220 volts going in, zero volts coming out, and 24 volts across the coil terminals.

Contactor voltage check top view 

Caution: use care when measuring live voltages not to touch bare connections or short them to the cabinet or to other terminals with the meter probes.

Purchase a New AC Contactor

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More From Jim Plummer

Jim is an ex-Air Force pilot and a business school graduate of University of Texas at Austin. He has been in the appliance parts business since 1975.

520 Responses to “Air conditioner not cooling – outdoor unit not running”

  1. Jeremy Johnson says:

    Hi Jim

    To add my voice to the chorus, thankyou so much for offering your wisdom to those of us who are not experts in aircon – it’s very much appreciated!

    OK, so here is a real puzzle for you: I have a pair of split reverse-cycle aircon units in my apartment in Australia, and one of them is behaving really strangely. They are both Heller ACK25RC (2.5kw cooling, 2.7kw heating, 5.3A 1.2 kw power-draw) units, and were installed 2008, The external comressor units are less than 2 metres from the internal units, which are mounted on the outside of the same wall than the internal units are bolted to.

    If I start the malfunctioning unit after an overnight rest, and set a low temperature, then all seems well – compressor light shows ON, and the unit cools air to 14 deg within 4 minutes, and maintains this, apparently indefinitely (at least for > 30 mins). The fan exhaust from the external compressor unit is approx 10 degrees warmer than ambient.
    If the temp is then set to a temp at which the compressor-light is turned OFF buy the controller, the temp, rises to meet the new set-temp over a few mins as expected.
    If the set temp is subsequently reduced to a level that requires the compressor to be ON, then although the compressor light shows ON and the compressor appears to be active, it fails to achieve any cooling. The air is warm, and the input/output valves of the compressor unit are ambient temp, and the fan exhaust is also at ambient-air temperature.

    some basic checks first:
    Checked remote – mode set to cooling, set temp=18 deg.
    checked filters – clean.
    Checked fan – spinning OK when compressor is active (ie when compressor light on internal unit is on)
    Checked pipes: when fault is present, Very weak cooling at refrigerant output pipe to head unit.

    Hmmm… some more advanced diagnostics are clearly required, so I opened up case (NB I am well-qualified to do this, so no concerns there) :
    Checked capacitor – no damage or swelling. Disconnected, it measures at 43.05 microfarad, within 5% of it’s 45 microfarad rating.
    Checked separate fan-motor capacitor – Disconnected, it measures at 1.05 microfarad , about 70% of it’s rated 1.5 microfarad
    Checked fan motor operation – runs fine
    Checked resistance of compressor-motor coils : (start=black, run=red common=white)
    start:run =8.9 ohms, run:common = 4.0 ohms; start:common= 5.2 ohms. Seems consistent with a working unit, as far as I can tell.
    Compressor seems to make slight chuffing noise when running – no rattles or bangs.
    Compressor body (inside case) is hot to touch after 10 mins running.
    There are no obvious signs of R22 working-fluid leaks anywhere that I can see anywhere

    So, in summary, I appear to have a split-unit that will run completely normally only ONCE per approx-24hrs in cooling-mode – but not twice – but that does not show any obvious faults, beyond the slightly-weak fan-motor capacitor.

    I’m stuck for what to try next. Any ideas?

    • Jim Plummer says:

      Jeremy,

      Intermittent symptoms are the most difficult to troubleshoot. You have the advantage of being able to produce the malfunction on demand. There may be a simple solution, but I will be unable to guide you to it via email. There are times when it makes sense to pay the price for an expert troubleshooter to come to you and find the problem. I would say you are at one of those times. You have done an exceptional job of recording symptoms and readings. Share your work with the technicians you interview over the phone. I suspect most will either say something that causes you to eliminate them or they will make an excuse as to why they are too busy, but there will be a technician who is confident in his skill and ability who will come to your aid. It is unlikely he will be the lowest price and he most likely cannot come right away(the best technicians stay busy), but he will solve the mystery. Thank you for your inquiry.

      Jim

  2. Ty says:

    Dear Jim,

    Reside in Florida and have a Lennox AC which is not working right. It does not power on and the fan those not rotate. Tried using a stick to rotate the fan, but it wont rotate, no humming sound coming from the system either. However, if I push the contactor button, the fan works and ac blows, but will stop and wont stick/energize if I release the contactor. I have 240 coming in and out but no 24 across the coils.

    Please advise

    Ty

    • Jim Plummer says:

      Ty,

      24 volts at the coil is absolutely necessary for the contactor do its work. If the indoor unit is coming on, I would look for a break in the low voltage wire (thermostat wire) running between the furnace and the outdoor unit.

      Call the nearest U-FIX-IT store for personalized free troubleshooting assistance.

      Jim

  3. Frank says:

    Hi Jim
    My ac fan motor and compressor runs only when i go outside and hit it, I replaced the contactor and the capacitor, I took the fan motor to a place to test it and it was good, what do you think the problem can be?
    thanks

    • Jim Plummer says:

      Frank,

      I am not certain what you mean by “hitting it.” If that means you are spinning the fan blade to start the motor, then I would replace the motor. Otherwise, I need to know specifically what you are hitting.

      Jim

  4. Charles says:

    Hey Jim
    So my a/c went out sometime last night, things that I did was went outside and notice my fan was not working, I flip the breaker and it would last about 5 second and turned off but fan was still not moving, did flip again and i spinned the fan and it started to move and then turned off, I unscrewed the cover and found one of the wires on the capitors was fried so I re did the connection flip the switch, and started to hear it humm. Moved the fan with a long screw driver and fan is now spinning, went inside but still no cold air coming out of the vents

    • Jim Plummer says:

      Charles,
      You can take the motor and capacitor to the nearest U-FIX-IT store for free testing. Your symptom is the classic symptom of a failing motor. If it was mine, I would replace the fan motor and the capacitor. It is important to replace any burned wiring with a wire of sufficient size. Make sure all connections and connectors are tight and secure.
      Jim

  5. Kyle Barker says:

    Hello –

    The AC fan stopped running this morning. I went out and checked the fan blade and it is not frozen. Also I cannot hear any humming at the outdoor unit when I turn it on at the thermostat inside. Air comes out of the registers but it is not cold. Based on your web site I am thinking power is not getting to the AC unit…
    Thanks for your help/thoughts.

    • Jim Plummer says:

      Kyle,

      I agree, your symptoms point to no power reaching the compressor and fan motor. The most common failure to produce that symptom is a bad contactor.

      To verify, I would use a multi-meter to verify 220 volts coming to the unit from the house. If 220 volts is present then I would check for 24 volts (control voltage from the thermostat indoors) at the contactor. If 24 volts is present and 220 volts is not present on both sides of the contactor (incoming from the house and outgoing to the compressor & fan motor) then the contactor is bad.

      Alternatively, you can turn off the power to both the indoor unit and the outdoor unit. Take a picture of the wire connections on the contactor. Remove the contactor and take it to the nearest U-FIX-IT store for free testing. You can also call from free personalized assistance with your troubleshooting.

      Jim

  6. Andrew says:

    No air – cold or warm – is coming from the vents when i turn my AC on. The fan on top of the ac unit outside runs, but no AC from the inside vents. Tried switching the capacitor and contactor from my working AC unit, but same result. I also checked/reset the breakers. Any thoughts/suggestions MUCH appreciated.

    • Jim Plummer says:

      Andrew,

      As I understand your symptoms, your system is not moving any air inside the house.

      If the indoor fan motor is running, visually check filter and the indoor coil. Change the filter if it is dirty and clean the indoor coil if it is dirty. If the indoor coil is iced up, then defrost the coil and clean the indoor coil and the outdoor coil.

      If the indoor fan motor is not running, look for a wiring diagram usually located on the inside of one of the door panels on the indoor unit. Use the wiring diagram and a multi meter to locate the component that is preventing the power from reaching the motor. If you have 110 volts (220 volts for electric furnace) going to the motor and the motor is not running, then the motor or the capacitor is bad. You can take the motor and the capacitor to the nearest U-FIX-IT store for free testing or call for free assistance in the troubleshooting process.

      Jim

  7. J W says:

    Please help
    My central air Outside Fan didn’t work so I turned the fan manually it it started to work.
    But it doesn’t cool it doesn’t give out Warm air as it supposed to do.
    What can be done to fix it.
    Thanks

    • Jim Plummer says:

      JW,

      I always repair the obvious malfunction first and then troubleshoot again. A fan motor that will run after turning the fan manually is a motor that I would replace if it was on my ac unit. I always replace the capacitor whenever I replace the motor.

      It is hard on the compressor to continue to run it after the motor shuts off. The compressor temperature will rise until it’s internal safety thermostat shuts it down. That may be the reason your house was still warm after manually starting the fan. Also, your bad motor may not be turning at full speed after the manual restart, which in turn reduces the cooling capacity.

      After the motor and capacitor are replaced I would reassess and start the troubleshooting process from the beginning. It is likely your cooling will return to normal with no further action needed.

      Jim

  8. Steve says:

    Hi Jim,

    Great information! Yesterday the blower in my house was working, but the air wasn’t cool and the house wasn’t dropping in temperature. I went out to look at the condenser unit and the fan wasn’t spinning at all. Today I saw your website and using your advice decided to find out if I could hear if the condenser unit was on. Now everything is working properly. Wife told me this happened a few days ago when the AC was on also, so it appears to be an intermittent problem.

    Can you advise?

    Thanks very much!

    Steve

    • Jim Plummer says:

      Steve,

      An increase in outdoor air temperature can cause the fan motor to stop running. Motors have an internal thermostat that cuts power to the motor when they get too hot. Motors run hotter as they age and they have no problem on cooler days. A hot day can push the motor operating temperature up to the point the internal safety thermostat cuts the power. It is hard on the compressor to continue to run it after the motor shuts off. The compressor temperature will rise until it’s internal safety thermostat shuts it down. I would replace the fan motor and capacitor if it was my ac unit.

      Jim

  9. Joe Glyshaw says:

    I have an old Rheem condenser. I had to replace the capacitor last year. The fan ended up going bad due to age. I bought a new motor fan and tested capacitor. I installed fan motor but it has 5 wires protech 51-23055-11, yellow, black, orange, brown, purple. I followed instructions. Black to contactor, yellow and brown to capacitor, purple/orange attaches together to contactor. The fan won’t start. What do I do?

    • Jim Plummer says:

      Joe,

      I always replace the capacitor when I replace the fan motor. A bad motor can ruin a capacitor and a bad capacitor can ruin a motor. Make certain the capacitor you are using is a match for your new motor. The capacitor size it needs will be printed on the side of the motor. From your description it appears you may have a 2 speed motor. If that is the case only one of the speed wires would connect directly to the contactor (either the low or the high speed, but not both). Connecting motor wires incorrectly can cause a new motor to burn the windings, ruining the motor. I hope that is not the case for you. You can call the U-FIX-IT store closest to you for free personalized help in trouble shooting your installation.

      Jim

  10. Vanessa O'Neal says:

    Hello! I have a Lennox unit in my home (about 7-8 years old). The indoor system kicks on, but is not blowing out any cold air. The outdoor AC unit will not turn on at all. I tried resetting the fuses on the breaker box and it still will not turn on. Any idea what this could potentially be?

    Thanks!

    • Jim Plummer says:

      Vanessa,

      One of the most common items to cause an outdoor AC unit(both the fan motor & the compressor) to not come on is a bad contactor. If you have a multi-meter you can use the procedure below to confirm it is a bad contactor, or you can disconnect the power from both the indoor unit and the outdoor unit, remove the contactor and take it to the nearest U-FIX-IT store for free testing. U-FIX-IT will also be happy to give you personalized help over the phone in troubleshooting your unit.

      Testing procedure I would use to test a contactor.

      Using a multi-meter, verify there is 220 volts going into the contactor, but zero volts coming out of the contactor (to the motor and compressor). If you you have 220 volts coming out (contactor is good) then check the capacitor or bring it in to U-FIX-IT for a free bench check.

      Check for 24 volts across the coil terminals. If no 24 volts call U-FIX-IT for assistance.

      Contactor is bad if multi-meter reads 220 volts going in, zero volts coming out, and 24 volts across the coil terminals.

      If this is not helpful, please call your nearest U-FIX-IT store for free troubleshooting assistance.

      Jim

  11. brandon flynn says:

    Trane heat pump. The fan will try to start and will hum but the the fan does not spin. attempted to start the fan with a manual push but it did not work and there was resistance to the push. the fan will continue to hum and then get very hot. I have not heard the compressor turn on either. the start capacitor was replaced a year ago.

    • Jim Plummer says:

      Brandon,

      I would start troubleshooting by using a multi-meter to check that there is 220 volts arriving at the outdoor unit and going to the motor. If 220 volts is present going to the motor then either the motor or the capacitor is bad. If 220 volts is arriving at the unit and not present going to the motor, then I would use the wiring schematic to test the components in the circuit between the two test points. You can call the nearest U-FIX-IT store for personalized help trouble shooting your unit, or you can take the motor, capacitor, and contactor to the nearest U-FIX-IT store for free testing. U-FIX-IT Appliance Parts is closed until Tuesday for Memorial Day to honor our veterans.

      Jim

  12. Chuck W. says:

    Hi Jim,

    My AC unit is not cooling my house. I can feel some cool air coming from the vents (weakly) but it will not drop the temperature inside the house. The fan is turning and it seems to be running but about every minute the unit makes a surging sound like it is trying to start something but then cuts immediately off…then tries again a minute later with the same results. Any idea what would be causing this?

    • Jim Plummer says:

      Chuck W.

      Sounds like you are saying that your outdoor fan motor is running and you are hearing a surging sound in the outdoor unit that sounds like something is attempting to start. If this was my a/c unit I would start by measuring the capacitance of the large capacitor located in the outdoor unit. You can take the capacitor to the nearest U-FIX-IT Store for free testing.

      For personalized free help in troubleshooting your a/c call the nearest U-FIX-IT store.

      Jim

  13. John Plummer says:

    Hi Jim

    You are popular but I’m not surprised being a Plummer!

    My AEG R/V A/C cooling won’t work after power blackout.

    Not sure if the A/C caused the blackout or something else which caused this problem!

    I’ve turned the power to the unit off for 30 minutes but alas to no avail…

    Next step?

    Thank you for any help

    John Plummer (Oz)

    • Jim Plummer says:

      John,

      I am not familiar with your cooling unit, but if it was my unit my first step would be to locate the wiring diagram. After making certain the necessary voltage is present at the unit, I would look for a fuse or breaker in the circuit. If those are good, then I would work my way through the circuit until I locate the bad component.

      Call the nearest U-FIX-IT store for additional help.

      Jim

  14. Mohsen says:

    Jim,

    My AC in the “Heat” mode works without any problem. The outside unit runs well (fan and compressor) and inside unit blow warm air as expected. However, as soon as I change it to “Cool” mode with the right temperature (i.e, selecting a temperature below the current room temperature), the outside unit stop working and the inside unit just blows air (no cooling). What may be the problem and how it can be fixed.

    Many thanks,
    Mohsen

    • Jim Plummer says:

      Mohsen,

      No obvious, easy fix here. Since the outdoor unit is working in the heat mode, I would suspect the 24 volt control voltage is not getting to the outdoor unit. Locate the wiring diagram on the indoor unit and use it to help you trace the circuit with a multi-meter to find where you are losing the 24 volts.

      Jim

  15. Daniel says:

    My Samsung AC is not cooling properly.

    Changing the temperature does not make any difference.

    It only works when I try to switch it to “Turbo Mode” via the remote in which this will automatically turns off in about 15 to 20 minutes of cooling time. After that, I need to switch it again to “Turbo Mode”.

    Any ideas what’s the cooling issue?

    Thanks.

  16. angelo says:

    i have a split type a/c not cooling inside the house..i check the condenser fan and it is not working but when i turn it manual it started running. i changed the fan capacitor and it started running for one day, but the other night it fail again..do you think i need to replace the condenser fan?

    can i use insulation test for the fan motor if it is already damage or what test can i make.

    thanks

    • Jim Plummer says:

      Angelo,

      If the capacitor matches the motor and you have 220 volts going to the motor when it is not running, then it is a bad motor. Be sure to replace the capacitor again if you decide to replace the motor. I never reuse a capacitor that has been hooked up to a bad motor even it is for a very short time.

      Jim

  17. Dan says:

    Hi, I came home to my upstairs unit blow warm air. I checked the outside, the fan was not turning, I can start it on with a stick but still blowing warm air inside so I turned it off. Would this be the capacitor?

    • Jim Plummer says:

      Dan,

      This is a classic symptom of a bad motor. I would replace both the motor and the capacitor if it was mine. You can take the capacitor to the nearest U-FIX-IT store for free testing and a new capacitor may buy you a little more time.

      Jim

  18. Jennifer says:

    I have warm air blowing inside when my unit is on, but outside at the unit I hear humming and the fan is not turning. What could this mean?

    • Jim Plummer says:

      Jennifer,

      The fan motor should be running whenever the compressor is running. The power to the outdoor unit should be cutoff until the fan motor is running again to avoid permanent damage to the compressor. You can take the fan motor and capacitor to the nearest U-FIX-IT for free testing.

      Jim

  19. Liam says:

    Thanks for posting this. I woke yesterday to my upstairs being hot. When I checked the unit outside the fan was not moving. Bought new motor and had to buy new capacitor since it was not an exact match. The existing capacitor was dual round, so I left it alone and ran new motor wires to new capacitor. Turned everything on and fan works but compressor just hummed. I looked at wiring of compressor to the existing dual round and it looked wrong. Nothing was going to COM, wire from compressor was connected to FAN, and wire from contactor was going to HERM. This is how it was wired originally. I did not change any of this wiring, just disconnected the old fan from the dual round. I realized this was wrong and became very confused as how this setup worked for the past 6 years. I moved wire from compressor to HERM on the capacitor and the wire from contactor to COM. I now hear the compressor on, but air blowing out of outside unit is cold and air inside home is not blowing cold. Do you think I just need a new capacitor for the compressor even though it sounds like it is running? Is it possible my compressor is not functioning correctly from the incorrect wiring or overheated when fan stopped working?

    • Jim Plummer says:

      Liam,

      Most outdoor units have a wiring diagram on one of the panels. I would use that to confirm all of the wiring connections. It appears you have done the new motor and new capacitor wiring correctly. If your outdoor unit is a heat pump then a miss wire or disconnected wire could cause the reversing valve to be in the heat position instead of the cool position. If your outdoor unit is not a heat pump then you may have a bad compressor. It may be a good time to get a second opinion from an a/c technician.

      Jim

  20. Orion says:

    Jim,

    My AC is blowing plenty of air through the vents, but it is not cooling. At the outside unit the fan is spinning, but I’m not hearing the compressor. I took the panel off, and an orange wire that wemt from the capacitor to the compressor had been burned off of it’s connection terminal. As it’s Sunday, I couldn’t find a place to buy a new capacitor. I cut off the damaged portion of the wire and put a new female terminal on, then reconnected it to the capacitor. I fired the system back up and the fan ran again, but not the compressor. The fan stopped and started a few times, then it kicked on again. After about 5 minutes the compressor kicked on too. The unit started blowing hot air, then the fan stopped while the compressor continued to run. Inside I had cool air. Now the compressor has stopped running and I’m not getting anymore cooling, but the outside fan is still spinning. Any thoughts?

    • Jim Plummer says:

      Orion,

      You symptoms are pointing toward a bad motor. Old motors run hotter than young motors and a hot day will cause them to cut out on the internal safety. When the fan motor quits running it is a matter of time until the compressor cuts out on it’s internal safety. Both the motor and the compressor safeties will reset when they cool off and they will restart. Never continue to run the compressor without the fan motor running. If it was my unit I would start with replacing the fan motor and capacitor.

      Jim

      • Orion says:

        Jim,

        Thanks for the response. After driving all over God’s green earth I finally found a place willing to sell me a capacitor. While I was connecting it I found a wire the must have been blown off and fallen behind the connector. I traced the one line diagram (should have done that in the first place) and found where it was supposed to connect on the new cap and hooked it up. she’s running like a dream, and my house is cool again. Thanks for the help!

  21. Lacie says:

    Our outside unit works fine. My fiance changed a couple of parts inside because of past issues. We have also had a ac man out before. We seem to have the same issues on and off. Today it wouldnt blow for about 12 hours. Finally i just turned the fan on, i left it on for about 2 hours. I noticed it stated blowing so i went and turned the ac on. Bam, it worked. What could be causing this??

    • Jim Plummer says:

      Lacie,

      Check the voltage present at the motor When your fan motor fails to run. If the correct voltage is present and the capacitor test good, I would replace the motor. If the correct voltage is not present, use the wiring diagram to look for the component that is blocking the voltage. Call your nearest U-FIX-IT store for free personalized assistance.

      Jim

  22. Jennifer Khoshbin says:

    Our fan stopped working. We can hear a hum at the unit. We replaced the capacitor and the motor. A week later the fan stopped working again. Any thoughts?

    • Jim Plummer says:

      Jennifer,

      I would recheck that motor is the correct one for the unit and that the new capacitor is correct for the motor that is installed. In addition I would make certain the motor is turning the correct direction and the fan blade is positioned on the motor shaft so that it is in the correct position in the fan shroud.

      It is unusual for a new motor to fail, hence my attention to scrutinizing the repair. If there is a mistake made in matching the motor or in the installation a second replacement will fail also. If the motor replaced was not the original motor, then the new motor specificiations should be checked against the manufacturers specifications for the motor (unit).

      Call the nearest U-FIX-IT store for free personalized assistance.

      Jim

  23. Matt Parker says:

    Came home to the AC fan not spinning. The AC unit is on the edge of my neighbor’s lawn. He mowed his grass and slung grass debris on the unit. Could this have caused the fan to stop spinning? I tried to clean it off but the blade still wont spin.

    • Jim Plummer says:

      Matt,

      Impossible for me to know if the grass is the cause. A dirty coil can restrict air flow and cause the motor to overheat and shut off. An overheated motor will restart and run after it cools down. An old motor is more vulnerable to overheating than a new one, especially on a hot day.

      If the motor shaft is frozen, then it is a bad motor that most likely died of natural causes.

      Jim

  24. Donnie says:

    Hello Jim,

    First off, thank you so much for being a reliable and trustworthy resource for the public to tap into for help. It’s really cool that you are willing to do this.

    Ok, so to my problem… I have separate units for upstairs and downstairs and I just went downstairs and realized it was way warmer than it should be. Checked the thermostat which was set at 75 but it was 84 in the house. There was air coming from the vents but it was room temp air. I went and checked the unit outside of the house and the fan was not running but there was like a hum/buzz of electricity as if it was powered but not working. And the coolant line running from the unit to the inside was warm, not cold like it should be. I did change the filter because it was very dirty, and I also flipped the breakers but still no luck. Any help would be greatly appreciated.

    Thanks so much,
    Donnie

    • Jim Plummer says:

      Donnie,

      The system will not start cooling as long as the fan motor is not running. If there is 220 volts going to the motor and the capacitor checks good then it is time to replace the motor and capacitor.

      Jim

  25. Jamie says:

    My central air is blowing air but it’s not cold. I checked outside and the unit fan isn’t spinning and doesn’t even make
    A sound like its even on.
    What should
    I do

    • Jim Plummer says:

      Jamie,

      I would first make certain the outdoor unit is getting 220 volt power.

      If it is, I would then shut off the power to both the indoor unit and the outdoor unit, take pictures of the wiring connections on the transformer and the capacitor. Remove the transformer and capacitor and take them to the nearest U-FIX-IT for free testing.

      Jim

  26. Mary says:

    We just had a voltage absorption system blow out because of it overheating from being dirty. It was $550.00 to replace. He said we might need a compressor or hard start kit if the compressor fails. Any idea if that would be possible for us to do ourselves if needed? That would be an additional $334.00 for the tech to do. The ac unit is a Goodman.

  27. Debbie says:

    Woke up to a very hot trailer .. Realised the indoor unit isn’t running then checked outside and same thing.. NOTHING! not even any type of sound coming from either one.. I have checked all the breakers inside and out but all ore on .. I flipped them off and back on anyway. The thermostat seems to be working fine and will click but NOTHING happens.. It is like there is no electricity running to it…. what happened????

    • Jim Plummer says:

      Debbie,
      Most common malfunction when nothing is running is the 24 volt transformer located on the furnace. You can take the transformer to your nearest U-FIX-IT store for free testing.

      Jim

  28. Esmaeil says:

    Hi
    I have two Air conditioners both new, as follows:
    1st AC= Midea brand, 1 ton, R22
    2nd AC=TCL brand, 1 ton, R410a
    Can I use indoor unit of TCL with Outdoor unit of Midea?
    Best Regards,
    Esmaeil

    • Jim Plummer says:

      Esmaeil,

      Matching the outdoor unit to the indoor coil is absolutely critical. A mistake can result in the destruction of the compressor.
      If this was my system, I would not match these two together in the same system. For best long term results make certain the indoor coil is a factory approved match with your outdoor unit.

      Jim

  29. Boyce Smith says:

    Thanks so much for all your great help and advice! I have a similar problem to many. The air handler runs inside but the outside unit is not running. I replace the contactor and it kicked right off and ran great for about 3 days. Next I replaced the capacitor and once again it ran for about 3 days. Cools like crazy when it’s working. The fan spins freely and I have 220 at the unit. I can’t figure this out but it seems like something simple. When it SHOULD be running there is no sound at all at the unit. No compressor hum, no fan trying to start, just silent like the power is off. Any ideas?

    • Jim Plummer says:

      Boyce,
      I would use a multi-meter to measure the voltage at the contactor. There should be 220 volts coming to the contactor and 24 volts coming to the coil on the contactor. When the unit is not running, I would use the wiring diagrams on the furnace and the outdoor unit to chase the missing voltage (either 220 volts or 24 volts) back to the component that is blocking the electricity.

      Jim

  30. Brian says:

    Jim,

    I had my AC system put in about 8 years ago by an HVAC person, it was done off the books.
    Everything was working normally until recently, a technican told me that lightning could have been the cause. I had a reputable company give me an estimate and said the entire unit needs to be replaced, due to Contamination of the lines, etc, copper needs to be replaced as well. Would it be worth it to Fix this baby or put a whole new system in?

    Upon arrival, breaker for ODU was tripped. Checked
    windings of compressor, windings reading 12.8, 12.8, and .7.
    Windings are no good. Additionally, continuity is present from
    power to ground indicating direct shortage inside of
    compressor. Customer will call installing company to

    • Jim Plummer says:

      Brian,

      Everything you relay points to a burnout which does contaminate the lines and the inside coil. An 8 year old system makes repair efforts questionable since repair are labor intensive and they do not come with the warranties that are included with new equipment. Never hurts to get a second opinion if you do not have complete confidence in a bid.

      Jim

  31. Cathy says:

    I woke up this morning with fumes in the air and heard the air condition running, but the air condition switch had been turned off before I went to bed. I checked the vent and heat was coming up through the it with a bad fume. I tried switching to cool and the air did change, but when I turned it off the unit continued to run. I then switch to heat and the unit kicked into heat mode, but when I switched it off the same thing happened. The unit continued to run with heat and spewing fumes into the air. I looked outside at the unit and noticed that the fan was not running, but the inside unit was running. I couldn’t figure it out. The only thing I could do to stop the unit from running was to turn off the circuit breaker for the a/c. Do you have any advise as to what might be happening?

    • Jim Plummer says:

      Cathy,

      Gas furnaces over 20 years old often had fan switches that brought the fan on after the fire box reached a preset temperature. Here is Texas that temperature can be reached by a hot summer day and the fan runs even though the thermostat is turned off. There is no malfunction when a gas furnace does this. The solution is to keep the furnace cooler during the summer or turn the power off as you did on the hottest days.

      If is not 20 years old then I would locate the wiring diagram on the furnace and then start troubleshooting by measuring the voltage at the fan motor while it is running. Using the wiring diagram as a guide I would then work my way through the wiring diagram from the motor toward the power source until I discovered which component is supplying the power when it is supposed to be turned off.

      Jim

  32. Ian says:

    Came home from work and wife told me air conditioner wasn’t working. Checked and I can hear a sound at the air conditioner. I shit the breaker off and sound was gone. I haven’t checked with a voltage meter but it sounds like the AC unit has power. So I spun the fan wand it started to spin. It’s still spinning but not very fast.
    Do you think this is a capacitor? Or the fan motor?

    • Jim Plummer says:

      Ian,

      I always replace the fan motor and the capacitor when the motor has to be started by hand.

      Jim

      • Dean castro says:

        Jim my connector on my a.c. is buzzing but nothing turns on any solutions

        • Jim Plummer says:

          Dean,

          I assume you are talking about the contactor. You can replace it and see if it gets better, or you can shut off the power to both the inside unit and the outdoor unit. Take a picture of the wiring connections and then take the contactor to your nearest U-FIX-IT store for free testing.

          Jim

  33. Brian says:

    Hi Jim –

    A little puzzled. A few days ago my wife and I realized the air on our first floor was not being cooled by our Trane XL16i outdoor unit. The air handler is working fine – plenty of air moving through the inside vents, but it’s warm and the temp never gets to the thermo setting, causing the unit to run continuously. The outdoor unit’s compressor is NOT running (or humming what what I can tell), but the fan is operating at full speed. No hot air is coming from the outdoor unit either as it should be, it’s actually ambient temperature. With the fan working and the compressor not, can this still be a capacitor issue? I think I saw a bulge in the top of the capacitor when I had the panel off, but I would think that that would kill the fan, too, no? Thanks for any help!

    • Jim Plummer says:

      Brian,

      Yes, it can be the capacitor. A bulge on the top of the capacitor usually indicates a bad capacitor. It is possible for only one side of the capacitor to fail. Take the capacitor to the nearest U-FIX-IT store for free testing or simply replace the capacitor and see if the compressor starts and runs.

      Jim

  34. Manny Crisol says:

    Sometime in May 2016, I tested my Central Air is working to prepare for summer. The fan outside was not turning. At first I suspected the thermostat. Then Researching the internet, the most common problems I learned were the capacitor and contactor. I replaced them the unit worked then this august it stopped again. The vents were blowing air but the fan is not turning. Does this mean my compressor is working? Does this mean now that I have to replace the fan motor?

    • Jim Plummer says:

      Manny,

      If the capacitor is good and 220 volt power is present at the motor, then the motor is bad if it is not turning.

      Jim

      • Manny Crisol says:

        Jim,
        The contactor, Capacitor, Fan Motor are all new. Then, I ran the sytem and the fan worked for about 30 minutes. Then the fan stopped again. I replaced the Thermostat still the fan doesn’t turn.
        I opened the system thinking that perhaps the wire contacts might be loose—tightened everything–still won’t work. I have only 3 wires to thermostat: red(power-shows 30 v in tester when tested with Green . tester shows 16 volts across the white (used for cool and plugged into the Y port) there’s no heat connection. My heat is controlled by a different system. What am I missing?. How do I test whether power is being delivered to the motor? Why did it work for a while and then stopped?

        • Jim Plummer says:

          Manny,

          If there is 220 volts going to the motor and it is not running then either the motor or the capacitor is bad. If motor is bad after only thirty minutes, I would verify the new motor is a good substitute for the motor it is replacing. I would verify the new capacitor matches the new motor. I would verify the new motor is set up to turn in the correct direction. I would verify the fan blade is mounted so the air blows out the top and that it is positioned correctly in the shroud. It is unusual for a new motor and/or a new capacitor to fail so quickly, consequently, I would be looking at everything surrounding the replacement to see if there is a cause of this premature failure.

          If there is not 22O volts going to the motor then use a volt meter to work back towards the power to discover which component is blocking the power.

          Jim

        • Manny Crisol says:

          This is an additional question. Can a capacitor go bad in a few days?

          • Jim Plummer says:

            Manny,

            Yes, a capacitor can fail in a few days, but is a rare occurance if it has been correctly matched to a good motor. A capacitor can fail quickly if it is connected to a bad motor. I never reuse a capacitor that has been connected to a bad motor regardless of how short a time power was applied. I always install a new capacitor with a new motor installation.

            Jim

  35. Cassie White says:

    Hello Jim,

    Yesterday, we had a company replace the capacitor and also a fan cap that was reading zero and it should have been at 5. The original issue was the house not cooling and the fan wouldn’t spin it just made a really loud nose like it was getting power but no movement. The tech said the capacitor was bad.

    Now today in the heat of the day it will not cool the house, every time I turn on the ac it makes the temp in the house climb. I checked the pipe to see if it was frozen because it was running on auto from 88 degrees down to 78 degrees last night.

    Any suggestions would be greatly appreciated as my home warranty company wants me and my children to sit another 72 hours without ac.

    • Jim Plummer says:

      Cassie,

      I am sorry, but there are not enough symptoms in your note to point toward a specific problem. Is the fan motor still running? Is the compressor running? Is there power going to your outdoor unit? These answers could help narrow down the possibilities.

      Jim

  36. Wendy says:

    When my husband came home yesterday our AV unit was squealing and the temp in the house was 78, it was set on 73 and it was around 90 outside. The fan was not turning. We turned it off and then turned it back on this morning and the fan was still need t turning, so I put a stick in it and turned the blades and they are now turning, but the air coming out of the vents is not cool. How long should it take the vents to throw cool air and if it should immediately and it isn’t what could be wrong with it?

    • Jim Plummer says:

      Wendy,

      I always replace the fan motor and capacitor when it needs to be started with a stick. It is unlikely fan motor is turning at full speed. Running the compressor without the fan motor running at full speed is not recommended. It causes the compressor to experience higher than normal internal temperatures and pressures. This is a good time to clean the indoor and outdoor coils if that has not been done recently.

      Jim

      • nichole says:

        How do I clean the coils, my ac unit the fan is, spinning and it’s blowing out cool air not. Cold Air from the vents

        • Jim Plummer says:

          Nichole,

          The indoor coil can be cleaned by removing the access panel that covers the coil. Shutting off the power is always a good idea. Following the Freon lines coming from the outdoor unit will lead you to the indoor coil. Coil cleaner that is designed for cleaning the indoor coils is available in pressured spray cans from U-FIX-IT Appliance parts. Coil cleaner for indoor coils does not have to be rinsed with water but rinsing with water improves the cleaning process. A brush may be required if the dirt on the coils is not washing off. In extreme situations the coil must be removed by a technician and powerwashed. Oftentimes a mirror and light will be required for inspecting the degree of success of the cleaning process. The cleaning process is much easier when the cleaning is done on a regular basis and the filters have been changed as needed.

          The outdoor coil is cleaned in the same manner by shutting off the power and removing panels as needed to gain access to the coils. It is much easier to clean the outdoor coil because access is better.

          Jim

  37. Adam says:

    Might be a dumb question but I’d rather be cautious and ask. Our new central air system just stopped working. The indoor fan unit works but just blows hot air (the outdoor unit is completely dead). I noticed a Milbank Series u3800 box and it is switched to off. I was wondering if maybe a breaker was tripped and I can safely lift this to “on” to try to resolve (or is this meant to always be on the “off” position?)

    • Jim Plummer says:

      Adam,

      If it was my unit, I would turn a “tripped” breaker on and see what happens. Random surges can trip breakers. A short in the outdoor unit will trip the breaker immediately when the breaker is turned back on. If the breaker trips soon after being turned back on, then the source of the trip needs to be determined.

      Jim

  38. Rod Parshall says:

    Jim, I have a problem with my outside unit. Every once in a while the ac will come on, but fan outside is not on. I push the what I call a reset button and it sometimes starts fan, and sometimes I have to use stick to start fan. A tech came yesterday and found a wire that looked like it was touching another and shorting out at times. He fixed that and all was well until today. Unit came on but not fan, so I pushed in reset again, and it starts working. I have no equipment to check voltages. You think the fan motor is bad. Unit is a 10 SEER Rheem, about 18 years old. Fan motor was replaced about 6 years ago. Thanks for any advice.

    • Jim Plummer says:

      Rod,

      A motor that will start and run with a push of a stick is a motor I would replace.

      Jim

      • Rodney Parshall says:

        Jim, I have replaced capacitor, but problem still there. I believe fan motor is bad since I can hear compressor start and fan moves a little then starts, or, compressor stops after maybe 20 seconds. If I get outside quick enough the I can move blade to get it started. I have ordered a new motor and think I can install myself after watching many youtube videos. “Thanks” for all you do here on this site.-Rod

        • Jim Plummer says:

          Rodney,

          Be sure to install a new capacitor that matches the new motor. Never reuse a capacitor that has been installed on a bad motor.

          FYI, it shortens the life of your compressor to allow it to run without the fan motor running.

          Jim

  39. Eric Walter says:

    Hi, I’ve recently run into some problems with my outside AC unit. It’s a Goodman, and from what I’ve been told, it’s about 9 years old. Never gave me too much trouble (though it’s always been so-so at keeping the house cool during summer in Louisiana) until last week. Around that time, the outside unit would randomly shut off during peak heat hours (1pm or 2pm) and the indoor vents would just be blowing room temp air. If I go to my thermostat, turn it on and then off, the outdoor unit will start to work again, and the air will also be cool in the house. My wife had her dad’s friend come and look at the unit and he said he’d just replace a drip pan and unclog a pipe in the attic. That was 2 days ago and I’m still having to restart the outside unit from my thermostat every day because it shuts off around 1pm or 2pm. I did a bit of research on google and found that maybe my outdoor coils may be dirty (upon inspection, they were pretty filthy and I doubt they’d even been cleaned).

    Could this be the culprit? I’m hoping I don’t have to buy an entirely new outdoor unit because apparently they don’t sell my model anymore and I’d have to get all the pipes and whatnot in my attic swapped out as well.

    • Jim Plummer says:

      Eric,

      Yes, the dirty coil on the outdoor unit could be a contributing factor. A dirty indoor coil can be a part of the problem as well. Dirty coils can cause the compressor to shut down on an internal safety. The dirty coils in combination with the hottest parts of the day during the summer could be the cause. In any case, cleaning the coils, changing the filter and opening all the indoor vents is a good starting place in the troubleshooting process.

      The next time the a/c is blowing hot air, take a look at the outdoor unit to see if the fan motor is running. A bad or failing fan motor that shuts off on internal safety can cause the compressor to shut down as well.

      Jim

  40. Jesse says:

    Hi Jim,

    We have a two year old Heat pump, we have woken up to a warm house two times this week where the target temperature is set to 75 degrees, but the t-stat reads the inside temp at 78, the furnace fan keeps blowing but the outside condenser unit is turned off. Could this be a safety measure to protect the compressor from these temperatures in DFW or do we have a problem with the unit somewhere?

    Seems like if we turn the power off for a few minutes, then back on the system runs as normal for a couple of days. the first occurrence we noticed was Monday then again today.

    Thanks for any help or comments you can provide.

    • Jim Plummer says:

      Jesse,

      When the unit stops is the time to do the troubleshooting. I would first try spinning the fan blade with a stick. If it starts and runs, then I would replace the fan motor and capacitor.

      If the motor does not start in the last step, then I would check for 220 volts coming into the contactor and 220 volts leaving the contactor. If there is no voltage leaving the contactor, I would check for 24 volts going to the contactor coil.

      If there is no 220 volts leaving the contactor and the 24 volts is present, the contactor is bad.

      If there is no 220 volts leaving the contactor and no 24 volts is present, then I would use the wiring diagram on the furnace to trace the 24 volt circuit and find what is blocking the 24 volts.

      If there is 220 volts leaving the contactor, then I would replace the motor and capacitor. There is an internal safety on the fan motor and the compressor. If the fan motor stops running on its internal safety that can cause the compressor to cut out on its internal safety.

      You can call the nearest U-FIX-IT store for personalized help over the phone at no charge.

      Jim

  41. Andy says:

    Hi Jim,

    My A/C seams to run fine at night but during the day it does not keep my house cool. I have it set for 76 degrees and during the day it gets up to about 87 degrees. Sometimes it blows cool air and sometimes it blows what feels like room temp. air. We live in Florida so it has been really hot, but been in this house for 6 years and never had this problem. I know you will probably need more info so just let me know what you need.

    Thanks,

    Andy

    • Jim Plummer says:

      Andy,

      Are you checking the outdoor unit during the heat of the day to see if it the fan motor or the compressor is cycling off and on? Motors and compressors run at higher temperatures as they approach the end of their life? The heat peak of the day can cause them to cycle off on the internal temperature safety switch so they don’t burn. They run continuously until the indoor thermostat is satisfied when they are operating properly. Of course the indoor blower motor should be running continuously also.

      If the motor and compressor are not cycling off, then I would check to make certain the indoor and outdoor coils are clean. The outdoor fan motor should be moving the air vigorously. All of the vents and all of the doors in the house should be open. The filter should be clean.

      I am assuming this unit has performed satisfactorily in past years at similar temperatures. If this is the hottest temperature the system has ever experienced then it is possible the unit is not sized for this much heat.

      Jim

  42. Juha says:

    Jim, this is a great AC DIY page!

    I´ve read through many comments and suggestions but I can´t find one that really fits to my problem.
    I am located in Sweden so my temp readings below are in degrees Celsius.

    My unit is a wall unit called Prem-I-Air EH0533.
    Info at http://www.prem-i-air.com/homepage.aspx?com=product&productid=1584&pg=1106&tl=1095 and the user manual with partial schematic can be found at http://www.prem-i-air.com/docs/1886.pdf
    A Swedish manual that has partial schematic of the electronics board on page 22 can be found at http://haceklimat.se/wp-content/uploads/2015/04/PMINISWH10W-manual.pdf

    My unit is brand new and had this issue already from the first run:

    It is for example is 25 deg C outdoors and about 28 deg C indoors in my small “electronics labb/computer room” at home.
    I set the unit to “CO” (i.e. cooling) and target temp at for example 18 deg C.
    Units starts to cool and it keeps cooling for about 15-20 minutes. I can see that the room temp drops to for example 24 deg C and then the compressor turns off while the fan continues to blow air.
    Room temp starts to rise rapidly again and at around 28 deg C room temp the compressor starts again but stops after 15-20 minutes when room temp has only fallen to around 24 deg C.

    I see no error messages in the display and the blowing fan keeps on blowing cold air as long as the compressor is running and when compressor turns off it still keeps on blowing air but now only the air that it sucks in from the outside.

    My feeling is that there is something wrong with one of the termistors causing the compressor to shut down too early. I am looking at the schematics in the Swedish manual but I am unsure if I should measure the termistor at connector CN1 marked as “ROOM” or the thermistor at connector CN4 marked as “PIPE” or the thermistor at connector CNx marked as “SW”. I am unsure of what “SW” mean in this case? but could it be the thermistor that is located in the rear opening of the incoming air?

    Maybe I should measure all three thermistors and what resistance should I expect when room temp is around 25 deg C?

    Or could it be that the unit has been erroneously filled with too low refrigerant from the factory (i.e. I would need a certified technician to check this)?

    • Jim Plummer says:

      Juha,

      Since the problem has existed since the initial install, I would look first to the installation. Identifying my own installations errors can be challenging since I tend to view the mistake as the correct action when reviewed. To mitigate that, I do a slow motion review of the install starting with making certain the components are matched correctly. Then I double check that every step of the installation checklist has been performed exactly as detailed in the installation manual. I question every step for a possible alternate interpretation. I give extra scrutiny to the steps that raised questions during the initial install.

      Once I am confident the install steps have been accomplished correctly. Then I study the system until I am confident how the system is supposed to operate.

      If the problem has not presented itself during the above process, I would call the factory service number listed in the manual. Factory service will be very familiar with the common installation errors for their equipment and may be able to guide you to a quick solution. The factory would be able to help you determine if you are experiencing symptoms of low refrigerant as well. The factory cannot always provide diagnosis, but they are very good at explaining how the system is designed to operate. Resistance values of thermistors can be found on line.

      New equipment can have malfunctions, but it is the exception rather than the rule. Installation error is the most likely problem.

      Jim

  43. tom d says:

    Great info here! I had my compressor stop working along w/ the fan. Checked voltage at disconect and at contactor, had 120 volts…thought all was good w/ breakers and control panel. WRONG!. After calling service guy, he found FUSES inside of disconecct panel! Hidden away…One was blown, thats why 120 volts and not 220. Duh….Great guy, didnt charge me anything!

  44. Lucy says:

    Hi I just had ac motor and capacitor replaced 2 days ago, and the temperature in the house is not falling to what I have set, it stays 2-3 degrees above the setting, making the house not comfortable and the unit constantly running to try to cool it down. What do you think the problem is?

    • Jim Plummer says:

      Lucy,

      Have you completed all the steps in the article? What is the outdoor temperature during the day? Is system keeping the house cool at night? I need more information to be of assistance.

      Jim

  45. Mike says:

    Hi Jim, thank you for being available. I came home today to my outdoor air conditioning unit not running. My first instinct was a stuck fan, but I checked it and it turned freely. Last year I had the capacitor replaced because the unit would not kick on. Today I noticed that neither the compressor or the fan would kick on. I shut down the unit for about 3 hours. Decided to check the voltage at the unit and it was 240v. Checking the contactor, I did have 240 at the contactor and 24v through the coil. I did not have a meter to check the mf at the capacitor. I decided to concentrate on the contactor. When I pressed in on the switch in the middle of the contactor, the unit kicked on. When I released it, it did shut back down. I decided to go into the house and turn the thermostat back on to run more testing, and low and behold, the unit kicked on and is now cooling the house. My question is, it must have kicked on because it had a chance to cool. Which part could it be, capacitor or contactor?

    Here are the specs of my unit: ICP Split System A/C 4 Ton 10 SEER Model: NAC048AKC3

    Thanks for any help you can give,
    Mike

    • Jim Plummer says:

      Mike,

      From your description I would be most suspicious of a stuck contactor which became unstuck when it was manually activated. If it was mine, I would replace the contactor since they are a common failure component and it is never fun to come home to a hot house. The contactor should have been closed since 24 volts was present.

      Jim

  46. May says:

    I purchased an AC 2 years ago. It has never worked at cooling my house down. Today it is 85 degrees outside, my house it at 80 and my thermostat has been at 72 all day. It just can’t keep up. The AC I have is supposedly larger than I need for my house. I know it isn’t exact but I have a 1050 sq ft house, 2 br, 1 ba and a Rheem 2 Ton 13 SEER Air Conditioner. I live in Norther California where it doesn’t even get that THAT HOT! I have had the AC installers out here dozens of times and they cannot say what is wrong. They have fixed leaks, freon has been low, say it is putting out what they want to put out, say I have good airflow, but my house doesn’t cool. I brought up my attic as I live in a triplex and I don’t know if the heat up there is so intense to be causing this. They have indicated in the past that is not possible. This last time they said maybe so…I am unsure what to think. I want to get another company in here to check. Is there anything these people could be missing? Could the unit be defective if they say airflow and temp is ok?

    Any help/advice is appreciated!

    • Jim Plummer says:

      May,

      Under normal conditions 2 tons should be sufficient to cool 1050 sq. ft. I would check the temperature drop between the air entering the return air and the air exiting the supply vent closest to the unit. If it is 12 degrees or more then the a/c unit is doing all it can do. The insulation in the walls separating your home from your neighbors can be critical if they are not setting their thermostat as low as you are.

      It appears you have a problem that a/c techs do not commonly run into. Your challenge is to engage a technician that will identify the problem with the system and/or the house. This is a very busy time of year for a/c techs and most will be reluctant to take on a time consuming challenge for a new customer when it will cause an old customer to have wait. Even so, you might try sending your letter to a number of the service tech companies in your area and see what their response is. You are looking for a service tech who has expertise and experience in both system design and in troubleshooting. The technician you are looking for will not be the cheapest, will not be able to get to you quickly, but they will absolutely guarantee the problem will be identified.

      Be prepared for the problem to be with the system design and/or with the house. The a/c itself is almost a minor player in the process of cooling a space.

      Jim

  47. June says:

    We have been facing fan blades broken or stuck and blades or/and motor need to be changed @ server room
    This happened to the old and new units which we bought in 2 years ago
    Can we know the cause of the problem ? is it the model issue or positioning of the condenser?

    Thanks

    • Jim Plummer says:

      June,

      Your note does not contain enough information to give any specific recommendations. It was unclear if it was the outdoor unit or the indoor unit. Fan blade cracks are often due to vibration or the blade being out of balance. Restricted air flow is a consideration as well.

      With more information I might be able to offer better advice.

      Jim

  48. Dave says:

    Outside unit of system that is used to cool rarely fan stopped running. Troubleshot to bad part of cap using Fluke DVM & proved compressor running OK and Fan also running connected briefly to compressor side of cap.

    Installed exact replacement cap & compressor now does not run – also appearing to stop fan running, when compressor draws high current while trying to start. Low voltage to contactor is OK and contactor is operating, switching 220V to output side. Current draw of fan when running is about 4 Amps. When contactor operates, fan briefly draws over 100 amps, buzzes and current drops to zero. Presumably thermal overload.

    I’ve just pulled the contactor and cleaned / checked the switching poles for oxidation etc.

    Reconnected everything using circuit diagram and photographs to be sure.

    Am I really unluckly and the compressor failed because the fan quit and the thermal cut-ouot did not protect it?

    Any more steps before I call an HVAC guy to replace the compressor?

    • Jim Plummer says:

      Dave,

      Although possible, I am skeptical of the compressor failure. As I understand it, the bad motor has not been replaced. It is possible the bad motor has damaged the new capacitor. In any case I always fix the obvious problem first. If it was mine, I would check for continuity between the three posts on the compressor and check for no continuity from the post and the housing. If the compressor passed those checks, I would replace the capacitor (again) and the motor at the same time. It is amazing how often the secondary problem disappears when the primary problem is fixed.

      Jim

  49. Tim Peoples says:

    Hi Jim, my central air unit is blowing from cieling blower but not blowing out any cold air. The fan on the unit outside of the house does not work unless I push it to jump start it, but I still only get warm air. While the fan is off I hear a faint humming noise that reminds me of standing next to an electrical box. The motor also seems very warm while the fan is off. I also hear a buzzard sound about once a minute even if the fan is on or off. My unit is Goodman CPKJ24-1A. I ordered a capacitor but it hasn’t arrived yet. I hope this fixes the problem . Any thoughts.
    Thanks,
    Tim

    • Jim Plummer says:

      Tim,

      It can shorten the life of the compressor to allow it to run without the fan motor running. I would cut off the power to the outdoor unit until the fan motor is running again if it was mine. While waiting for the capacitor I would make sure the indoor and outdoor coils are clean and that your filters are clean. If the capacitor does not fix the problem, I would replace the motor and the capacitor. I never reuse a capacitor that has been installed on a bad motor no matter how short the time.

      Jim

  50. Victor says:

    Hi Jim,
    The external fan on my AC wasn’t working, so I ended up replacing the motor and the capacitor.
    The issue now is the motor runs for a while ( 10-15 min ) and thermostat switch it off. Then it doesnt restart. The compressor runs for 10 seconds, but the Fan doesn’t . The controller keeps trying to make it work, so every half minute or so the compressor starts again, but not the fan. I switch off and wait a few minutes, then the fun restart ok, but after 10-15 minutes it stops and doesnt restart.

    What else can be bad ? The contactor seems ok, as the compressor runs. thx

    • Jim Plummer says:

      Victor,

      The symptom points toward a motor that is overheating and cutting off on the internal overload. There are several reasons a new motor will overheat.

      Some are as follows:
      The motor is not sized correctly or is the wrong RPM.
      The motor is turning the wrong direction(verify the air is blowing up briskly).
      The fan blade is positioned incorrectly or installed backward.
      A dirty coil or obstructed coil.
      The capacitor is not matched to the motor.
      The voltage being supplied by the power company is wrong.

      Compressor life will be shortened by allowing it to run without the fan motor running. It is best not to do that.

      Jim

  51. Jaece says:

    I did all steps to find my problem. Outside unit not running at all. Capacitor was bulging like picture of all bad ones I’ve seen on Internet. The tech from company that installed unit said it was indeed bad and I bought a new one. Everything I’ve read said make sure numbers/ratings are same. Bad one was part GE 97F9856 ratings of 40uf-5uf, 440vac, +6% -6%, 50/60Hz. Replacement tech gave me was a Titan Pro part # TRCFD455 and ratings of 45+5, 440/370vac, +/-5%. I asked him about the numbers being different. He said that it was totally fine. Installed new capacitor, turned breakers back on & power on then A/C switch on. Unit was humming but fan blade was not working. I did a stick test to spin blade and blade spun freely but did not kick on. I turned A/C off and now I’m here. Did the tech give me wrong capacitor? Or is my issue a fan motor? Thank you in advance for any advice!

    • Jim Plummer says:

      Jaece,

      U-FIX-IT would not make that substitution since we adhere to +/-10% of mf (microfarad) rating as our guideline. It is, however, a fairly common practice to make that substitution. Even so, the motor uses the 5 mf side of the capacitor which is correctly sized. If your motor requires a 5 mf capacitor, then the symptoms are pointing toward a bad motor.

      Jim

  52. M says:

    Our air has never been right since we have been in this house. We purchased the house new. They have been out here several times and it has worked a while but then the same problem. Now it will work but then seems that the fan sound in house stops and it gets hot. It’s blowing out but not as strong later at night. The Hvac company said the worker that out unit in and who has come out to fix it no longer works for them. They also said they will charge 85 an hour just to look at it now. It’s been over three to four repairs since we have been here. I guess it’s time to call the better business bureau.

    • Jim Plummer says:

      M,

      The symptoms provided are not sufficient to point toward a specific problem. It is important to go through all the steps in order to isolate the problem.

      A second opinion may be productive as well. Remember the cheapest service call is not always the best service call.

      Jim

  53. Andy H says:

    Jim,

    Came home today and AC wasn’t working. Fan is blowing warm air out the vents, outside fan is not working and I don’t hear any noise suggesting it’s trying to turn on. Per your suggestion, I’ve tested power to the contactor and have power in and power out, but do not have the 24 volts on the coil portion of the contactor. What do I do from here?

    Thanks,

    Andy

    • Jim Plummer says:

      Andy,

      The next step is to verify 24 volts being sent from the terminal board on the indoor unit. Both the wall thermostat and the outdoor unit are tied together at the terminal board on the indoor unit. The 24 volt transformer is usually located on the indoor unit as well. It is very easy to “blow” the 24 volt transformer by shorting the wires. There is no large spark when this happens.

      If 24 volts is present at the indoor terminal board then the problem is between the terminal board and the outdoor unit. I would look for a broken wire.

      If 24 volts

        is not

      present at the indoor terminal board then use the wiring diagram located on the indoor unit to trace the circuit back toward the transformer until the problem is located.

      Jim

  54. Jessie Cole says:

    Hi Jim,
    I live in FLorida and it’s been in the upper 90’s with high humidity for a week. Around the same time every day my compressor stops working . (About 2pm-3pm) . The AIr handler and condensor fan are still working just not the compressor. We turn it off till about 6pm and the compressor always comes back on until the next day when it’s the hottest.. Any tips or ideas?

    • Cliff says:

      Jessie,

      Was curious if you solved your problem yet, and if so, what the problem was? My home AC is essentially doing the same thing. Everything works fine and it cools like it’s supposed to when I turn it on in the morning, but in the afternoon it just blows warm air. Like yours, the condenser fan is still running, but the compressor isn’t. The compressor tries to start (if you’re outside by the unit you can hear the compressor trying to start every few minutes or so), but can’t. I turn the system off via the thermostat, and it seems no matter how long I leave it off for, I still have the same problem – until the following morning when it’s cooler inside and outside, then everything works fine. If you figure it out, or get any answers I’d sure like to know. Thanks!

      • Jim Plummer says:

        Cliff,

        No follow up word from Jessie. You do not mention any voltage readings. It is impossible to move forward in the troubleshooting process without knowing voltage. If you followed all of the steps then the symptoms are pointing toward a bad compressor.

        Not the news anyone wants to hear.

        Jim

    • Jim Plummer says:

      Jessie,

      The failure during the hottest part of the day suggests the compressor is cutting out on the internal safety. I would verify 240 volts is going to the compressor while it is stopped. If the 240 volts is present then make certain both the indoor coil and outdoor coil are clean and allowing air to pass through them freely. Verify the air filters are clean and that all of the registers in the house are open with no rooms shutoff with closed doors. Any restriction of air flow through the coils indoors or outdoors can cause the compressor to run hot.

      If all of the above is in good shape, then it is time to have a qualified and experienced a/c tech check the refrigerant charge in your system. Incorrect charge can cause compressor overheat, but so can an old compressor on it’s last legs. The a/c tech can help you know which one it is.

      Jim

  55. Tandryn says:

    Hey Jim, my outside unit is not spinning and i dont hear the compressor. When i turned the unit off i heard it click outside. But in side we feel air coming out the vents, we hear the system on inside. But when i look outside nothings working. N the house is not cold as it should be to me i have it on 73 but the thermostat reads 84

    • Jim Plummer says:

      Tandryn,

      I would use a multi meter to verify there is 240 volts arriving at the outdoor unit. It may be as simple as a thrown circuit breaker.

      If 240 volts is present, the contactor and the capacitor should be tested. They can be removed and taken to the nearest U-FIX-IT store for free testing. Turn off the power to both the indoor unit and the outdoor unit before removing wires. Taking pictures of the wires can help with installation.

      Jim

  56. Jim says:

    Hi Jim,

    Jim here as well. Thanks for your input / sharing your experience on this site.
    Here’s my situation: We had a new panel swap in, for older electrical distribution equipment, within the last month. I’m not sure if this is relevant information, but we had continual problems with one leg of the 2 fuses (30A) blowing, and I would regularly replace a fuse there.
    Since the new panel install, we have a 30/2 breaker feeding the outdoor condensing unit – and we had about 2-3 weeks of solid performance, and then the issue came up 2-3 days ago with the compressor not running when everything else is. The fan on the outside air unit was running, but no compressor action.

    This seems to be a single output contactor and single capacitor design, so I’m now trying to figure out what to do to zone in on the issue more clearly. I had someone mention to me to look at utilizing a hard start kit for the compressor, and I also had a separate person that brought out an ohmeter and put them on the compressor terminals. I didn’t fully understand his methodology, but he seems to think that the compressor was bad – however I’d like to independently verify this myself, best I can. I am also considering options best I can – as to next steps given the possible things it could be at this point.

    • Jim Plummer says:

      Jim,

      The motor winding inside the compressor is two long wires. One wire for the start winding and one for the run winding. The ohmmeter can be used to determine if each winding (the long wire) is still in one piece. If the ohmmeter shows an “open” circuit (no connection between the leads) on either winding, the compressor is bad and must be replaced.

      The compressor is not a good “do it yourself” project. Specialized tools, knowledge and experience in needed for a good result. If the compressor is over five years old on a unit I own, I would lean toward replacing the complete outdoor unit.

      Jim

  57. Shen says:

    The fan on my outdoor unit did not run but, after I pushed it with a stick, it ran continously. However, inside the house there is still no cool air flow. The furnice sounds normal but I don’t know if the blower is working. How can I check and fix the problem? Please help soon. Thank you.

    • Jim Plummer says:

      Shen,

      If the motor requires a push with a stick to start, it is time to replace it. The motor is probably not turning full RPM when it is running. Secondary symptoms often disappear after repairing the obvious malfunction first.

      Jim

  58. James Porter says:

    Hello and thank you in advance.
    I’m stuck. I replaced my fan motor…before checking my capacitor…I replaced my capacitor on my outdoor unit. The ac started working and blowing cold air. It shut down an hour or so afterwards. I checked my contactor and it seems fine. When I press the center in the compressor turns on, lines get cold but the fan doesn’t turn on. The board is reading a brown out fault code. Any ideas?

    Thanks

    • Jim Plummer says:

      James,

      If the fan motor has 220 volts going to it and the capacitor tests good, then the fan motor is bad.

      You can take the motor and capacitor to the nearest U-FIX-IT for free testing.

      Jim

  59. Corey says:

    Hi Jim

    Can you explain to me the purpose and value of a hard start kit? Recently my outdoor fan was not blowing and I checked my fuse box and the switch had jumped off. I had a tech tell me I may need one. Please advise.

    Thank you

    Corey

    • Jim Plummer says:

      Corey,

      Corey,

      The purpose of a hard start kit is to provide an extra boost to the compressor during the start up. Hard starts can sometimes help an older compressor get a little more life. Many technicians install hard starts on units located in rural areas or areas where electric power may fluctuate. There is no downside to installing a hard start. It may or may not help a compressor struggling to start.

      Jim

  60. Sol says:

    My ac unit is running inside but not outside. There is no type of noise coming from it

    • Jim Plummer says:

      Sol,

      If the outdoor unit is not running, start with checking the power going to the outside unit. If you have power and the outdoor unit is not making any noise, then cutoff the power to the outdoor unit and the indoor unit. Take picture of the wire connections to the contactor. Remove the contactor and take it to your nearest U-FIX-IT store for free testing.

      Jim

  61. Bob says:

    Hi Jim,

    Please help me out. I have a ductless AC. A couple of days ago, the indoor unit shuts itself off. I turn it back on, but it blew hot air. I checked the outdoor unit, the fan is working but I don’t hear the compressor. I changes the running capacitor, but it did not fix he problem. Do you think adding refrigerant fix the problem? The unit is only 6 years old and has not used much. Do you think the compressor is dead? If so, how can I make sure. Thanks for your support.

    • Jim Plummer says:

      Bob,

      I do not recommend adding refrigerant unless you have the tools and expertise to know for certain the system has lost refrigerant. I recommend calling an a/c tech to check the refrigerant if that is what you are suspecting. If refrigerant is added, the leak should be located and repaired.

      On the compressor, use a multi-meter to measure the voltage going to the compressor. If there is voltage going to the compressor and the compressor is not running, it is likely bad since you already replaced the capacitor. If there is no voltage going to the compressor then look for a wiring diagram on the unit and use it to find the faulty component that is blocking the flow of electricity.

      Jim

  62. Chris says:

    Jim,

    Can a low refrigerant level cause the compressor and fan to shut down? Is there typically a pressure switch that could do that? My system was low last year, serviced, and I’m wondering if it could be related/low again. Similar symptoms have been happening recently low airflow out of vents due to ice buildup, I shut it down, melts, then good for a while. But the whole outside unit being dead is something new. If a low refrigerant level can cause outside unit shutdown, can refrigerant be added effectively to a system while the compressor is not running?

    • Jim Plummer says:

      Chris,

      Yes, these symptoms could be caused by low refrigerant. Some systems do have a pressure switch to shut down the outdoor unit. Anytime refrigerant is added to a symptom without finding and repairing the leak, you will continue to lose refrigerant. A properly sealed system will not lose refrigerant.

      Adding refrigerant is best done by a qualified, experienced and properly equipped service tech. Adding refrigerant without repairing the leak is a temporary fix and can cause damage to the compressor.

      Jim

  63. Ryan says:

    hi, Jim,

    I see the above post thread and really impressed by your professional expertise the generosity to help people. I have some issue with my A/C system too and wonder if you can provide any advice too?
    Basically, my A/C is the same age of my house 1990, so 26 years not. The outside unit stopped working, the indoor unit still blow air through the vent inside the house from time to time (sometimes it just stops by itself, and seems will start up after a while again.). But motor fan in the outside unit just not working. this used to happened 5, 6 years ago, I have the home warrantee insurance company guy came and what he did is put some oil into the center part of the fan motor and put the motor back into the case of the outside unit. Then the fan spinning, and it seems working, but certainly, the efficiency of the unit is not good as expected. But, the issue just happened year after year. So, it needs manually putting oil again when summer came before I can make the fan to spin again.
    Is this symptom normal – need to put oil to the fan motor every year?
    your professional advice and help is really appreciated.
    thank you so much.

    • Jim Plummer says:

      Ryan,

      If it was my unit, I would replace the fan motor. Unless your motor has oil ports, it has permanently lubricated bearings which are not designed to be lubricated after installation.

      Jim

  64. Brian says:

    Hi Jim,

    It is really nice of you to help people out this way. Thank you! I came home today and my air conditioner stopped working since this morning. It only blows warm air. The outside unit makes a buzzing sound when the thermostat is set to cool. The outdoor fan does not run, and I don’t hear the compressor. Unless that buzzing sound is the compressor running. Sounds like high voltage, is that the compressor? I used to be an air conditioning tech, but that was a long time ago now.

    It is a Bryant 4 ton 113ANA048-A.

    Thank you,
    Brian

    Thanks again for any help you can offer,
    Brian

    • Jim Plummer says:

      Brian,

      Check the breakers in your main breaker box for your outdoor unit. That may be all it is.

      If you have 24O volts at the outdoor unit, you can take your contactor and the capacitor to you nearest U-FIX-IT for free testing. Be sure to disconnect electrical power to the outdoor unit and to the indoor unit before removing the contactor. Don’t forget to take pictures of the wiring connections.

      Jim

  65. Gene says:

    Having a central air problem. Had a Tec come out twice and still can’t figure out the problem. Ac starts out cold for a few minutes then the hole system out side shuts off. Fan and compressor at the same time. It will restart again after about 30 seconds and run for about 10 to 15 seconds be for it shuts off again. Ac tec bypassed pressure switch to see if that was the problem and it worked for about a hour after he left then started blowing out hot air again. Can you please give me some advice on this. I already made sure every thing is clean and clear of trash and bushes and all.cleaned out side area with water hose and still nothing.

    • Jim Plummer says:

      Gene,

      Intermittent malfunctions can prove challenging. The problem can only be located while the unit has stopped due to the malfunction. A multi-meter will be required to read voltage. A wiring diagram is usually attached to the inside of one the panels on the outdoor unit. When the unit stops verify there 24 volts present at the contactor. If 24 volts is not present, then trace the circuit back inside the house to find where it is being lost.

      If 24 volts is present, verify there is 240 volts both entering the contactor and exiting the contactor. If power is going in and not coming out, it is a bad contactor. Otherewise, use the wiring diagram to determine the section of the circuit that is common to both the compressor and the fan motor. Look for the component in the circuit that has stopped the power from moving forward and replace it.

      If the pressure switch has turned off the power, then it must be determined if the switch is defective or if there a pressure fluctuation that is causing the switch to actuate. Troubleshooting the sealed system is best left to experienced and qualified technicians who will have the right tools to diagnose and repair the system.

      Call the nearest U-FIX-IT store if you have questions while diagnosing your malfunction.

      Jim

  66. Joshua says:

    I live in an apartment with a box air conditioner. The unit is about 6 years old at this point. When it is hotter than 80* outside, the unit has a very hard time cooling down my apartment at all. The air conditioner will blow cold air for approximately 25 minutes, at which time, the fan will kick off – but the motor will continue running extremely loud, with no air coming out.

    This air conditioner is successful at cooling down my apartment by about 5* in this time period. With the time it needs to cool down, before the fan kicks back on, the temperature in the apartment has already gone back to what it was – very close to outside temperatures.

    Is this how these air conditioners are supposed to operate? I feel that I can distinctly remember this working a lot better when it was new.

    I appreciate any response! Thank you in advance.

    • Jim Plummer says:

      Joshua,

      Your malfunction description as I understand it; the fan motor kicks off and no air is coming out while the compressor continues to run. The fan motor may be shutting off due to an internal high heat safety switch being triggered by the motor overheating. The safety resets when the motor cools down and the motor resumes running.

      1. If your fan motor has a capacitor take it to your nearest U-FIX-IT store for free testing.
      2. Extremely dirty coils can cause an overload on the motor resulting in high heat. Cleaning the coils may correct the problem.
      3. Finally, the motor may be at the end of it’s life. Your symptoms are common for a motor that is failing. 6 years is within the range of average motor lifespan.

      Call the nearest U-FIX-IT store if you need additional help.

      Jim

  67. joe says:

    Hi. I just bought a wall unit and turned it to “low fan” setting. Within I think a few seconds after it started, I could hear it slowing down, which it continued to do until it came to stop, which only took like 2 minutes. I am charging my cell phone so I can video record it when I turn it to “high fan” setting. I turned to “high fan” setting just for a second to see if it would come on and it did. Can you tell me what types of things could be the problem here?

  68. Robert Bach says:

    I have a 15 year old Carrier air conditioner that went out. Diagnosed problem as being failure of outdoor fan motor. Replacing OEM condenser for fan motor and the dual capacitor will cost about $1100. Should I consider just replacing the entire air conditioning unit for $4000+ instead of having it repaired? I use my unit sparingly during the summer months. Thanks for any advice you may have concerning this.

    • Jim Plummer says:

      Robert,

      Mechanical devices tend to degrade quicker when they have significantly less than average use. Your compressor is already twice the age of the average life span of 7 years. There is the exceptional compressor that can go to 25 or 30 years, but that is the exception. Other factors to consider: the replacement motor usually has a 1 year warranty and the condensers usually have a 5 year warranty. A new condenser will probably be significantly more efficient, but the indoor coil would need to be replaced to match the condenser in order to realize all of the efficiency gain.

      If it was mine and I was planning on keeping the property 2 years or more, I would probably lean toward replacing the condenser and the coil. I would also replace the indoor blower unit as well just to keep everything matched and the same age. Of course, if you install the motor yourself(it is a pretty simple task), it would cost significantly less and that would make replacement a more attractive option. Call the nearest U-FIX-IT store to get a better idea of the task and the cost.

      Jim

  69. janet bloodworth says:

    My inside blower and outside unit does not come on when I have my thermostate on auto / cool.
    If I put my thermostate on cool/ and on the inside blower comes on but not the outside unit. Can you give me a few Idea’s.

    Thanks Janet

    • Jim Plummer says:

      Janet,

      There is no quick answer for you. Remove the panels of the indoor unit and look for a wiring diagram. Take a picture of the wiring diagram to the nearest U-FIX-IT store for personalized help with troubleshooting.

      Jim

  70. sara says:

    My air conditioner is not working at all, its on but noting is coming out, Its 90 here and my house is way to hot what to do in this situation?

    • Jim Plummer says:

      Sara,

      If your outdoor unit is running then take the capacitor and blower motor to your nearest U-FIX-IT for free testing. Be sure to disconnect electrical power to the indoor unit before removing the contactor. Don’t forget to take pictures of the wiring connections.

      If the outdoor unit is not running then take your transformer to the nearest U-FIX-IT for free testing. Be sure to disconnect electrical power to the indoor unit before removing the transformer. Don’t forget to take pictures of the wiring connections.

      Jim

  71. Cathy King says:

    Help, please. The electricity went off twice in a row today. Of course, the air was on. When the elec came back on, the air only blows warm. The outside unit isn’t kicking on. What might the problem be before I call an HVAC and get taken for more than I have to? Thank you so much for the help.
    Cathy

    • Jim Plummer says:

      Cathy,

      Check the breakers in your main breaker box for your outdoor unit. That may be all it is.

      If you have 24O volts at the outdoor unit, you can take your contactor and the capacitor to you nearest U-FIX-IT for free testing. Be sure to disconnect electrical power to the outdoor unit and to the indoor unit before removing the contactor. Don’t forget to take pictures of the wiring connections.

      Jim

  72. Befuddled says:

    Last year we started experiencing intermittent issues with the outside aspect of one of our A/C units where inside unit would kick on but the outside fan wouldn’t spin unless pushed with a stick.

    It was diagnosed as a bad motor and we had it replaced, but, it seems the problems were just starting. After the fix, the air worked, but, the outside unit (condenser?) began running 24/7 unless we manually pulled the shut off bracket to kill the power to the unit. Since it worked, we didn’t think much of the inconvenience.

    This year, after plugging in the power shut off bracket, we fired up the system and everything kicks on, but, the air coming from the inside vents is warm. Also, not sure if coincidental or of note, but, the air being blown by the outside condenser fan is significantly cooler than that blowing of our upstairs unit (we have 1 for upstairs / 1 for downstairs).

    We figure it’s probably a job best done by service pro, but, any insight on what they may say / diagnose would be appreciated!

    • Jim Plummer says:

      Befuddled,

      You are describing two malfunctions. The cooler air may be an indicator the compressor is not running. You can take the capacitor to the nearest U-FIX-IT store for free testing. Be sure to disconnect electrical power to the outdoor unit and take pictures of the wiring connections before removing them.

      The second malfunction is the continuous running. Since it started when the fan motor was replaced, you may want to use the wiring diagram to make sure the new motor was wired in correctly. If the wiring looks good remove the contactor and take it to the nearest U-FIX-IT store for free testing. Be sure to disconnect electrical power to the outdoor unit and to the indoor unit before removing the contactor. Don’t forget to take pictures of the wiring connections.

      Jim

  73. SAAD says:

    MY INDOOR AND OUT DOOR FAN WORK BUT AC NOT COOLING AND MY AC IS 1.5TON FULL DC INVERTER AC AND SHOWS AMPERE 1.9

  74. Jae says:

    My indoor until will cycle on but my outside unit is not doing anything… What should I do?

    • Jim Plummer says:

      Jae,

      Start with checking to see if you have 240 volts arriving at the contactor. If you have voltage at the contactor then take the contactor to your nearest U-FIX-IT store for free testing. Be sure to disconnect electrical power to the outdoor unit and to the indoor unit before removing the contactor. Don’t forget to take pictures of the wiring connections.

      Jim

  75. Yasir says:

    hi jim my air conditioner unit has cooling problem since 2 days ,some times it starts cooling and sometimes it do not cool the room .when it do not give cool air i have observed its outdoor unit its fan was not running .after several on /off sometimes it starts cooling.
    please guide what to do

    • Jim Plummer says:

      Yasir,

      A failing capacitor or fan motor can be the problem. You can take them to your nearest U-FIX-IT store for free testing. Be sure to disconnect electrical power to the outdoor unit and take pictures of the wiring connections before removing them.

      Jim

      • Yasir says:

        jim ,the problem occur when its too hot outside.when he temperature is moderate it works .
        now tell me what should i do…
        is it problem of gas inside compressor or something else.

        regards

        Yasir

        • Jim Plummer says:

          Yasir,

          Start with making certain the filter, the inside coil and the outside coil are clean. Whenever the unit is not cooling properly, check the outside fan motor to see if it is turning.

          Jim

  76. Eduardo Martimen says:

    Hello,

    Im having problems with my A/C system a Technician came to take a look into it and he told me I had to replace the Thermostat because it was not blowing air. I already did that finally the fan is working, also i change the filter and clean the condenser. But for some reason is not cooling my house at all I wanted to ask what else can i do to make it work? thanks

    • Jim Plummer says:

      Eduardo,

      Are both the outdoor fan and the indoor fan running now? Is the compressor running? Be more specific in describing what is working and what is not working.

      Jim

  77. Mari Moreno says:

    My Lennox ac unit wont start from outside. .. Bought a new fan and a new motor but it still won’t Start. What can the problem be?

    • Jim Plummer says:

      Mari,

      You should always replace the capacitor whenever you replace the motor. If the compressor is not running and the indoor fan motor is running, then take your contactor to the nearest U-FIX-IT store for free testing.

      Jim

  78. William Henry says:

    My AC unit fan will start up and run for about 15 seconds and shut done it will then start back up again. I replaced the capacitor and it still continuity to cycle. Any suggestions?

    Thanks you in advance for your help.

    Bill

    • Jim Plummer says:

      William,

      I would replace the motor if it was mine. Motors have an internal safety that shuts the motor off when they get too hot. Motors operating temperatures rise as the wear out. Take your old motor to the nearest U-FIX-IT for a replacement.

      Jim

  79. Johnny says:

    Jim

    Compressor is getting power consistently and tries to turn on for a second but only hums and turns off. Fan is turning fine.

    Thank You

    • Jim Plummer says:

      Johnny,

      Bad news, that is what compressors due as the fail. Sometimes, but not always you can buy a little extra life by adding a hard start to your compressor. There is no guarantee that a hard start will give be able to start the compressor and if it does start the compressor there is no way to know how much additional life you will get. It may be a day, a week or months. I would try the hard start available at U-FIX-IT if it was mine and then plan for the compressor replacement or the condenser replacement.

      jIM

  80. Anjil Rana says:

    My outdoor fan starts after 3-4 Minutes after switching the indoor Unit. Indoor unit is blowing hot air but as the fan revolve Cooling is fine and i think the fan starts with the compressor. Before it was working fine now. Can u help?? what is the problem

    • Jim Plummer says:

      Anjil,

      You are correct. The outdoor fan motor should run at the same time the compressor run. A failing capacitor or fan motor can be the problem. You can take them to your nearest U-FIX-IT store for free testing. Be sure to disconnect electrical power to the outdoor unit and take pictures of the wiring connections before removing them.

      Jim

  81. morteza says:

    Hi Jim
    My home A/C unit’s fan in normal operation starts sooner than compressor and now sometimes it works normally but sometimes the fan doesn’t start and spinning it doesn’t made it to start and sometime it starts but when the compressor starts the fan stops!
    Can you help me?
    Thank you Jim

    • Jim Plummer says:

      Morteza,

      A failing capacitor or fan motor can be the problem. You can take them to your nearest U-FIX-IT store for free testing. Be sure to disconnect electrical power to the outdoor unit and take pictures of the wiring connections before removing them.

      Jim

  82. Troy Bayer says:

    I just moved into a new home at end of March. Shut off my A/C unit when I went on vacation. Returned home to 90 degrees (temp jumped 30 degrees in NJ in a week). Switched to cool on the thermostat and air compressor fan not spinning. Air is being pushed out through vents. I switched from Auto to On several times to see if that would trigger it, but it didn’t. Any suggestions?

    • Jim Plummer says:

      Troy,

      If your compressor is not running, then take your contactor to your nearest U-FIX-IT store for free testing. Be sure to disconnect electrical power to the outdoor unit and to the indoor unit before removing the contactor. Don’t forget to take pictures of the wiring connections.

      If your compressor is running then take the capacitor and motor to your nearest U-FIX-IT for free testing.

      Jim

  83. Zahoor says:

    Hi,
    Need help with my Lennox A/C Unit, not running (Outside units fan is not running).

    I have the thermostat set set at 70 degree, set at cool, the fan blowing air through the duck, but regular air, NOT cool air. While I went outside i see the outside Lennox A/C unit is not operating, no sound and the fan is not working.

    I do not see any switch that may be tripped. I am sure this could be a simple work, or may need a technician’s inspection. Do you know what that might be?

    Thank you.
    Zahoor

    • Jim Plummer says:

      Zahoor,

      If your compressor is not running, then take your contactor to your nearest U-FIX-IT store for free testing. Be sure to disconnect electrical power to the outdoor unit and to the indoor unit before removing the contactor. Don’t forget to take pictures of the wiring connections.

      If your compressor is running then take the capacitor and motor to your nearest U-FIX-IT for free testing.

      Jim

  84. Wade P. says:

    My outside motor wasn’t running. I gave it a push with a long screwdriver, and it took off spinning. Cool air started entering the house again. When the house cooled, and the unit kicked off, it wouldn’t restart. I replaced my run capacitor, then the motor ran slower, and stopped. Next, I replaced the motor, and added the new 5uF capacitor that came with the motor. At first it ran in reverse. I swapped the connection and it wouldn’t run. Frustrated, I went inside. About 5 minutes later, I went out to trouble shoot and the motor was running in the proper direction. New problem: no cold air in the house, now. It’s just blowing warm air. I’m all tapped out on knowledge. HELP! 🙂

    • Jim Plummer says:

      Wade,

      When a new problem appears while accomplishing a repair, I recommend reviewing everything that has been changed paying special attention to all wiring connections. One or more of the compressor wires may have be disconnected or plugged into the wrong place. Compare the compressor wiring to the wiring diagram on the outdoor unit. The compressor is probably still OK, sounds like it is not getting the power it requires to operate.

      Jim

  85. Daniel Pochmara says:

    My condenser unit outside is not coming on. If I use a dowel to spin the fan, it starts spinning under power. I can hear the condenser trying to come on every 20 seconds or so, but will not come on.

    • Jim Plummer says:

      Daniel,

      The fan motor needs to be replaced when it no longer starts without a spin up. The compressor is turned off by an internal safety when the fan motor is not running to prevent permanent damage from overheating. The compressor will resume normal operation after the fan motor is replaced if the internal safety was successful in preventing permanent damage.

      Jim

      • Gerardo says:

        I will like to know why went I turn my ac only the outside unit work but the furnace don’t

        • Jim Plummer says:

          Gerardo,

          A failed capacitor or fan motor can be the problem. You can take them to your nearest U-FIX-IT store for free testing. Be sure to disconnect electrical power to the outdoor unit and take pictures of the wiring connections before removing them.

          Jim

  86. Becky says:

    We have a GE window A/C unit model# AEW12AQW1. Last summer, it started pouring water like crazy. We kept the filter clean and we double checked the tilt of the unit. It has more than 1/4 inch tilt to the outside. It was so hot last summer and we needed the A/C, so we just kept a bucket beneath it to collect the water. This season, we cleaned it out and tested it and the compressor is not kicking in. We have turned the temperature down to nearly 60 and still the compressor will not come on. Any suggestions on what we can do to fix it ourselves or do we just need to purchase another unit? Thanks!

    • Jim Plummer says:

      Becky,

      You can take the capacitor to your nearest U-FIX-IT store for free testing. A multi-meter can be used to check for proper voltage going to the compressor. Call your nearest U-FIX-IT store for help personalized help in trouble shooting.

      Jim

  87. ed says:

    hi jim.

    i have split type AC and the indoor was doing fine…but the outdoor unit has the problem…only the fan is working…the compressor showing high ampere and goes to shut off.what should i do?

    thanks

    • Jim Plummer says:

      Ed,

      Make certain both the indoor coil and the outdoor coil are clean. Look for anything that could restrict airflow across either coil. Air filters should be clean and vents open. Closed off rooms can restrict airflow across the indoor coil. Any of these things can cause an increased load on the compressor.

      Jim

    • ed says:

      i already change the capacitor but still compressor not work…maybe it will cause also for gas charge?

      • Jim Plummer says:

        Ed,

        Loss of refrigerant can cause your symptom. I recommend eliminating everything else first. Charging an a/c system is best left to people have the equipment and expertise to do it correctly. Adding refrigerant because you think it might need it can end up costing more than you save. Any system that is low on refrigerant has a leak that should be located and repaired.

        Jim

  88. Nii Armah says:

    Please i have a split Ac which the fan of the outdoor spins but the compressor doesnt shoot,can it be that the outdoor unit is different from the indoor?

    • Jim Plummer says:

      Nii,

      When the fan motor runs, but the compressor does not you are down to very few options. Start with testing the capacitor and looking at the wires to make sure there is a good connection to the compressor. Wires can burn off at the compressor and there are repair kits for that. You may take your capacitor to the nearest U-FIX-IT store for free testing. If the capacitor and the wiring are good, you can try a hard start to see if it will give you additional life from the compressor. If all the above efforts fail, your replacing the compressor or the outside unit is the most likely solution.

      Jim

  89. Adrian says:

    Hi Jim,
    My AC unit outside won’t come on. Voltage is coming to the contactor but not coming out. Also, I don’t read 24 volts from the low voltage side. I had the capacitor tested and it is fine as well. What do I do from this point forward?

    Adrian

    • Jim Plummer says:

      Adrian,

      Your contactor must have 24 volts to actuate. Go inside to the furnace (air handler) and check for 24 volts there. Most indoor units have a wiring diagram on one of the panels that can provide a road map for diagnosing the problem. Trace the 24 volts from the transformer through the thermostat back to the outdoor unit.

      Jim

  90. zaw says:

    Needs advice for my payne heat pump please , My payne outdoor fan is not spinning and not heat coming out from vent . I put new capacitor and new defrost board but still not spinning, But if i push the button on the contactor , fan is spinning , what is that mean? need new contactor or any idea ?
    thanks for reply
    Z

    • Jim Plummer says:

      Zaw,

      It sounds like either a bad contactor or 24 volts is not being sent to the contactor by the system to activate it. Use a volt meter to check for 24 volts on the control leads when the system is calling for the outdoor unit to run. If you have 24 volts then the contactor is bad. You can take the contactor to the closet U-FIX-IT store for free testing or call if you need help confirming your diagnosis.

      Jim

  91. Chels says:

    If the outside unit fan had stopped working, but air was still blowing in the vents. Is it safe to use the heat?

    • Jim Plummer says:

      Chels,

      In most systems, this would be safe. If it is a heat pump, I would cut the power to the outside unit and set the thermostat to emergency heat until you can repair it.

      Jim

  92. Gena Lashley says:

    Hello,

    Our Ream unit will blow air inside, but we noticed (as the thermostat temperature kept creeping higher) that the outdoor fan was not blowing. We are not well versed in technical things, what should we do. We have flipped the breakers already.
    Thanks!

  93. Danilo Samano says:

    hi.., have an Split type AC with inverter.., and i have a problem because it just begun not to work properly.., the indoor unit is working fine however the outdoor unit is not functioning the Fan nor the compressor is turning on.., can anyone help me? thnxz in advance

  94. david says:

    Hi, we had our ac running fine until a stick became stuck in the grill where the fan is and the fan was cutting in to the stick with bad noise!. then the fan would not turn again but sounds like everything else is doing its job… what should i check first please? motor burn out? or possible cut of fuse inside? thanks for your help

  95. PJ Thompson says:

    Hey… my ac has been leaking from the drain pan… so I have been draining it manually every night… last night I forgot and went to bed… I came home from work today and the inside unit nor the outside unit are working… I checked the breaker, the power box outside, and the power button on the inside unit.. they were all still on. I unclogged the drain and was hoping it would work…. still not coming on…. help… please….

  96. Dave Williams says:

    Need help!
    Until here recently, say a couple days ago, our AC unit has been working perfectly. This is a Grandaire unit which was completely replaced no more than 6 months ago since the Goodman unit went out. The AC didn’t seem to be cooling very well and would never get below 80 degrees. Here in AZ it’s been around 90-100 outside and even at 80 it was feeling a bit warm. The air coming out of the inside vents was around 85 degrees, taken with a digital meter. Checked the filters and they were clean, turned unit off thinking the coils may have been frozen. After about an hour I turned the unit back on and the air coming out of the vents was at 65 degrees. Thinking the problem was fixed I continued on with my day. However later on we had the same thing happen, AC wasn’t cooling and the air out of the vents was warm. Did a little more investigating and found out that the outside unit’s fan wasn’t turning. Checked with a wooden stick to see if it would turn and it turned freely but would start going even though the compressor was going to town. Took the temperature of the compressor and it was around 150 degrees. Pulled the outside disconnect to shut it down in order to keep it from getting damaged. After a few hours of letting it cool down I powered it back up and the compressor and fan started back up as normal. However after a few more hours the fan had stopped again and there was a venting noise coming from the location of the compressor. Although I couldn’t see anything venting but could just hear the noise. Shut the unit down and scratching head now. Not exactly sure where to troubleshoot now. I would think if it was the run capacitor then the fan wouldn’t run, ever. If it was the fan motor itself I would think it wouldn’t ever run there either.

    Not sure what to do seeings how this is basically a brand new unit being only 6 months old.

    • Chris says:

      Very similar situation here. The HVAC guys just left 30 minutes ago after having installed a new motor and capacitor and adding R22. AC was running for 20-30 minutes and the fan just stopped. Still spins freely.

  97. Jay Riddle says:

    Help! I just replaced my a/c unit last year. I came home today and heard the outside unit “shorting” out. It is a continuous clicking noise that sounds like a circuit shorting out. The outside fan is not turning. Any ideas?

    • Jim Plummer says:

      Jay,

      If this was my unit, I would turn the power off to the outside unit and then feel the motor (carefully) and compressor to see how hot they are to the touch. After everything cools down, I would reapply the power and see what comes on. The fan motor or capacitor is the most common failure. I would be expecting the fan motor and compressor to come on and appear to run normally. A clamp on amp meter can show immediately if your motor or compressor has a higher than normal amp draw. If your motor is bad, it will slow up and/or stop when it overheats. After a time the compressor internal safety will shut down as well. A clamp on amp meter can show immediately if your motor or compressor has a higher than normal amp draw. You can take your motor and capacitor to your nearest U-FIX-IT store for free testing or call them if you have questions.

      Jim

  98. Tracy says:

    Jim,

    Our problem is that the fan and compressor will not come on all the time. Neither one runs without the other and when they do kick in they run great (no unusual noises) until the set temperature is reached (they have never stopped before reaching set temp). After that we have to wait hours (10-12) for it to come back on again. We have replaced the thermostat, capacitor, and contactor. Of note, when it does not kick in there is absolutely no noise whatsoever. The fan turns easily and turning does not “jump start” it. When it is running there does not seem to be any overheating of the outside unit. Any other suggestions?

    • Jim Plummer says:

      Tracy,

      A multi-meter for reading voltage is absolutely necessary to continue the trouble shooting process from here. There is usually a wiring diagram on the inside of one of the panels on the outdoor unit. When the outdoor unit stops, I would make my first measurement where the 220 volt power is coming into the unit. If I have 220 volts there I would follow the wiring diagram toward the motor and the compressor to see if there is any point where I lose the voltage. If there is not 220 volts at the first measurement, then I would work back toward the main breaker box for the house to locate where I voltage reappears.

      Jim

  99. Debby Cass says:

    Our Payne air conditioner outdoor unit is not running. The indoor fan is running and I can hear the outdoor unit clicking, as it is trying to turn on.

    How do I disconnect the power to the outside unit, so it doesn’t burn up trying to turn on. We are using the Fan indoors. Thank you

    • Jim Plummer says:

      Debby,

      Most outdoor units have a shutoff on the wall next to the unit. Another way is to look in your main breaker box for the house and turn off the breakers for the the outdoor unit.

      Jim

  100. Nghi says:

    Dear Jim,

    My A/C unit will work but shuts off after ~30 minutes. It doesn’t trip the breaker but the only way for the unit to work again is to reset the breaker. The capacitor and contactor has been replaced and the coils cleaned. The GE 5KCP39DG fan motor is ~75*F before starting it up and gets to ~100*F at time of shutting off. I’m not sure what the temperature limitis before the thermo protector kicks in. What do you think my issue is?

    • Jim Plummer says:

      Nghi,

      You have replaced the two items (capacitor & contactor) that are common to both the compressor and the fan motor. That leaves power. If this was my a/c unit I would start with measuring the voltage coming into the the outdoor unit while the unit is not running (before you reset the breaker). If you do not have 220 volts, then the breaker has tripped even though it does not appear that way. I would then use a clamp on ammeter to measure the amp draw of the motor and the amp draw of the compressor. Whichever reading (motor or compressor) spikes upward before the unit shuts down is the bad unit. If there is no spike in the amp draw, the breaker may be bad.

      Jim

      • Nghi Nguyen says:

        Dear Jim, here’s what I found so far. I’ve replaced the run cap with the wrong one since there was no label on the old one. I am currently waiting for the correct run cap to come in. My unit needs a 370v 55/3mfd run cap while I wrongfully installed a 370v 40/3mfd. I had a clamp meter to the wires that draw power and the compressor reads ~16A and the fan motor reads 0.8A. The label says the compressors rated load current is 22.1A and the fan is 1.1A. The A/C does get 240v before the breaker trips usually after ~15 minutes. I’ve tried to do what you’ve said before and watch for an amp spike before it trips but I haven’t been able to get it to trip even after running the unit for 40 minutes so I gave up on that since the sun is down now. With all these bits of info, what can you tell me. hopefully you can point me in the right direction. Thanks in advance Jim.

      • Nghi says:

        Can my AC unit shit off and trip the breaker due to putting in a 370v 40/3mfd run cap when it originally had a 370v 55/3mfd run cap?

  101. Mary says:

    Hi Jim,
    I have a fairly new Goodman heat pump, about 4 years old. When I bought my house 3 years ago, we noticed when the electricity went out and came back on the outdoor unit would make a loud noise and nothing would come through the vents (this happens in the winter and summer). The fan still spins outside while making the loud noise. We have to turn the thermostat off for a couple days and then turn it back on and it works fine. Almost every part has been replaced in the outdoor unit over the past 3 years but it still does it. Do you have any clue what it could be? I’m thinking it may be something electrical at this point or maybe needs a new thermostat?

    • Jim Plummer says:

      Mary,

      Compressors do not do well when the electrical power is cycled off and on. Most of the negative things that happen as a result of short cycling can be prevented by installing a time delay relay. This is an electrical device that detects the loss of power to the condenser and then prevents the unit from coming back on until a preset time passes. The time delay gives the a/c system time for the internal (freon) pressures to equalize which will make it much easier for the compressor to start. Some digital thermostats have time delays built in to their circuitry. While there is no guarantee a time delay will help our situation, it is what I would do if the system was mine.

      Jim

  102. Kinco says:

    Hello Jim,
    I’ve a GOODMAN GSH130301AB model heat pump. The unit was working fine since 2007.In winter 2013 my outdoor fan broke and my wife still ran the heating system not realizing what was going on and the house literally didn’t warm up much. Very little hot air was coming out of indoor vent but no pushed air and unfortunately i couldn’t hep her much since i was deployed. Back in APR 2014 i changed capacitor 5/40/370 (same configuration i found inside) and everything worked fine until day before yesterday. Then i read the manual and found out that original capacitor came with the system doesn’t match with the manual. Manual instructed me to use 5/40/440. This time i followed manual and changed capacitor and 25 amp contactor as well. But still the fan doesn’t kick. The only thing i hear a minor click when i turn on thermostat. The only thing i noticed prior to this issue was the fan was making some weird noise the day day before it was completely dead. Please help. Thank you for your earliest attention regarding this matter.

    • Jim Plummer says:

      Kinco,

      The 440/5 is actually a better choice than the 370/5. The 440 volt is telling you the capacitor is the “heavy duty” version. If the compressor is running, then your symptoms are pointing toward a bad fan motor. A meter can be used to check the continuity of the motor windings and to check for a short to the casing. You can take both the motor and the capacitor to the nearest U-FIX-IT store for free testing or call for assistance.

      Jim

  103. Jerrod says:

    We purchased a house last year, had the ac unit recharged a few months back, and a week later the fan quit working, since then I have replaced the fan motor, the dual capacitor (original was 40/4, replaced with 40/5) and the start capacitor… The fan still won’t turn, can you help? The compressor turns in, but the fan doesn’t spin???

    • Jim Plummer says:

      Jerrod,

      Check your new fan motor to see that it needs the 5 micro-farad capacitor that you installed (the 5 of the 40/5). Replacement motors often require a different size capacitor than the original and the size they need is usually printed on the label of the motor. If the size is correct, then look at the wiring to make sure you have all the wires plugged correctly. If wiring and the capacitor are correct, then you may have a defective motor or capacitor. You can take your motor and capacitor to the nearest U-FIX-IT store for free testing.

      Jim

      • Jerrod says:

        Jim-

        On the motor it states cap 5 mfd 370 vac the capacitor I have is 440/5, could it be that it is to large? Is there a way to test fan without capacitor to see if it works?

        • Jim Plummer says:

          Jerrod,

          The 440/5 is actually a better choice than the 370/5. The 440 volt is telling you the capacitor is the “heavy duty” version. A good capacitor is required to run the motor. A meter can be used to check the continuity of the motor windings and to check for a short to the casing. The capacitor can be tested by itself with the appropriate meter. You can take them both to the nearest U-FIX-IT store for free testing or call for assistance.

          Jim

  104. Drew Watson says:

    Hi Jim,

    I can jump start my ac fan outside fan with a stick but it turns off after about ten minutes and the motor is hot (the air it blows in the house isn’t even cold – nor are the Freon pipes outside). The fan/motor then clicks like it’s trying to restart itself and after a few minutes and I can jump start it again. Bad motor right?

    Is it ok to leave the interior blower on to keep air circulating in the house with the outside fan off? I turned the power box outside to off to keep the motor from overheating.

    Thanks for any input!

    Drew

    • Jim Plummer says:

      Drew,

      Yes, it is OK to run the indoor fan motor while you have the power cut off to the outdoor unit. You have the classic symptoms of a bad outdoor fan motor. I would replace the outdoor fan motor and capacitor if it was my system.

      Jim

  105. Chad says:

    Hello,
    Need some help! My outside ac unit not working. At first the fan went out and i replaced the capasitor. Worked fine for a few weeks. Now the fan is not working again and theres a loud noise like hussing or a loud vacume cleaner sound. What should I check into? The capasitor that i got was not the exact one that was in the unit at first. The store said it would be fine. The micro fairhats were a little more. Let me know.. thanks

    • Jim Plummer says:

      Chad,

      Rule of thumb on microfarads is you must stay within plus or minus 10% of the needed value. The incorrect capacitor can cause premature failure of the motor. Also a bad motor can cause a capacitor to fail and a bad capacitor can cause a motor to fail. It sounds like the motor and capacitor need to be replaced. You can take them to the nearest U-FIX-IT store for free testing.

      Jim

  106. JS says:

    Jim,
    I’m fairly descent at diagnostics and troubleshooting but please forgive me for my basic question here. Over the weekend, we lost power several times. I’m sure we also had voltage spikes because of it. Regardless, we lost cooling some how. I’ve reset the indoor thermostat to call for cooling. I can see the fan running as normal on the outdoor unit. My question is, how do you know if the compressor is running? I don’t see any moving parts and if it were running it would be muffled by the fan. Would it be obvious and loud enough to hear? I’ve listened for quite a while and have heard nothing other than the fan.
    The unit is a Goodman and fairly small, it is also old. However we just recharged the system last week and it was working very well.

    Thank you, I appreciate your time.

    • Jim Plummer says:

      JS

      The compressor can usually be heard, but sometimes it is so quiet you need to lay your hand on it to know for sure. Be careful as the compressor may be hot (not just warm) if it has cut off due to overheating. Of course, the sure way is to measure the amp draw with a clamp on amp meter. Your last note about recharging the system is a red flag to me. The freon charge is critical to the operation and health of your air conditioning system. A system that is low on freon has a leak that should be located and repaired. Charging a system correctly requires proper equipment and expertise. Charging a system incorrectly or using bad procedures can cause premature compressor failure or substandard performance of the system.

      Jim

  107. Butch says:

    Good Morning Mr. Plummer,
    Last night our air conditioner quit blowing cold air. The fan in the house is blowing room temp. air (about 70-75 degrees. But the fan in the A.C. unit is not running. I can hear a faint hum from the compressor. I can also feel it working- BUT it is pretty warm to the touch,not real HOT just pretty warm. So I turned off the AC breaker as well as the switch outside by the unit & turned off the thermostat. Now what do you suggest I do next? THANKING YOU IN ADVANCE,
    Butch

  108. Shanna says:

    Our A/C fan kicks on and the furnace kicks on to blow the air, but the air is weak and warm not cold. Its been working fine then today started doing this. I dont know what it could be. The coils aren’t even getting cold. We cleaned them off and still nothing

    • Vanessa says:

      Hi Jim,
      I don’t have a comment for Shanna ~ but couldn’t find the comment request info button!

      Anyway, our Outside Fan has stopped and so of course our Central Air-conditioner is not longer working.
      Our neighbor’s friend who is a heating and cooling repairman, looked our situation over and said we honestly need a new furnace. It was a very old furnace.
      I was shocked that nothing short of a furnace replacement would get the C.A. running again.

      I read a lot of the comments and no one seems to mention needing such a big replacement for their C.A. to get running again.

      Can I ask your honest opinion ~ do you think this makes sense that my furnace died and needs to be replaced. I am a single mom . . . need I say more.

      Thank you so much for your help! I sincerely appreciate it!
      Vanessa

    • Jim Plummer says:

      Shanna,

      Your symptoms point toward a compressor that is not running. If you cannot hear or feel the compressor running. You can take the capacitor to your nearest U-FIX-IT store for free testing. If the capacitor is good and the compressor is not starting, it is a bad compressor.

      Jim

  109. Thank you for posting. This a great article to read for troubleshooting your ac. I own a small hvac company called Air Medics. I woul definately reccomend this read to some of my clients to take care of basic repairs if they wanted to do it themselves. Thanks for sharing!

  110. Terrance says:

    Hello. Looking for a little help my inside unit and outside unit just stopped working i have a carrier fb4ana018 air handler the a/c and the heat are not working and the fan on is not working i dont have alot of experience in this type of work but i opened the carrier system in the basement and the board hk61ga003 had a burnt mark on it so i replaced it with icm272c board and replaced the transformer but still nothing the icm272 is the replacement for the old board the circuit breaker are on and im still getting nothing. I don’t have a multimeter at this time but i will have one tomorrow please help thank you.

    • Jim Plummer says:

      Terrance,

      The multimeter is a requirement for moving forward. Locate the wiring diagram that is usually attached to one of the access panels of your furnace. The 24 volt system is the right place to look first. Start at the transformer making certain you have 24 volts there and then work your way through the wiring diagram to find where you are losing the 24 volts. Look for a fuse protecting the transformer on the wiring diagram as well. Let me know how things go.

      Jim

  111. Wayne says:

    Hi Jim,

    My AC fan outside isn’t spinning but the air is blowing from the vents inside of the house when AC is on. I tried moving the fan with a stick but to no avail so I replaced the capacitor. The fan would not spin after the replacement and I don’t hear anything from the compressor, so I’m assuming the problem might be with the contactor?

    • Jim Plummer says:

      Wayne,

      If your compressor is still running when the fan motor is not, then the contactor is O.K. and the motor is probably bad. You can take the contactor, capacitor and the motor to the nearest U-FIX-IT for free testing.

      Jim

  112. Branden Putnam says:

    Hi Jim,

    My outside units motor or capacitor went bad we were giving another one for free so instead of replacing the entire thing I just replaced the capacitor and motor. The fan clears it and at first the fan turned on when the thermostat was on, but then it stopped running when I had pushed that button on the contactor. The fan will hum for a second then kick on, after a few min it turns off for a second or two then kicks back on but I have to push the button for it to kick on I left the thermostat on for a lil bit to see if it would but I didn’t want to leave it on for to long.

    • Jim Plummer says:

      Branden,

      As I understand the sequence of events. The outside unit fan motor and capacitor were replaced for a second time when they failed in warranty. When the fan motor fails, it is important to change both the capacitor and the motor together. A bad capacitor can damage a new motor. If this was my unit and the second new motor is now failing to start, I would be making certain the capacitor matches the requirements of the motor and rechecking the wiring. If the capacitor matches and the wiring is correct, then I would verify the fan is positioned correctly in the fan shroud. Finally, I would verify it is the correct motor. Motors will fail prematurely if the motor is not sized correctly.

      Jim

  113. Antonio says:

    Hi Jim,

    I have a one piece unit that will run for about 10 min and shut off. The condenser fan motor, the condenser coil and compressor gets hot to the touch. At first it would trip the breaker that controls them. I have replaced the fan motor, the contactor, the capacitor, and cleaned the condenser and evaporator coils. Now it does the not trip the breaker but stills shuts off when it is hot and come back on when it cools down. What else could it be? Being a new fan, shouldn’t the oil level be good?

    • Jim Plummer says:

      Antonio,

      You did not say if both the fan motor and the compressor are shutting off or just one of the two. It is normal for air conditioning components to be hot to the touch. A compressor can run hotter toward the end of it’s life and cycle off on the internal safety, especially on hot days. The symptoms you gave are not pointing toward anything specific. Call the U-FIX-IT nearest you for additional help in trouble shooting.

      Jim

      Jim

      • Antonio says:

        Replying to my previous comment and your comment, They both will shut off. If the fan is running but not the compressor the fan will run fine. I have checked the amp draw on both the fan and the compressor and the fan reads 2.5 with a RLA of 2.1 but with the compressor, the RLA is 21.8 and at first it will be fine but over time (5 to 10 mins) it moves up to 22.9 and makes a hissing sound as if it was releasing pressure, jump to maybe 32 and then cut off. The microfarad on the compressor is in range with a 48.5 out of 50. The is about 3 years old.

        • Jim Plummer says:

          Antonio,

          The jump in amps and the hissing sounds are pointing toward a compressor or sealed system problem. The sealed system is all of the components that contain freon. Moisture in the sealed system can freeze causing a restriction in the freon passageways which in turn makes it harder for the compressor to do it’s work (hence a rise in amp draw). It is probably time to bring in a qualified technician that has the skills and the tools to troubleshoot and repair the sealed system. No quick and easy solution here.

          Jim

  114. Christopher W Eich says:

    Hi, figured I would give this a shot. My downstairs unit , a 2 ton heatpump split unit. Stopped blowing cold air and started blowing warm, hot air. Called my hvac buddy and we checked the super heat temps, compressor, fan, ect. He changed the blower motor from low too high to be safe, the coils under the house looked great other than the drain pan being a bit clogged. Other than the electric heating strips, which he disconnected just in case, he couldn’t find anything wrong. With the bigger airflow, it does blow well, but it still isn’t cooling, and the temp split between the return and output is almost zero. Compressor and fan are running. Could it be my thermostat? The way it seems to be working now is just pulling could air down my stairs and recycling it.

    • Jim Plummer says:

      Christopher,

      You need to get a new hvac buddy. If everything checked out as you described, you would be cool. Put everything back the way it was and start the troubleshooting process again.

      Jim

  115. Kevin says:

    Jim,
    Can you give some advice please. Our outside unit doesn’t always fire up. the large fan will always spin, but every 15 seconds or so i hear something trying to engage, but won’t. Eventually the unit will start working, usually in the evening. This only seems to happen once every 2 to 3 weeks, but when it does our house heats up badly. Thanks for any suggestions. Also if you have an idea as to how much a repair on this may cost me. I understand you are not here and can’t know for sure what is going on. Thanks so much.

    • Jim Plummer says:

      Kevin,

      Test your capacitor and replace if necessary. You can get it tested free at your nearest U-FIX-IT. Installing a hard start can help compensate for power variations from the electric company. If those two items do not change your symptoms and you are confident the power company is delivering good power, then it is likely your compressor is beginning to fail.

      I hope the capacitor and/or the hard start fixes the problem.

      Jim

  116. Tami says:

    Hi Jim-
    I used to be able to assist on repairs to outside units as our old business partners used to specialize in a/c repairs & unit replacements. I am terrible, however, with a multimeter. Our capacitor was starting to go bad & recently when unit kicked on fan stuck as it had a few times before but as I went outside to unstuck the blades, the fan began turning freely with no resistance. After about a week,the fan blades are now completely froze. After running approximately 15mins, is when fan stuck for a few seconds & then broke free & would only turn loosely. I live in Florida & became disabled at work. My husband is a heart recipient. A couple here locally just died from same situation that we’re in. Very limited income to work with now as well spent our savings repairing hurricane & flooding damage. Can you give me some helpful hints to try & fix the problem on my own? No immediate family & friends we know in our area.

    • Jim Plummer says:

      Tami,

      Your description points toward a bad fan motor. If it was mine, I would replace the motor and the capacitor.

      Jim

      • Tami says:

        Exactly as I thought; unit bought at that time is a Thermal Zone but checked the other day & saw the fan motor was a GE. Are they hard to wire back in? I seem to remember seeing the wiring running through pvc like tubing. Thank you so very much for your analysis & your insight. If not too hard to fix, might do both myself. Lol. Thank you again.

        • Jim Plummer says:

          Tami,

          Replacing the fan motor is not rocket science. Take pictures of wiring connections as you start. Take your old motor to the nearest U-FIX-IT Store. We will match it and configure the new motor for your installation. Our explanation of wiring the new motor will make it easy to get it right. Call anytime during the process if you have any questions.

          Jim

  117. Vincent says:

    My A/C compressor start and stop every 1min but the fan keeps working, the temperature is set to the lowest 17degree, I have change the capacitor but it keeps doing the same way. Please how can I fix the problem.

    • Jim Plummer says:

      Vincent,

      Measure your voltage going to the compressor while the compressor is cycling. If the power is not cycling on and off, then your compressor is failing.

      Jim

  118. oscar says:

    Hey jim..my compressor unit is not working. Unit inside is blowing air working fine but ofcourse not cold air. It was working fine but last night I turned it on..compressor went on fine room was getting cold..but then compresser stopped working, and the room didn’t reach the temperature. And today I tried turning it on the compressor wouldn’t come on. I turned the breaker off then back on(outside switch), turned the ac on and after about idk 2 min the compressor came on but then again same thing room was getting cold then compressor went off again, room didn’t reach the temperature set on remote..and compressor won’t come back on…tried switching the breaker off and on again but this time compressor wont come on

    what specifically could be the problem ? Capacitor? Thnks for your time

  119. Cathy says:

    My a/c was working fine today and then I noticed the air was getting warm inside. I went to check the a/c vents, and no air blowing out. Although I could hear/feel air down below the vents a ways. I checked the unit outside, and compressor/motor and fan was working fine. What would make the cool air stop coming thru the vents? It was 100+ today. The unit had been on several hours working okay earlier. Then the next day, I turned the A/C on and air came up thru the vents, but not blowing out that well. Please help! Thank you for your time.

    • Jim Plummer says:

      Cathy,

      There are two possibilities when air is not flowing from the vents properly. 1st the motor is not turning at the proper speed, second there is something in the system that is blocking or restricting air flow. To check for an air flow restriction start with making certain the filter is clean and all of the vents are open in all of the rooms are open. A system cannot operate properly when some rooms are closed off. Inspect the indoor coil to make certain is is clean and free of ice. If you do not find anything that appears to be restricting the air flow, then look to the motor. You can take your motor and capacitor to the nearest U-FIX-IT store for free testing.

      Jim

  120. JoE D says:

    Hi Jim,
    My A/C Condenser fan motor just went out. Bought new motor and cap now the motor gets hot fast about 30 minute and shuts off. I just installed the blades where they cleared the condenser. I think the blade adjustment might be the problem. the location of the blade will determine how hard the motor will work Correct?. should I lower or rise the blades.
    If the blades location is not the problem what do think?
    Thanks for your help.
    Best Regards,

    • Jim Plummer says:

      Joe,

      The location of the fan blade could be the problem. It is critical the blade is located in the same position in the fan shroud that it was with the old motor. The shroud is the circular hole that is just barely larger than the fan blade. Also check to make sure the motor is turning the correct direction to blow air out the top of the outdoor unit.

      Jim

  121. Tim savage says:

    Outside unit freezing up all the way to the a coil. I have replaced fan motor and blade on outside unit cleaned coils inside and outside replaced furnace filter also had some coolant added to unit still freezing. Any help would be greatly appreciated kids are starting to melt in this hot house.

    • Jim Plummer says:

      Tim,

      Adding coolant is a red flag to me. The only reason you would need additional coolant would be a leak. When adding coolant was superheat measured to insure a proper charge? Leaks need to be found and patched. If there is any question that moisture may have entered the sealed system, then the system should be evacuated and recharged. Troubleshooting an a/c system depends on knowing the system is charged correctly and knowing there is no moisture in the system.

      Jim

  122. Tracy E. says:

    The outside unit of my A/C will not kick in. Inside unit seems to work fine blowing air. I have changed the capacitor and when we restored power it kicked right in. However, once the house cooled to set temperature and was ready to cycle back on, the outside unit once again failed. Just to try we turned off the A/C breaker and when we turned it back on the outside unit kicked in. No unusual noises at all. Could it be the contactor? Fan does not start, even with stick test but it does turn freely with no noise.

    • Jim Plummer says:

      Tracy,
      The next time the unit stops, check to see if the compressor is still running and if the motor is hot to the touch. As motors age they run hotter and hotter until the internal safety cuts power to the motor. When they cool down, the motor can be restarted. When the fan motor stops running the compressor will overheat and it’s internal safety will cut it off also. Your symptoms are not pointing toward a contactor.

      Jim

    • Tracy E. says:

      We tried the breaker method later on last night and it failed to work. However, this morning we turned the thermostat down and compressor and fan kicked in. It’s almost like it needs a “rest”. This has happened several times over the last few days. Still thinking maybe the contactor is getting stuck?

  123. Jon says:

    I’ve got a real head scratcher here….My outside condenser fan stopped working .Before this happened it seem like the air blowing out the registers was not that cold. I cleaned the coils( as they where filthy and looked like they where wear’n a fur coat lol) So after the clean the condenser made an odd sound(hard to describe not very loud or high pitch but different than the original sound) . Then the fan stopped working. I replaced the Fan motor and capacitor(thinking that should be it) well no such luck. I checked the contactor and it seems to be getting the proper current/voltage in fact everything seems to be getting the proper current. I rechecked the wires and everything is where it needs to be connected. every time I try and run it the compressor sounds like it wants to cycle but nothing??? any thoughts????

  124. Adam says:

    A/C stopped working a few days ago. I checked the fuses in the disconnect with a meter, and both were blown. Replaced the fuses, and they blew immediately. Called a “tech” that we were told we had to use by our home warranty. He put in new fuses, and they still immediately blew. He then hardwired directly from the incoming 220V to the unit, and it blew the 100A house breaker. He then said there is not enough power to diagnose the problem, and said an electrician needs to look at it. This guy has no idea what he’s doing…

    I turned off all the power to the unit, unhooked the wires leading to the compressor, and checked for continuity with my meter. There was continuity between C & R, C & S, and R & S so I’m guessing the compressor is ok. I then did the same to the fan. There was continuity between C&R, C&S, but not S&R so this leads me to believe the fan motor is bad, correct? I unhooked the fan completely from the system, installed the fuses, and they still blew. I’ll try checking voltage at the contactor “out” tonight. When unhooking everything from the contactor except the coil, no fuses blew and the contactor pulled in. Any other thoughts on how to diagnose or what to look for? I planned on hooking things up one at a time and checking fuses until they blew. Will also get a capacitance meter and check capacitor tonight.

    • Jim Plummer says:

      Adam,

      I imagine you found your problem component through your elimination process if you did not run out of fuses. It appears that you have a short to ground in your capacitor, your compressor or your motor. You can check for that by measuring continuity between the terminals and the case of the component.

      Jim

  125. diane says:

    Unit is 18 years old….fan and condessor not working blows air thru vents but not cold. Has it serviced, worked for couple hours and quit again, put more money in it or time to get new one?

    • Jim Plummer says:

      Diane,

      If it was mine, I would upgrade to the newer equipment and higher inefficiencies if the problem is in the compressor, or if it involves a freon leak for sure. Other problems are less expensive, but you have already received more service from your system than most people do.

      Jim

  126. Mimi says:

    Hi,

    Our ac has been having a problem of not blowing out cold air. The system will be fine, and then stop blowing cold air. The unit outside continues to run and the fan continues to turn. So air continues to be blown out but its not cold. My brother decided to reset the unit located in the attic, and it started working again and blowing cold air. But after a day it stopped blowing cold air. We did this three more times and had the same results. The filter isn’t dirty and from what I can tell, the issue is not freon since ice hasn’t been forming on the outside unit. We were hoping to try to find the problem before paying a technician to come out.

    • Jim Plummer says:

      Mimi,

      Your symptoms could be caused by an aging blower motor that is overheating and kicking out on the internal heat overload protector. You can take your motor and capacitor to your nearest U-FIX-IT store for free testing.

      Jim

  127. Allison Brantley-pruitt says:

    Jim, our unit was work just fine yesterday, then last night it started blowing warm air. The unit outside isn’t making a sound, what could this be.

    • Jim Plummer says:

      Allison,

      Please refer back to the Repair Tips entitled “Air Conditioner Not Cooling- Outdoor Unit Not Running” for step by step help. For additional help you can call or come by the nearest U-FIX-IT store.

      Jim

  128. Angelo says:

    Hi Jim thanks for help.
    My AC system is around 8 years old, built with the house and two units for upstairs and downstairs.
    Downstairs is cooling perfect but upstairs is not cooling When I turn on Thermostat click as normal & I set for 70 auto but room is not cooling it is hot temperature indicates RT 85.
    Outside temperature was around high 80th so not cooling at all, and outside the fun both is running & the non cooling blowing hot around the fun, but the cooling fun which is working is blowing cool air around the fun too & near the hose of the non cooling fun a little condensed water at the end.
    I had changed both filters recently but never had serviced the system because used to work perfectly cooling.
    Generally I don’t have any detailed knowledge about the AC system.
    Tnx

    • Jim Plummer says:

      Angelo,

      The symptoms you describe are not giving me enough to be able to offer any assistance. Try working through the trouble shooting steps again and then describe what is going on with just the system that is not working.

      Jim

  129. Rebecca says:

    Actually, I just found it. It does not appear to be damaged, bowed out, or otherwise in bad shape. No foul odor. The fan does NOT come on when I spin it. Could that be a symptom of needing to be charged? Or am I about to get depressed because it is yet another fan motor?

  130. Rebecca says:

    I’m often gone a few days at a time, but I live in Texas, so I have to leave my a/c on for my cats. Last time I came home my indoor coils were frozen solid. Fan had stopped. I replaced the indoor motor & capacitor & cleaned 10 years’ worth of scum off the fan & housing. It runs very smoothly & quietly now. Last year I had the outdoor unit replaced when my compressor went bad. When I turned my unit back on this time, now the outside unit will not kick on, though it hums quietly). I’ve looked at the connector (it appears clean & in good shape), and I was wondering if the exterior unit has a separate capacitor. If so, where is it located? The unit will not come on when I spin the fan.

  131. Alex says:

    Hello, last night my compressor stopped running. I could hear a loud buzzing and the unit was even vibrating as if it was running but no fan movement. After powering it all down in hopes of it resetting it’s still not working. Any thoughts? Thanks in advance.

  132. Stephen says:

    Jim,

    We have a very unique issue. We travel in a ministry group on a 1996 Prevost Entertainer Coach. We bough the bus a few months back. Since then we’ve had numerous issues with one of our house AC units. It’s considered a basement unit I think. But, I’m told it’s setup just like a house unit. We have two units in all, and one works great!

    So, about the other one! We’ve had a few licensed repair people work on this and not figure it out. Basically, it will work perfectly for a day or two. Then, the compressor kicks out because it stops blowing cool air. Then the fan runs but the air is not cool. I want to preface this with the fact that we only travel on weekends. So, the AC is set to very high temperatures during none use… Like 80 or 85 to keep the inside decent.

    So, first they replaced the fan because it stopped working. The air worked fine for a week or two. Then, we replaced the thermostat because we were told to do so. It worked for a few days. Then, another guy said we had too much freon in it. That helped for a few days. Then, we had a friend replace all the compasitors on that unit. It helped for a few days. Then, we checked the freon levels. He first said there wasn’t enough. He added more. The unit overheated and then when he measured it it said too much. He wasn’t thinking about it being hot and let some freon back in the container. Then, he checked it again when it was cool and it said it was low. After that, it worked great for a few days. His thinking was that the fan wasn’t working enough to cool the unit. And, he was checking the unit with the cover off. For some reason, the unit seemed to overheat with the cover off. Then, we took the fan off the other matching unit and used it for a few days on the troubled unit. It messed up again!

    As you can tell, no one has a clue what’s wrong with this unit. Our AC friend has been real patient. He came in after he heard all the stuff they tried. He’s at least doing one thing at a time and testing it out. But, we really are losing our minds with this thing. Someone suggested a freon leak. But, I don’t see how that’s possible because when it works, it’ll cool that bus to 59 degrees! Then, it just quits. Obviously we don’t put it on 59 lol. Another suggested that the compressor is bad, But again, it works at times. And sometimes for days. Hot days in Atlanta heat! Then it quits!

    Are there any suggestions you would have? First thing I told our owner is to let one person stick with it and figure it out. It’s just so hard to test because it if you do one thing to it, it might randomly start working again. I’ve even suspected something in wiring or electrical? We did confirm that the compressor is kicking off when this happens by hooking gauges to it.

    This thing has confused 3 professional AC men!

    • Jim Plummer says:

      Stephen,

      If this was my unit, I would start with making a thorough check for a freon leak and fix the leak if there is one. Then I would pull a vacuum until it shows a vacuum in the micron range. Then weigh in the freon charge according to the factory specification. Once that step is complete the freon charge is eliminated as a consideration and the possibility of moisture inside the sealed system is eliminated. Then the troubleshooting should be able to proceed in a more productive fashion.

      In looking for a technician to solve your problem, look until you find one the owns (and uses) a micron meter and who knows what you are talking about when you say want the charge weighed in according to the factory specs. You may want to start by calling the factory for your a/c unit and seeing who they recommend in your area. The principles of operation of your unit are the same as any a/c unit, but there are going to be things about it that are unique to the application that most a/c men would not have any reason to know.

      You are right – too many cooks in the kitchen. The unit likely has at least one additional problem that has been added during the repair process. One qualified experienced tech on your unit can no doubt, work through the multiple problems.

      Jim

  133. soom Xiong says:

    Earlier my son turned off the air conditioner. Now it won’t work. The outside unit is not spinning and I am not hearing anything. I turn it off and back on but so nothing. What else can I do?

  134. Becky says:

    Hi! I found water had leaked to my bathroom carpet and realized the pan had overflowed. I poured bleach down the pipe and (thank goodness) it cleared up and dried up. BUT, the very next day, it went up to 88 inside the house (when the temp was set at 78). The outside fan was running, but when the “cool” setting was initiated, it would click on for 2 seconds and then shut off. Somebody checked it and said the compressor was locking up and recommended I get pricing for a complete new unit. I can’t afford that and am wondering if it could be another part. In the meantime, I borrowed a window unit from a dear friend so I don’t melt!
    1 – if it’s another part, which could it be?
    2 – he had shut down the whole outside unit. Is it safe to have the fan on outside but keep the “cool” setting off so the compressor doesn’t try to run?
    Thank you so much!

    • Jim Plummer says:

      Becky,

      A hard start kit will sometimes give additional life to an old compressor by helping it to start, but there are no guarantees that it will work. If it does start the compressor, there is no way to know how much longer the compressor will last.

      There is no benefit for you to have the outside fan motor running without a compressor running. Better to leave the power off to the outdoor unit and save the electricity. Running the indoor fan may help keep you more comfortable by circulating the air.

      Jim

  135. Darrin says:

    A couple weeks ago my AC stopped blowing cold air on a very hot day. The fan on the compressor outside was still turning during this time. I called a repair person but they couldn’t get there until the following day. That night I tried turning it back on and it worked fine ever since. The repair person checked my pressure and said it was good. Today though the same thing happened. The AC vents blow warm air.

    I have read here about the fan motor going bad but it is still turning during this time so could that still be it? It’s like the compressor isn’t working during this time even though the fan on it is.

    Any guidance as to what I could try is greatly appreciated.

    • sarina s. says:

      hi darrin & jim. I have the same problem…on moderately to very hot days, the fan on top of the outdoor compressor unit spins, but the compressor motor does not click on. vents inside the house blow hot air that smells different – not bad or stinky, just not the same as the cooled air (a stale/attic-y smell?). like I said, this seems to only happen in afternoon heat. the unit is on the south side of the house with no shade. I am in Los Angeles valley area so it does get very hot. hvac techs (3) and electricians (2) all say power readings look normal and no one can tell me what’s wrong. last perplexing detail is that the unit works great at night time! since it’s kind of an intermittent problem it’s hard to catch it “in the act” when the techs are here. I read your posts and I’m wondering could I really only need a new fan motor and capacitor or do I need a new compressor? I’m to the point where I will just instruct the techs to replace the parts if it’s a decent bet. I believe the unit is around 8 years old. since I’m here googling this issue, you might (correctly) assume I’ve lost faith in the “experts” whom I’ve asked to troubleshoot. so frustrated! your advice/insight is very welcome and totally appreciated. thanks in advance.

      • Jim Plummer says:

        Sarina s.

        Your symptoms of the compressor intermittently cutting off are pointing toward the compressor overheating. Compressors have an internal cut off to protect against overheating. Overheating can be caused by dirty coils outside, dirty coils inside, dirty filters, slow or intermittent fan motors (outside), slow or intermittent blower motors(inside), closed room vents or closed off rooms. The smell you mention would cause me to check all of the attic duct work for breaks or openings to the attic. A dirty indoor coil or clogged condensate drain may be a “smell” cause as well. If all of that looks good, you may be looking at a compressor in the process of going bad. You may improve and/or delay the inevitable by installing a hardstart device, but there is no guarantee that it would help. Probably a good time to get a professional A/C tech on site if the compressor is failing. I would start with making certain everything is clean and the airflow is good both inside and out.

        Jim

        • sarina s. says:

          dear jim, thank you so much for taking the time to reply! there’s no smell when the compressor runs, so wouldn’t that tend not to support the duct leak/clog theory? i hate the idea of needing a new compressor for an 8 yo unit, but i am pretty sure that’s where this is going. thanks again!

          • Jim Plummer says:

            Sarina s.

            “Smell” is not something that should be occurring. I always recommend fixing the obvious things first. It is amazing how often correcting the apparently unrelated and seemingly simple problems will, in the end, be the pathway to the elusive solution I was seeking. Cooler weather is just ahead your compressor may be able to carry you through to next spring before you have to replace it.

            Jim

          • sarina s. says:

            follow up question…the internal temp cut off switch you mentioned…is that usually a serviceable/replaceable part? I have an hvac company that does routine maintenance on the system 2x per year and they have never been able to duplicate the problem…they’re never here on a hot-enough day as they usually come in spring or fall. they swear up and down that the system is perfect per all their electrical and temp diff diagnostics, but I know the thing has a fault! I will try to get them out here this week as we are in a nasty heat wave and it is failing in good style during these super hot days. i haven’t bothered to call them since we have another (20 yo) unit for the rest of the house that works great. I like knowing something about what’s possibly going on so I can discuss my options intelligently. thanks again Jim.

          • Jim Plummer says:

            Sarina s.

            No the internal temp cut off switch is not replaceable. It is probably working just as it was designed to work, so replacement would not improve the operation anyway. It’s function is to shut off the compressor before it does an internal meltdown from excessive heat. You are doing the right thing to try to arrange for the technician to be there to witness the malfunction. Most techs are agreeable to working with their established customers to come quickly while the malfunction is happening.

            Jim

    • Jim Plummer says:

      Darrin,

      Yes, it can be the fan motor. When the fan motor stops running, the compressor will eventually overheat and be shut down by its internal safety. It is hard on compressors to continue to run them with no fan motor running.

      Jim

    • Darrin says:

      It ended up being the motor. It was going bad, drawing too much power (2 amps at the time it was checked where the thing is supposed to draw 1.2) and overheating and turning itself off thus not cooling the compressor so it in turn shut itself off too soon. Once the motor and accompanying capacitor was replaced the thing worked great.

  136. Will says:

    Jim,

    My Central AC unit kept running for several hours even though I turned the AC off at the thermostat. I turned the outside unit off by flipping the circuit breaker. Any ideas. Thanks!

    • Jim Plummer says:

      Will,

      If it was mine, I would be looking at the contactor located in the outdoor unit. You can take the contactor to your nearest U-FIX-IT store for free testing. Or you can use a volmeter to check it yourself. If the contactor does not open after the 24 volts is cutoff by the thermostat, then it is bad. There are other possibilities, but this is a good place to start.

      Jim

  137. James says:

    Yesterday we come home and the house was warm. I checked the outside unit and the fan was not turning but the compressor was and I don’t know for how long. Today I checked it and found the capacitor bad. I replaced the capacitor and everything come on as normal. After running all day with the thermostat set at 70 it only cooled 72 and no lower so it has ran constant all day. Could the compressor have gotten damaged from the heat not allowing it to cool properly?

    • Jim Plummer says:

      James,

      While it can shorten the life of compressors when they run without the fan motor running, it is not automatically fatal. Bad fan motors or failing fan motors can cause the capacitor to fail. I would be taking a close look at the fan motor to see if it is turning at full speed, or it it running too hot to touch.

      Jim

  138. Suze says:

    We just had a new air conditioning unit installed 4 weeks ago. Today, it stopped working. Inside, air is blowing through the vents, but the compressor fan outside is not spinning. When I turn it off, then back on, it begins to spin slowly for one second, then stops altogether. I looked, there is no obstruction blocking the fan from spinning. What could it be?

  139. Crystal Duane says:

    Our fan motor was buzzing today and no cold air was blowing out in the house. We replaced the fan motor and capacitor but the fan is still not kicking on. What else could be the problem?

    • Jim Plummer says:

      Crystal,

      I would look in the indoor unit for a wiring diagram and use it as a guide for tracing what component is stopping the power from reaching the fan motor. You can take the wiring diagram to the nearest U-FIX-IT store for free assistance in developing a trouble shooting plan.

      Jim

  140. Dan says:

    We have a central A/C. Yesterday we had people put in new flooring and left the outside doors open all day with A/C running. A/C is now not cooling but both ouside and inside units seem to be blowing. Any idea what the problem might be?

  141. CW says:

    My Ac has been tripping out in this heatwave. I have been resetting it and it will run all night but the afternoon sun has been tripping out the condenser motor and the compressor.
    What can be the solution?
    Thanks
    CW

    • Jim Plummer says:

      CW

      Fan motors tend to run hotter as they approach the end of their service life. That is probably why the heat of the day is causing the motor to cutoff this year and it did not in years past. If it was mine, I would replace the motor and capacitor.

      Jim

  142. Steven says:

    Hi,

    I know that my outside A/C fan and compressor need to be working at the same time to product the cold air. Recently, I observed that either the fan is not working or the compressor does not come on when they should. When the fan is working and the compressor is not, the fan blows out cool air (as supposed to warm air). When the compressor is on but not the fan, then the outside unit is very hot and eventually shuts off. Either way, the A/C does not cool the house down. I’ve replaced the capacitor and didn’t solve the problem. Interesting enough, this only happened to me twice, but both are under very hot outside temperatures (reaching 100 degree). Could this be a problem with the contactor? How can I visually inspect the contactor for signs of burnt out? Thanks.

    • Jim Plummer says:

      Steven,

      Contactors usually work or they do not. A visual inspection of the contacts will reveal if they are burned. The contactor controls both the fan motor and the compressor together. The contactor has no way to send power to the fan motor and compressor separately. Both the fan motor and the compressor have internal overloads that will shut them down if the internal temperature gets too hot. Fan motors tend to run hotter as they approach the end of their service life. That is probably why the heat of the day is causing the motor to cutoff this year and it did not in years past. If it was mine, I would replace the motor and capacitor.

      Jim

  143. Laura says:

    Jim,
    We went out of town for a couple of weeks and had set the thermostat to 81 degrees (we normally leave it at 80 when home). The day after, the a/c unit stopped working. I shut it off, thinking it had “frozen over” and the next morning tried to turn it back on to no avail. I checked the circuit breakers, the thermostat (fuse and batteries) and the little drain pipe outside. The drain pipe was slowly dripping, so I thought it was ok and draining fine. We called the company that installed the unit and were told they’d come out and check it for free, since it is still under warranty. When the service man arrived, he said it was a maintenance issue (maintenance is not under warranty), as the drain pipe was clogged and the pan in the attic had water in it. He reset the switch for me and I declined having him clean the drain pipe and did it myself to save the $175. Our ac was functioning just fine until yesterday evening. We suddenly noticed the temp was up to 90. We thought we’d just left the doors open too much, as the house does get rather warm when we go in and out a lot (not this warm, but it does sometimes get up to 84 if we leave doors open too long/much). I thought the air felt cool coming out of a vent last night, so we let it run overnight. Somehow, this morning it was down to 86. Still awful hot, though. This morning we had to leave for work, so I thought maybe it was frozen over again so I shut the whole unit off to let it thaw and figured we’d vaccuum the drain pipe when we got home from work. This evening, we checked the circuit breakers and thermostat as well as the drain pan and outside pipe that drips. Everything seemed fine, in fact, there was no water whatsoever in the drain pipe outside that us usually constantly dripping. The drain pan under the unit in the attic was absolutely bone dry. The a/c sounds like it is working inside, but when I checked the unit outside, the fan blade wasn’t turning at all. It looks clean as can be. Before I call out the a/c company again, I just want to be sure it isn’t something I can just fix myself. Any ideas or suggestions are very much appreciated. BTW, it is a Trane ac unit, almost 6 years old.
    Thanks,
    Laura

    • Jim Plummer says:

      Laura,

      I am concerned about your unit being “frozen over.” This is not something that should be happening. If it was my system I would start with figuring out why the “frozen over” happens. If you are closing some of the vents or some of the rooms in an effort to save money, that could be the cause. Air conditioning systems must be able to move all the air the are designed to move or they will have problems. Systems and houses must be designed from the ground up to be able to operate with parts of the system closed off.

      If the system is being operated as designed, then I would probably get a second opinion from a technician that specializes in repair rather than replacement. I suspect that the new unit is somehow mismatched to the indoor system.

      A system may not be able to keep up with a really hot day, but it should not become “frozen over” in the process.

      Jim

  144. Nghi Nguyen says:

    Dear Jim,

    I recently had to replace my run capacitor and I tested it for an hour and it was working great. I got a call from home saying that it ran great but seemed to have failed sometime in the night. I had a spare capacitor and threw that bugger in but it’s still not working and there is no buzzing coming from the unit. After disconnecting the capacitor, I for some reason, stuck it back in and I could hear the “buzz” again but it still wasn’t working. I disconnected once again and reconnected it but now there is no buzzing once again. So I’m having a hard time determining if I have a faulty capacitor or maybe that was the original cause of failure but something else got damaged as the AC was left on for hours after it had initially failed. Any thoughts? Thanks in advance.

  145. Kim Bollinger says:

    My inside unit runs fine, but once in awhile the fan outside doesn’t cut on. If I cut it off at thermostat and cut it back on a few minutes later it cuts on and works properly? What would cause this?

    • Jim Plummer says:

      Kim,

      Your fan motor is probably going bad. Older motors run hotter as they age. On a hot day they will cut out on the internal overload. Resting the motor allows the motor to cool and the internal overload resets. Probably time for a new motor.

      Jim

  146. Tonton says:

    I just bought a new capacitor 40-5 dual 370 and i replaced the new one and i did the testing before i bought the new capacitor. After i replaced the old capacitor, the inside fan is working but not cool and the compressor outside is not running. What do you think is wrong, Pls help. I can’t afford to pay to hire someone to check. Thanks!

    • Jim Plummer says:

      Tonton,

      If you replaced the capacitor with the correct one for your compressor and you have power going to the compressor and it is not running – the compressor is bad. You can try a hard start to see if you can get any additional life out of the compressor.

      Jim

  147. Chuck H says:

    Sir,

    My indoor a/c unit is running ok, and the fan outside is turning, though apparently only at approximately 50-75%, and there is air flowing from the indoor vents, but it is only room temperature, not cooling. Sounds like another bad fan? Same thing happened last year. Not ready for a yearly pattern of this. Please indicate the issue, and what might be the bigger picture problem.

    Thanks
    Chuck

    • Jim Plummer says:

      Chuck,

      You are right. The fan motor should not be failing annually. If it was my unit, I would start with verifying that the motor and fan blade are the correct one for my unit. I would make sure the fan blade is positioned correctly in the fan shroud. Finally, I would make certain the outdoor coils are clean and there are no plants or objects positioned close enough to the unit that it might obstruct the air flow through the coils.

      Fan motors will overheat and fail prematurely if they have any of the above.

      Jim

  148. Greg says:

    Hi Jim,

    My air conditioner is running fine until the hottest part of the day. Then the air stops blowing much at all and the air is not cool. Then the air blows cold for about 10-15 seconds, and then stops blowing. If I turn the unit off at my thermostat for an hour or so. The unit starts up again like nothing happened. This occurred last Sunday also. Today is Wednesday. The outside fan is running, and now the air is only slightly cool. Any ideas? PS: Did you go to the AF Academy (what years if yes)

    • Jim Plummer says:

      Greg,

      Your description of the symptoms sounds like the indoor unit is shutting down in the heat of the day. When the unit stops running, follow your 24 volt circuit from the transformer indoors until you find out what is shutting off the 24 volts. I would be looking for a condensate overflow switch.

      Jim

      • Jessica says:

        Hi so the outside compressor is working but the air hasn’t came on in our house for 5 days. It has this pipe with ice on it and it’s froze. Do you think something is blocking the air or what?

        • Jim Plummer says:

          Jessica,

          It sounds like your indoor coil is frozen over blocking the air flow. One common cause of icing on the indoor coil is air flow.

          Turn off the cooling at the thermostat and run the indoor unit on continuous fan until all of the ice melts. If it was my system, I would make sure I had clean filters and I would use a coil cleaner to to clean the inside coils and the outdoor coils. I would also make sure all of the vents in all of the rooms are open and all doors are open to any room with vents in them. Once I know the indoor coil is clean, I would make sure the air is flowing from all of the vents at normal velocity. If the velocity seems low, I would check the speed of the indoor fan motor and is the motor to hot to touch.

          Coil icing can be caused by low freon in the system. If a system is low on freon there is a leak which must be found and stopped. Otherwise the added freon will leak out again. It is usually a good time to involve an experienced service technician if you suspect a freon problem.

          Jim

  149. Maria Nguyen says:

    Hi there, for the past 3 days my breaker to the ac has been tripping every morning about the same time. The fan inside is on and blowing warm air but the fan outside is not. When I reset the breaker it comes back on. It has been really hot here about 100 and ac stays running almost all day non stop. What can it be?
    Thank you

    • Jim Plummer says:

      Maria,

      Because the tripping is not happening at the heat peak of the day, I would be looking for what other large electrical load is coming on at that time of the morning that may be causing a surge in the circuit or is there some reason the outdoor unit is cycling on and off rapidly at that time of the day?

      Jim

  150. Leticia says:

    Hi Jim,
    For the last couple of nights I noticed that the temperature in my home gets warm and I check the thermostat and see that it is rising and vents are not blowing cold air. I turn the unit off and then on again after an hour and it works again. Any suggestions or advice on what it could be? Is it dangerous to keep it running under these conditions?

    Thanks in advance for your feedback!

    • Jim Plummer says:

      Leticia,

      It is best to identify and repair the problem. The danger is minimal as long as all of the internal overloads keep shutting off the motor and compressor as they are designed to do when the internal temperatures rise. A bad fan motor that shuts itself off when it gets too hot then causes the compressor temperatures to rise until it shuts off too. The higher than normal temperatures will reduce the life of the compressor.

      Next time it quits blowing cold air, go outside and see what it running and what is not. The fan motor is usually the first to fail.

      Jim

  151. Joe Garza says:

    Thanks to your article I was able to identify a faulty capacitor. Our outside ac unit had a fan that would not start. We had it replaced Sunday night and enjoyed having ac again. However, now, two days later, the outside fan is turning off before the thermostat desired temperature is reached. Once the fan kicks back on, the house begins to cool, but it fails to reach desired temp. For example, thermostat reads 84 and is set at 74; the temp drops to about 81 then the outside fan turns off and the temp slowly climbs again, back to 84. Any idea what the issue may be? Thanks for your insightful assistance.

  152. Sal says:

    Hi Jim,
    Wrote you last week regarding my 2 tom Goodman not cooling in afternoon. Evap coil was replaced because they said it was leaking. Fixed problem for several days then back to original problem: air cold in morning and evening but blows warm in afternoon. Next they replace capacitor saying it was overheating in afternoon. Worked okay for one day. Today they installed a “Hard Start”. They said if this fails I need new compressor. What’s going on with my AC unit? Thanks in advance for your help.
    Sal

    • Jim Plummer says:

      Sal,

      I am sorry you are having a bad time with locating your problem. Hot afternoons can cause weak compressors that are starting to run hot to run even hotter and cut out on the internal overload protector. During cooler times of the day aging compressors can sometimes get by without tripping their overloads.

      This may be what is happening especially if your unit older than 7 years.

      Jim

  153. Rebecca says:

    Jim,
    Our A/C Unit stopped working yesterday. The fan is not turning, so we did the “stick” test. We got the fan to start running, but now the air coming out is not cold. Cool…just not cold. Any suggestions?

    • Jim Plummer says:

      Rebecca,

      Your fan motor is probably not running up to speed. The motor is bad when you have to start it with a stick.

      Jim

      • Greg Sheffield says:

        Jim,

        Like so many others, when the AC is on, the fan isn’t running. I can start the fan by hand (or stick) and it will then run and the house cools down. So you think it is still just a bad motor, and not the capacitor? Thank you for all your help!!!!

      • Ming Hale says:

        Hello,

        I’m not sure how and where to start a new thread with the question on this website, so hope it’s okay to “reply” to this post.

        My A/C stopped working this afternoon, the air was still blowing, not cold either, but the out door unit has stopped completely. I have noticed a small puddle of water next to the out door unite couple days ago, but today it just stopped.

        I was wondering if it could be a Freon leak since i have a older unit, and if it is a Freon leak, does the outdoor unite usual stops working all together as well?

        Thank you!

        • Jim Plummer says:

          Ming,

          Freon will not puddle since it is a gas. However, there is oil inside the refrigerant lines that can leak out when there is a break in the line. A water puddle can occur from condensation on the refrigerant line, or from a overflow condensate line being “leaked” outside to warn you that your normal condensate line is not getting the job done.

          That being said, the outdoor unit being stopped completely while the indoor unit is running is more likely power not arriving at the unit (check your breaker), the contactor or the capacitor. You can take the contactor and the capacitor to your nearest U-FIX-IT for free testing.

          Jim

  154. Dear Mr. Plummer,

    I have a Central A/C unit that is acting up. When the thermostat calls for cooling, the blowers inside runs but the unit outside does not. When I inspect the electrical on the A/C unit. I am getting 24v and 240v. The unit kicks in if I push the “plunger” on the contact relay. Any advise?

  155. william says:

    i have ductless ac. the compressor on the outside comes on runs for about a minute tne it shuts off. but the condesor fan motor stays on?

    • Jim Plummer says:

      William,

      All of the trouble shooting steps still apply. The systems are essentially the same, they just have no duct work attached to the indoor coils. Usually a bit more solid state circuitry.

      Jim

  156. Kev says:

    I moved into a new house in May. About 1.5 months back, our AC began to randomly not work. We will set it at 75, but the temperature stays at 79-80. Then, after it has run for a long time, the AC will just turn off. We had a technician come out and say there was nothing wrong with the AC, it simply needed maintenance.

    I decided to get another opinion, and had a gentleman come out who said the same thing. He performed maintenance and the AC worked well for one day. The next day it began having the same issue — not cooling the house and running until it eventually turned off. When we turn it back on, it works great. For a while.

    Any clue as to why my AC will work great and then not so great?

    • Jim Plummer says:

      Kev,

      Intermittent malfunctions are the most difficult to trouble shoot since the system must be “caught in the act” in order to have an opportunity to troubleshoot. An AC system should be able to maintain 75 degrees inside under normal circumstances. You may be able to help the process by writing down some facts whenever the system shuts down. Helpful facts might be the outdoor temperature, is the outdoor unit in direct sunlight at the time, the inside temperature at various times preceding the shutdown, is there something inside generating unusual heat, and anything else you think might be a factor.

      I takes persistence overtime to find the intermittent problem.

      Jim

  157. Courtney says:

    I just replaced my inside and outside unit 6 months ago and now it’s not cooking blowing hot air

  158. Leticia says:

    Hi Jim,
    My A/C stopped cooling last night all of a sudden. Thermostat was set to 77 and temp inside house was 80. Air was coming out of the vents but not cool. I reset the breaker and turned the unit off and on again and nothing all night unit wasn’t cooling. This morning temp in house was 83 so I turned it off and on again and all of a sudden it started cooling again. Is that normal? Should I still have someone come out to check it? Capacitor was replaced in April and still under warranty. Thank you!

  159. Sal Green says:

    Sorry this is so long, wanted to give you as much info as possible. I live in Dallas Metro area. Have Goodman 2 ton, R22 system, 8 years old. Unit sits on southside of house with no shade. Company I use is reputable and maintaining my system since new. PROBLEM: AC blows cold air morning and night, but in afternoon blows warm air. FIRST- they replaced evap coil (was previously replaced in 2011). They said it was leaking. Replacement was an ADP that uses 410 refrigerant converted to accept R-22. They said my Goodman evap coil was discontinued. Worked good for two days then reverted back to original problem. Called a/c company. They said a float was installed with the new evap coil. A/C tech thought that was problem. Had me check outside compressor & fan when unit was blowing warm air. Fan was working but unable to confirm if compressor was running. SECOND-another tech came to troubleshoot system. He replaced dual stage capacitor. It Worked one day, then reverted back to original problem. When I called a/c company today they said I might need a new outside unit. Company sending another tech to troubleshoot next week.

    WHEN BLOWING WARM AIR: the outside fan is working (unable to tell if compressor is running); both copper lines are warm; no condensation on large line; small copper line in attic at air handler evap coil is hot to touch; blower is working and it also appears water is flowing into drain line. When blowing warm air, it only lasts for 2 to 6 hours then returns to blowing cold again. This usually occurs anywhere between 12:30p and 7p. Thermostat is set for 74, temp in house will rise to 80 – 84 degrees. Thermostat is an 8 year old Honeywell programmable. Is there some way I can fix this myself? I don’t have much confidence in the company anymore and this is getting very expensive. This has been going on for over a month.

  160. Holly says:

    Hello,

    I replaced my capacitor in 2012. My ac is blowing hot air and there was freezing on my pipes. Could I just need some freon? Or could the problem be bigger. AC was also found SLIGHTLY low on R22 in 2012.

    • Jim Plummer says:

      Holly,

      Yes, it is possible that you need Freon. The only reason an AC system should need freon is a leak. Freezing of the pipes can be a sign of low freon. It can also be a sign the air flow in the inside unit is too slow which can be caused by dirty filters, dirty inside coil, bad motor, closed vents and/or closed rooms. I would take a look at those items before calling the repair tech.

      If freon is determined to be low again, an effort should be made to locate and repair the leak.

      Jim

    • Holly says:

      Why didn’t you answer my question?

  161. Brian says:

    Jim, a side question, if the compressor isn’t working much or at all and the unit ran inside/outside for 24-48 hours what does that do to the electric bill? I mean does a failed compressor still drain a lot of power? I ask because my compressor went but it took over 2 weeks to replace, I would have thought my bill would have been significantly lower due to not running any AC for those 2 weeks but the bill is almost as high as a normal month of running the AC ever was? I knew within that nearly 48 hour period there was an issue because the temperature inside the house was getting warmer, the air was no longer cool and the unit wouldn’t shut off, it ran non stop outside & inside, in fact there was a slight surge in power at one point and when I shut the unit off inside the house it took almost 10 minutes to shut down where in the past, it shut right down? If the compressor eats up most of the power and it wasn’t working how the devil did the electric bill get so high when the unit was shut down for over half the month?

    Thanks

    • Jim Plummer says:

      Brian,

      No quick answer here. Obviously, something about your failure was still allowing power to flow. A failure can leave a circuit active in a number of different ways. Always a good idea to disconnect the power from the outdoor unit when either the motor or the compressor stops running while it waits for repair.

      Jim

  162. Ray says:

    Owner of an 11 yr old Carrier 14 seer unit, today the condenser fan decided not to turn anymore. I’ve had the dual capacitor replaced about 3 yrs ago and all worked fine. I’ve found the replacement motor for the unit but I was needing to ask how do you know which dual capacitor to use. I checked the manuals and I can’t find any item upc or order number. Are all dual capacitors the same? It’s a Carrier 38EZG Model

    Thanks
    RC

    • Jim Plummer says:

      Ray,

      Look for the microfarad (mfd) rating of your duel capacitor. A dual capacitor will have two ratings. Such as 40/5 or 60/7.5. Voltage ratings are usually 370 volt or 440 volt. A 440 volt can be substituted for a 370 volt, but it is not recommended to do the reverse. Send a picture of the numbers on your old capacitor to U-FIX-IT Appliance Parts and we will be glad to tell you what it is. If the numbers on the capacitor are unreadable then look on the motor data plate for it’s mfd and on the compressor data plate for that one. You can find the compressor microfarad from the compressor model number if not mfd is listed.

      Jim

  163. Michael Boyd says:

    Two Lennox AC units outside, one for upstairs, one down. Upstairs unit is running fine. Downstairs unit is running, but no cold air is coming out of the vents inside the house. Not sure what to do. Turned off both units at the breaker panel and the furnace switch to see if a reset fixes the issue.

    Last week we had a couple of power surges in our neighborhood, but have not noticed the unit failing to cool the downstairs properly until last night. Home and units are just over two years old. Any help is appreciated.

    • Jim Plummer says:

      Michael,

      The outdoor unit should be running whenever the indoor unit is running. Verify that both the compressor and the fan motor are running outdoors whenever the indoor unit is running. Let me know what you find.

      Jim

    • Michael Boyd says:

      I should also add that the copper lines going to and from each unit outside are not frozen over. The working unit is cold and moist, the other is what I would consider room temperature. Temps have been close to 100 the last week or so, but the copper is definitely colder than that.

      • Jim Plummer says:

        Michael,

        If you have 220 volts and 24 volts arriving at you contactor on the outdoor unit and the fan motor and the compressor are not running then the contactor and capacitor need to be tested. You can take them to your nearest U-FIX-IT store for free testing.

        Jim

  164. Angela says:

    My air conditioner will blow cool air for hours and then just stop. The unit says it on cool but no air is coming out of the vents. The outside unit is not working during this time either. If I turn it off for a few hours and then turn it back on it works fine. Based on this information, do you have an idea? Thanks in advance, Angela.

    • Jim Plummer says:

      Angela,

      I would start with the indoor unit when the system is not working. Check to see if you have a safety switch on your condensate. An attic unit will have one on the drain pan and a closet unit may have a condensate pump. Your symptoms would indicate something is cutting off the 24 volt control voltage. A condensate safety switch could be your culprit. Otherwise, use a voltmeter and follow the 24 volts on the wiring diagram to identify where you are losing the 24 volts.

      Jim

  165. Adam says:

    My outside AC unit fan was not working and motor was warm/hot to touch. Turned off over night. Turned power on this morning, but no fan. Used a stick to turn and it runs. However, compressor does not sound like it is running. I believe the system has a dual capacitor. Any ideas?

    • Jim Plummer says:

      Adam,

      Take the capacitor to your nearest U-FIX-IT store for free testing. It can cause the compressor not to start. However, If th compressor runs without the fan motor running it will kick off on the internal overload. If it was mine, I would start with replacing the fan motor and capacitor. The motor is bad when you must start it with a stick.

      Jim

  166. Sam says:

    Hi,
    I turned on my AC for the first time this year. Outside the fan is running and I can hear the compressor working but I’m not getting any cold air into the house. The vents inside the house are also blowing air, but not cold air. The insulated pipe outside connected to the AC unit used to feel cold to touch when the AC was running last summer, but this is no longer the case.
    TO add to the story we recently had the AC unit disconnected and moved in order to have concrete re-poured at its base. The contractors ensured that no freon was lost when the unit was re-connected. Any suggestions on how to troubleshoot would be greatly appreciated.
    Thanks!

  167. Rudy says:

    Jim
    My AC is just blowing air at 77F in the house. When i went outside the fan on the condenser was not turning, the compressor was not turning on but it was hot (125F at the top and 135F at the bottom). I checked and I have 120v on each of the legs coming into the contactor and 30V on the coil. I have the correct voltage on the output side but still nothing turns on. What is odd is that if i give the fan a spin it will continue turning but if i put the side panel on it obviously slows down.

    The unit is a carrier so the contactor is a HN51KC024 the capacitor is 97F9895 and the motor is 5KCP39DFS773S

    Any ideas? Thank you very much in advance for any help.

    • Jim Plummer says:

      Rudy,

      If it was my unit, I would replace the fan motor and capacitor. Compressors will overheat and shutdown on the internal safety when the fan motor quits running. The compressors usually return to operating normally once the motor is replaced and moving the air properly.

      Jim

  168. Jim says:

    Jim,

    Thank you for your service and continued efforts to help diy’ers. I have a HVAC issue that I hope you can help me out with… I have two heat pumps (up/down stairs) and both outdoor units just quit running. The blowers are still blowing slightly cool air, but not nearly as cold as they should be. I checked thermostats, breakers, drip pan but all is normal. So far all looks normal….where do you recommend I go next?

    Jim2

    • Jim Plummer says:

      Jim,

      It beyond coincidental when two heat pumps quit at the same time. If they were mine I would be looking for something that is common to both systems for the malfunction. Electrical power is the first thing that comes to mind.

      Jim

  169. BONNIE says:

    My out side unit just quit the fan doesn’t move and no sound from it when I start the a/c

  170. ed kantor says:

    Jim,

    Sometimes the fan on my outside central A/C unit doesn’t come on when the thermostat calls for air. if i go outside and shake or give the unit a thump with my hand the fan comes on and the units works fine.
    Any suggestions?

    Thanks!

  171. Angela says:

    My outdoor unit made a loud bang sound and stopped running. I’ve had the capacitor replaced twice in the past month, but now it is not even running at all.

    • Jim Plummer says:

      Angela,

      Loud bangs are not a good sign for outdoor air conditioning units. Capacitors normally last for years. Going through two in a month means something is going on that is affecting the capacitor. Start with checking the circuit breakers for your outdoor unit. I am guessing you will find the breaker has cut the power to your outdoor unit. While the power is still off, use a flashlight and do a close inspection of the electrical components (follow the wires) for signs of burning. Pay close attention to the motor and compressor. If all looks good then try resetting the circuit breaker. If the circuit breaker blows again, it is time for a service call.

      Jim

  172. Matt says:

    Hello Jim,

    I had a tech come out today give my units some much needed freon and we got my downstairs unit up and running. Last season I had both of my furnace blower motors replaced and they worked wonderfully last winter. I was wandering about my upstairs unit the tech charged it with freon and replaced the relay to the outside unit whenever he was done it is now kicking out he says. He had the breaker off to the unit and whenever you flip the breaker back on both the fan and compressor kick in for a couple of seconds than both kick off. Do you have any answers on the possiblities. He said his machine said it was a high pressure problem???

    • Jim Plummer says:

      Matt,

      You did not mention repairing a leak. If the system needed freon, it should have had a leak. Your system may have too much freon. If it was me, I would find a technician with a top reputation for repair and get a second opinion.

      Jim

  173. Andy says:

    I had a reputable A/C company come out and look at my A/C unit that was making a horrible screeching sound. He immediately found a bad capacitor that was bulging at the top. He replaced and charged me $215. I know the capacitor is only a $20-$30 part but his expertise was worth the money. Then I noticed a few days later that the A/C unit screeching sound was still happening. I also noticed that the unit was on and the fan was working fine but stopped spinning while the A/C in the house was still on but the air coming out of the vents was hardly cool when the A/C fan was not spinning. The A/C tech came back out and said it was a bad fan motor so $500 later he replaced the fan motor that was much quiter when running. Thought that fixed it. But now I am noticing the same problem. A/C unit working and cooling house but A/C unit fan still turning off near end of the cycle while unit still on and making a loud screeching sound. To me it sounds like my A/C unit is bad and needs to be replaced entirely. Do you agree? Or is it possibly something else? One final note the A/C tech said my unit is 15 years old and usually that’s when units need to be replaced. Any suggestions? Thank you

    • Jim Plummer says:

      Andy,

      Yes, a 15 year old unit is a candidate for replacement. Newer units will be more efficient and new technology. Having said that, you need to determine the source of the screeching sound. If the screech is coming from the fan motor, it should be in warranty. If it is coming from the compressor, then it is probably time for a new outdoor unit. I recommend replacing the indoor coil at the same time. The quality of the installation is more important than the brand equipment. Be certain the installer is experienced and reputable.

      Jim

      • Andy says:

        Thank you so much for your reply and helpful information. To the A/C guys credit he is doing everything he can to spare me the expense of a new unit. Even going as far as contacting Carrier on what is going on with the fan since he just replaced it and the same stop start problem is occurring.

  174. B says:

    The fan did not turn on the condensing unit. I bought and installed a capacitor. The fan did not start, so I pushed the fan to start it. The fan started. the cold air line was cold, the hot air line was hot and everything seemed O.K.. A couple of hours later the fan stopped working and I assumed it was the fan motor. A A/C tech came to the house and said that the pressure was low / high (HVAC tech talk) and I needed a whole new condensing unit.

    How do you know the A/C tech diagnosis was correct? What can you do / test to see if you do need a entire condensing unit as opposed to just installing a fan motor or compressor???

    • Jim Plummer says:

      B,

      If it was me, I would replace the fan motor and the capacitor (even though you just replaced it).

      Jim

      • Alisha N says:

        My fan was not running so I also bought and replaced the run capacitor, due to a bulging capacitor. Now the fan starts immediately with the compressor, but does not cool my house below 75 degrees. The air coming from my vents is about 61 degrees. I checked my air inlet in the hallway and replaced the filter, it’s pulling air like normal. My lines outside are not frozen, i have one hot and one cold. So now where do I go with this?

        • Jim Plummer says:

          Alisha,

          The 61 degree temperature coming from the vents should be cold enough to cool the house if the system is sized properly for the house. If the unit is not large enough then it cannot keep up on the hottest days. Make certain all of your vents and doors are open. Rooms in the house that are shutoff become hot and there is no insulation in the interior walls to keep the heat from coming through to the space you are trying to cool. Make sure exterior doors and windows are sealed good. Check your duct work to make sure it is not blowing some of your cool air into the attic(or crawl space).

          Jim

      • Christina says:

        Hi Jim. 2 nights ago I noticed my split system (largest # ton capacity) of the 3 units. Degibitely by thermometer reafings blowing warmer air – so cool not cold. Outdide box fan is running. Repair tech out today said all was fine but came home and unit is running constantly and cannot cool to 81! Monday & Tuesday it was working fine and 78 in house. I want him to come back but my husband is against it. The tech did not take off the outside housing but he did do a pressure test and check freon says the husband. Any suggestions?? Thank you!!!

        • Jim Plummer says:

          Christina,

          The problem must be solved as it is happening. At the time the house is heating up check that airflow inside the house (from the vents) is normal, the outside fan is blowing strong, and the compressor is running. Usually one of those things will not be normal. Also, pay attention to the temperature outside. Every air conditioning system is designed to cool up to a certain maximum outside air temperature. If your house gets hot whenever the outside temperature is above 100 degrees, you may not have enough capacity. Patience is needed when the problem comes and goes.

          Jim

  175. Rowel Legaspi says:

    Jim,

    I have an A/C unit that the A/C stopped working. I tried resetting the breaker, and tried to turn it on and still did not work. But one thing I notice is that the fan motor is starting to warm up but is not spinning at all. I checked the motor and it’s spinning freely so I removed it from the unit and took a meter reading and reads (Black and Brown 53.8 Ohms, Brown and Purple 106.6 and Black and Purple is 52.6 Ohms) Is this an indication of a bad fan motor? Thanks for the help in advance.

  176. Gracie says:

    I have a 3 ton ac àn heat unit outside my home it was workn fine then i came home the other day it was hot in house i checked thermostat inside an there was no light no power no nutn i put batterys in it an it light up but no air comen in or out my house i went outside to look at unit the fan was running slow an nothing else works as soon as u flip breaker on to the unit fan comes on but runs slow an it set to auto inside please help its so hot here

    • Jim Plummer says:

      Gracie,

      A fan motor that is running slow is usually a bad fan motor. Take the motor and capacitor to your nearest U-FIX-IT appliance parts store for free testing.

      Jim

  177. jeff kellen says:

    where do you find the contactor? does this require taking the shroud off the compressor outside?

    • Jim Plummer says:

      Jeff,

      Follow the 220 volt power from the house into air conditioning unit. The power is normally connected directly to the contactor. You will need to remove an access panel. Make sure the power is shutoff to both the outdoor unit and the indoor unit before disconnecting the wires to the contactor.

      Jim

      • Jessica T says:

        Have a central ac unit that is 7 years old. It continually running over these past few months. Last night the unit starting making a really loud buzzing noise. The unit was hot to the touch and the fan is not turing. What should i do?

  178. Eric says:

    Mr. Jimmy, my home a/c stop cooling today, the compressor unit fan is spinning and the blower fan is blowing air to the house but the compressor is not working so their is no cool air, what could be wrong, and can I fix it?

    • Jim Plummer says:

      Eric,

      You are just about limited to testing the capacitor to see if it is bad. If the compressor sounds like it trying to start, a hard start may allow it to start and run. A compressor that has power and is not running is a bad compressor. I do not recommend a compressor change out as a do-it-yourself project. Skill, knowledge, and the correct tools are essential for compressor change outs. Be sure to check if your compressor is still under warranty which can be as long as 10 years although 5 years is more common.

      Jim

  179. Bob says:

    I just had my 1/3 HP 230 volt air conditioner fan motor replaced. The technician showed that there were 2 capacitors hooked up. a 50 MF is hooked up to the motor fan, and a 75 MF is hooked up to the compressor. The technician seemed to be somewhat surprised to see that 2 capacitors were hooked up. He tested the 75 MF and said that it is only producing 70 MF, and recommended replacing it. He said the 50 MF is ok.

    He recommended that I replace both capacitors and that a 75 MF be used with the fan motor. I don’t know much about air conditioning capacitors. So, my question is:

    Do air conditioners typically use just one capacitor for both the fan motor and compressor? If so, then that would suggest that if 2 are used then the requirements would be somewhat less and that the 50 MF capacitor might be sufficient for the motor fan. If that is true, then perhaps the requirements for the 75 MF is less as well and the fact that it is producing 70 MF is not an issue.

    What do you think? Should I replace either capacitor?

    • Jim Plummer says:

      Robert,

      I would replace the 75 mfd capacitor because it tests at 70 mfd. When air conditioners have a single capacitor, it is what we call a “dual capacitor.” That is two capacitors packaged in the same container. The function of the capacitors is the same either way, one container or two. The fan motor and compressor cannot use the same capacitor, they each have their own even when the capacitors are in the same container.

      I suspect you left out the decimal point on the 50 mfd and that it is actually a 5.0 mfd which is very common for 1/3 hp fan motor. I would have no problem with keeping the fan capacitor since it tested OK. If the fan capacitor is over 3 years old, it can make sense to replace it as a preventative measure.

      Jim

    • Bob says:

      This is additional info on my post above – the fan motor that was replaced appeared to be quite old and was probably the original motor – which was installed in 1996. The 75 MF capacitor appears to be newer, but the 50 MF looks to be quite a bit older. The compressor appears to be newer, and I’m assuming that the 75 MF capacitor was installed at the same time as the new compressor. I bought the house just over 2 years ago and the fan motor going out is the first problem I have had with the unit.

      • Jim Plummer says:

        Bob,

        Yes, a new capacitor should be installed with a new compressor and a new capacitor should be installed with a new motor as well. Look on the side of the motor to see what size capacitor is called for with that motor. There is no guarantee that the old motor and the new motor would use the same size capacitor. U-FIX-IT Appliance Parts does not warranty new motors unless the capacitor is changed at the time of installation.

        Jim

  180. Mark says:

    There is is warm air coming out of the vents inside the house but fan isn’t turning in outside unit? Any ideas? Thanks

  181. Ryan says:

    We have had our A/C units, one in the attic and one on the side of the house, for a little over a year now. We had one instance where the pan filled up and kicked off the A/C unit and we had the problem fixed. Recently we noticed that the there is cold air but it is not being blown out of the vents. I checked everything I could think of such as the drain pipes and even the outdoor fan is working but the actual “fan” that blows air into and around the interior of the house doesn’t seem to be working. Again, there does seem to be cold air just no airflow. How do I fix this?

  182. deng her says:

    hi jim. my central ac unit isnt working. when i turn it on, there is no humming from the motor and the fan doesn’t spin. i opened it up and and my capacitor still looks good. i replaced my contactor also and still nothing works. any suggestions? thanks!

    • Jim Plummer says:

      deng her

      Use a voltmeter to see if you are getting 220 volts to the contactor and 24 volts to the coil on the contactor. One of those is probably missing.

      Jim

  183. aaffan says:

    Hi
    Voltage are 200 but my a/c is working fine
    For three months but yesterday (maybe low voltage ) ac for fine but after 4to5 mints ac stops colling and throw normal air just like a fan plz help me

    Ac model gree 1.5 ton

    Many thanks

    • Jim Plummer says:

      Affan,

      You have not supplied enough information for me to identify the problem. When you air blowing inside is no longer cool, go outside and see what is happening there. Verify that both the fan motor and the compressor are running. I suspect you will find that one or the other is not running. Let me know what you find and I can give better advice.

      Jim

  184. Chris says:

    There’s more helpful information in this thread than the entire rest of the Internet, thank you Jim for sharing your expertise!
    Problem: Air conditioning ceases cooling the house until I turn off the outdoor unit breaker for about 10 minutes then turn it back on. Seems like something gets reset so that it cools again–for about a day before having to repeat the process.
    Also, the compressor seems to be running all the time or almost all the time, no matter whether the outdoor fan and indoor fan are running or not, even if the thermostat is switched from ‘cool’ to ‘off’. Nothing seems to stop the compressor but turning off the breaker.
    The following is pretty long-winded, sorry: I turned the thermostat to ‘off’, the indoor fan and outdoor fan were both off and yet the compressor was running. The exposed copper pipe coming out of the indoor unit was hot to the touch and it sounded like something was quietly running in the indoor unit. Then I turned off the breaker for the ODU and the compressor stopped, the noise in the IDU stopped and the copper pipe cooled off. Heard some gurgling and hissing in IDU (evaporation of refrigerant, right?). After about 10 minutes, I flipped the ODU breaker back on. The compressor kicked on immediately and the copper tube got hot again. I went upstairs to the thermostat and switched it from ‘off’ to ‘cool’ and there was a relay click from the thermostat, but system light didn’t come on because the room temp was cooler than the setting. Back downstairs at the indoor unit, the copper tube was quite cold–it apparently went hot to cold by turning the thermostat from off to cool. But then over a couple minutes the tube warmed back up and got hot to the touch again, all while the compressor has been continuously running. Back at the thermostat, I turned down the setting until the system light came on and the outdoor fan started (up until now, neither fan was running). It ran for about 10 seconds at full blast and then slowed down very slightly. Went downstairs and the copper pipe slowly cooled and got cold. Then the indoor fan kicked on and cold air was blowing from the vents. When the room got down to the set temperature, the system light went off, the outdoor fan went off, and after about a minute the indoor fan went off. Yet the compressor was still running! And the copper pipe went from cold to hot again.
    In other words, when it’s not cooling the house the compressor is still running while both fans are off and it is making the copper tube hot.
    It cools the house for a day or so before system no longer makes cold air. At which time I cycle the ODU breaker again to bring it back to life for a day or so.
    Any idea why it stops making cold air? Why cycling the breaker fixes the trouble? Why the compressor runs when both fans are off? Obviously this is going to make my electric bill sky high if the compressor never turns off, not to mention wear it out? Shall we call a tech?

    • Jim Plummer says:

      Chris,

      The compressor is probably cycling off on the internal overload. because the fan motor is not running. Turning power off to the compressor allows the compressor to cool and resets the internal overload.

      The key to solving your problem lies in determining why the compressor is running when the outdoor and indoor fan motors cycle off. Normally the compressor receives it’s power from the same contactor that powers the fan motor. It appears the contactor is working since the fan motor shuts off. While the fan motor is cycled off and the compressor is running, use a voltmeter to determine where the power is coming from that is running the compressor. Consult the wiring diagram for the outdoor unit to help identify possible circuits that could supply the power. Once you identify where the power for the compressor is coming from, the solution will probably be self evident.

      Jim

  185. Ilse says:

    We have had our coil replaced and recently, a new condensor installed w/ drier and indoor txv for a the coil. We are out over 2000.00 and the temperature in our house will not go below 77. What could the issue be?

    • Jim Plummer says:

      Ilse,

      If it was mine, I would be looking at the recent installation. Time to call an expert air conditioning technician and make certain the installation was done correctly. A bad installation can shorten the life of your new condenser. The installation is more critical than the manufacturer in determining your long term satisfaction.

      Jim

  186. Noony says:

    I recently made a service call to get my AC looked at cause the fan wasn’t spinning. Repair man looked at everything and told me my fan motor was causing the issue and it needed to be replaced, along with the fan blade.

    I got that replaced today and I’m still experiencing the same problem. The fan started spinning when I first powered it on and got cold air in the house, but I had to leave to go out of town.

    When I came back the air happen to be on at the time because we have it set to AUTO, but the air was no longer cold. Checked outside and sure enough the fan wasn’t spinning again. Switched the breaker to turn off the A/C/Furnace and switched it back on, could not get the fan to spin whatsoever and tried different settings, AUTO or CONTINUOUS to no avail. Decided to leave it alone for about 30mins to an hour and tried turning it on again. The fan started to spin and inside the house had cold air through the vents, but not even 10 minutes after, started getting just normal air coming through. The fan once again stopped spinning.

    I’m suspecting a bad capacitor, but could it be something else?

    • Jim Plummer says:

      Noony,

      It could be a bad capacitor, but that should have been replaced when the motor was replaced. Your symptoms could also be caused by a mismatched motor, a mismatched fan blade, the motor turning the wrong direction and last but not least, the replacement motor could be bad.

      I hope that helps.

      Jim

  187. Alejandro Maciel says:

    I had this problem going on for way too long, my fan was not kicking in, had a “tech” come and look at it and he replaced the fan motor and the Fan worked but it still did not blow cold air. Had the local Edison Company come and put in a new Thermostat Unit for free and the A/C unit still did not turn on, i checked the breaker and it has never tripped. I replaced the filter and still nothing. You can hear air being sucked in through the filter, and you can feel the air (not cold) through the vents of the house. I noticed that when i turn it on, There is a humming/buzzing noise coming from the unit and sounds as if its trying to kick the compressor over. The Fan works like a charm and spins without a hassle, but i don’t know why my a/c unit won’t cool?

    Could you please please help me and try to guide me in the right direction.

    • Jim Plummer says:

      Alejandro,

      Your symptoms are pointing toward the compressor failing to start and run. A compressor not running can be a bad capacitor. Shut off the power to the outdoor unit and the indoor unit. Discharge the capacitor by shorting between the terminals of the capacitor with an old screwdriver after the power is shut off before touching any bare terminals. Remove the motor and capacitor and take them to your nearest U-FIX-IT store for free testing.

      If the capacitor tests good, you can try installing a hard start which sometimes helps old compressors start up and run. The hard start at best can buy you a little more time before your compressor will have to be replaced. I do not recommend compressor replacement as a do-it-yourself job.

      Jim

  188. Kyle says:

    Jim, recently we’ve had very nice weather so we’ve had the units turned off. I have to units outside. It heated up the other day so we turned the two units back on and everything is working. everything powers on the and the fans do spin at their normal rate. However, my unit that controls the downstairs AC is blowing, but not blowing cool air. I’ve replaced the filter, checked to make sure everything was working as it should. I have an old unit and last year had the same problem. A tech came out and told me all it was, was that inside the unit in my basement there is a plastic piece that pulls water through one hose and then out the other. The problem ended up be that the plastic piece got clogged. Cleaned that out again last night and it’s still not blowing cool air.

    • Jim Plummer says:

      Kyle,

      You seem to be describing a condensate pump with a hose that was clogged and therefore unable to pump water. When the condensate reservoir is full a float switch will cut off power to the air conditioning unit to prevent water overflowing the condensate reservoir. However, your outside fan motors are spinning at normal rate. That makes it unlikely that the condensate safety switch is the cause of your “failure to cool”(the float switch would cut power to the fan and the compressor both). Check to see if your compressor is running. If the compressor is not running, check the capacitor. Shut off the power to the outdoor unit and the indoor unit. Discharge the capacitor by shorting between the terminals of the capacitor with an old screwdriver after the power is shut off before touching any bare terminals. Remove the motor and capacitor and take them to your nearest U-FIX-IT store for free testing.

      Jim

  189. Dallas Elliott says:

    Hi! We thought something was wrong with our unit because it wouldn’t keep the house cool well turns out our windows were cracked at the top! This was last week . Closed and locked all of the windows and has been working fantastic maintaining the correct temperature. I get home today and its burning up! The ac was on but the vents were not blowing cold air just barely cool air. Checked the unit outside and the fan at the top is spinning but I don’t think I hear the actual unit running! Help!

    • Jim Plummer says:

      Dallas,

      A compressor not running can be a bad capacitor. Shut off the power to the outdoor unit and the indoor unit. Discharge the capacitor by shorting between the terminals of the capacitor with an old screwdriver after the power is shut off before touching any bare terminals. Remove the motor and capacitor and take them to your nearest U-FIX-IT store for free testing.

      If the capacitor tests good, you can try installing a hard start which sometimes helps old compressors start up and run. The hard start at best can buy you a little more time before your compressor will have to be replaced. I do not recommend compressor replacement as a do-it-yourself job.

      Jim

  190. Kiera says:

    We have an all-in-one unit outside, similar to that in mobile homes. When the fan is turned to on at the thermostat, air is pushed through the vents. When we turn it to cool, the fan continues to run, but it does not get cold. When I look at the unit, the large fan I can see is not turning and occasionally we hear a buzzing sound. We had a service tech out recently and he changed three capacitors and cleaned the coil. Once it was running at full capacity, it blew the breaker. We replaced the breaker (yes, the breaker and not just a fuse) and now we’re having this issue. We are planning to replace the unit entirely, but until I can get someone out to do this, it’s there anything I can do to get ac back?

    • Jim Plummer says:

      Kiera,

      From your description it sounds like the “large fan” motor may be bad. Shut off all power to the outdoor unit. Discharge the capacitor by shorting between the terminals of the capacitor with an old screwdriver after the power is shut off before touching any bare terminals. Remove the motor and the capacitor it connects to and take them to your nearest U-FIX-IT store for free testing.

      Jim

  191. colby says:

    My inside blower is working but the outside unit is not and no air coming out the vents. What do i do

    • Jim Plummer says:

      Colby,

      Start by verifying that you have 220 volts arriving at the outdoor unit. If you have 220 volts to the outdoor unit and it is not running, the most common problems are the contactor or the capacitor. Shut off the power to the outdoor unit and the indoor unit. Discharge the capacitor by shorting between the terminals of the capacitor with an old screwdriver after the power is shut off before touching any bare terminals. Remove the contactor and capacitor and take them to your nearest U-FIX-IT store for free testing.

      Jim

  192. Mirelle says:

    Hi- my outside unit stopped running. Inside furnace and thermostat looks fine. We just had a company come out, he changed the blown fuse and compressor but still the outside unit would not turn on. He suggested I replace the entire system. Should I get a second opinion?
    My only concern is that he didn’t even check inside unit at all. I know nothing about this but I don’t wanna replace the entire thing if not absolutely nessesary .

    Thanks

    • Jim Plummer says:

      Mirelle,

      Yes, a second opinion is a good idea. Talk to your friends for a recommendation of someone who has made a repair on their air conditioning unit as opposed to a replacement. Unfortunately, there are those who sell the replacement rather than make the repair. This time of year we all want to be cool as soon as possible which makes us easy targets.

      Most technicians will not make a diagnosis without looking at the inside unit also.

      Your guy may be just fine, but a second opinion cannot hurt anything. Good luck.

      Jim

  193. sarah says:

    My AC unit blows cold air and works really great when it runs. However after the unit runs for a little while it stops. i hear a noise in the unit but the fan on the unit isn’t running. If I turn the unit off for about 5 minutes and back all works great again for a little while. So far the thermostat has been replaced, capacitor, some wire to the thermostat and some contactors have been replaced but I’m still having this issue. Please help I have no idea what is going on and have someone out here 4 times

    • Jim Plummer says:

      Sarah,

      Your motor is probably bad. Motors have an internal overload protector that turns the motor off when it gets too hot. Old motors run progressively hotter as they age. The motor will run on cooler days and nights, but will cut out on the hot days. It will eventually start to run slow and/or stop totally. A new motor and capacitor (always replace the capacitor when you replace the motor) is probably the solution you need.

      Jim

  194. Arslan Aslam says:

    hi my indoor system is working but tge current is not passing into outdoor unit and compreser is also quite running but not cooling

    • Jim Plummer says:

      Arslan,

      If you have 220 volts to the outdoor unit and it is not running, the most common problems are the contactor or the capacitor. Shut off the power to the outdoor unit and the indoor unit. Discharge the capacitor by shorting between the terminals of the capacitor with an old screwdriver after the power is shut off before touching any bare terminals. Remove the contactor and capacitor and take them to your nearest U-FIX-IT store for free testing.

      Jim

  195. David says:

    Hi Jim,
    My Goodman AC unit sounded bad yesterday. After looking at it, the fan motor was not working and it was very hot. The compressor was working fine. What do you think should be my next step, replacing the motor?
    Thank You.

    • Jim Plummer says:

      David,

      Yes, I would replace the motor and capacitor if it was mine. Your motor is probably bad. Motors have an internal overload protector that turns the motor off when it gets too hot. Old motors run progressively hotter as they age. The motor will run on cooler days and nights, but will cut out on the hot days. It will eventually start to run slow and/or stop totally.

      Jim

  196. Julie says:

    Earlier we noticed that although the air is blowing inside, it was getting quite warm. We then realize that the breaker had skipped and once we switched it, it again got cool. Later we did realize yet again that it was warm and realized that the upstairs unit outside was not running. Air is blowing both up and down stairs but it is warmer upstairs.

    • Jim Plummer says:

      Julie,

      If your unit is blowing the circuit breaker repeatedly on the outdoor unit, you need to locate what is causing it. Your description leaves a number of possibilities.

      After resetting the circuit breaker check to make certain the fan motor is turning and blowing air vigorously. If not, then it will be the cause of the compressor overheat and subsequent circuit breaker pop. If the air is blowing vigorously then proceed to the next step.

      Checking the filter(s) is clean on the indoor unit. Make certain all of the vents are open in every room and you have good air flow out of the vents. Restricted airflow can cause the indoor coil to ice up which will cause the compressor (in the outdoor unit) to overheat.

      Check the outdoor coil for obstructions or dirt clogging the spaces between the fins and clean as needed.

      If all of the above is good, then call your nearest U-FIX-IT store for more personalized help.

      Jim

  197. Robert says:

    Outside unit humming loudly ,fan not turning.watched goggle and followed suggestion to replace capacitor. Worked great (for 30 min.) then fan stopped running. Let cool over night and turned it back on worked for 20 mins.. Any suggestions please!!!!!!

    • Jim Plummer says:

      Robert,

      Bad news, your motor is probably bad. Motors have an internal overload protector that turns the motor off when it gets too hot. Old motors run progressively hotter as they age. The motor will run on cooler days and nights, but will cut out on the hot days. It will eventually start to run slow and/or stop totally.

      Jim

      • Erin says:

        Hi Jim

        When we turn our air conditioner at thermostat air came through the vents inside but the air was not cold. We went out Side to find our air conditioner was making a humming noise and the fan was not turning there were no other noises Coming From The unit, which is 8 years old.
        We took a stick and manually turned the fan and it slowly started to fire up. Then we waited for the house to cool down. After about 45 min the house was no cooler and the air coming through the vent wasn’t cold. So we just shut the air conditioner off. We looked at the capacitor and it appears to be a little bulged at the top, resembling a can of pop that has been dropped. Could it be the capacitor or the motor? What is the going price to fix either of those.

        Thank you for your information
        Erin

        • Jim Plummer says:

          Erin,

          A bulging capacitor is usually a bad capacitor. Your motor symptom usually indicates a bad motor as well. Shut off the power to the outdoor unit and the indoor unit. Discharge the capacitor by shorting between the terminals of the capacitor with an old screwdriver after the power is shut off before touching any bare terminals. Remove the motor and capacitor and take them to your nearest U-FIX-IT store for free testing. Capacitors cost $15 to $50 depending on size. The common motors usually run from $155 to $189 unless you have an odd ball motor. Bring the model and serial number off your outside unit just in case we need it. 95% of the time U-FIX-IT has the motor you need in stock.

          Jim

  198. Dave says:

    My unit decided to stop cooling last night. The compressor will come on but not the fan. The fan did start with a pencil and ran at full speed ( I assume) for a half-hour or so and cooled fine while it did. I turned it off when I noticed it was not blowing cool air anymore.

    This morning I started it up in the same manner. Like before, it ran about 15 to 20 minutes and the cool air stopped. Checked outside and the fan was stopped but the compressor was still running. Shut it off before the compressor overheated. Last night the motor surface was too hot to leave my hand on for long.

    Sound like a bad motor to you?

    • Jim Plummer says:

      Dave,

      Yes it sounds like a bad motor to me. Motors have an internal overload protector that turns the motor off when it gets too hot. Old motors run progressively hotter as they age. The motor will run on cooler days and nights, but will cut out on the hot days. It will eventually start to run slow and/or stop totally. It sounds like yours is at the end of its life.

      Jim

  199. Tony says:

    Hi Jim,

    The compressor fan inside my outside unit sometimes stop turning and my compressor keeps humming (I think it still running). If I turn the AC off for 5 or 6 hours then restart it again the fan runs and the unit inside the house blows cool air.

    Few days back this method stopped working. So then I sprayed the side of it with water for few minutes. Then I waited for 1/2 hr for AC to dry and turned it on again and it worked. I did this twice and it worked so far.

    I’m trying to find out if the capacitor, contactor or the fan motor is bad? Thanks!!

    • Jim Plummer says:

      Tony,

      It can be either or both. You can take your motor and capacitor to the nearest U-FIX-IT for free testing. If the capacitor tests good, then you know it is the motor. A capacitor can be tested with a multi-meter that has capacitor testing function. Or, you can replace the capacitor first and see if that fixes it, since it is significantly cheaper than the motor. It does, however sound like your motor is bad.

      Jim

  200. Mary Stokes says:

    My air conditioner will not even turn on inside. I turned the fan switch on that was inside the wall part where the filter is found and the fan is working but I can not turn it on from the switch on the wall. Any ideas?

    • Jim Plummer says:

      Mary,

      Your air conditioning system is controlled by a 24 volt circuit that runs through your wall thermostat. A voltmeter is required for locating the problem rather than changing parts until the part you change fixes the problem. Look for a wiring diagram on the back of one of the panels of the furnace. It is your roadmap for tracing the circuit. I recommend starting at the furnace and measure for 24 volts at the transformer. If you do not have 24 volts, disconnect the power to the furnace, remove the transformer and take it to your nearest U-FIX-IT for free testing. For additional assistance, call the U-FIX-IT appliance parts store nearest you for help with the troubleshooting process.

      Jim

  201. Karen Schiff says:

    My upstairs AC unit is not cooling. When I went outside both units were working and blowing warm air out of the top of each unit. The downstairs unit is cooling perfectly. The upstairs unit is not. We cleaned the coils but to no avail. Today I went outside and the large unit for the downstairs was running and blowing warm air out of the top of the unit. The upstairs unit was running but today the air coming from the top of the unit is cool. Do you have any ideas on what’s happening and should I turn my upstairs unit off.

    • Jim Plummer says:

      Karen,

      Cool air coming from the outdoor unit is a sign the freon is not moving through the system the way it should. 1st step is to determine if the compressor is running by listening for the distinctive hum of the compressor.

      If the compressor is running, it is time to call an experienced air conditioning tech to determine the best course of action. Test instruments and skill will be required to locate an repair the problem.

      If the compressor is not running, disconnect the power from the outdoor unit and remove the capacitor. Be sure to discharge the capacitor by shorting between the terminals with an old screwdriver after the power is shut off before touching any of the bare terminals. Take the capacitor to your nearest U-FIX-IT store for free testing. If testing is not an option, you can replace the capacitor to see if the compressor will start. Installing a hard start kit is another option to try to get a little additional life out of a compressor. If you changing the capacitor and installing a hard start fails to start the compressor, then the compressor is probably bad. It is best to consult an experienced air conditioning technician at this point.

  202. Amy says:

    Every other weekend i am calling a service tech over. Last summer got a brand new unit installed. My a/c has always been set at 73 . But either the outside unit is not turning or the outside and inside is freezing. Summer’s in florida are hot as heck. I just dont know what to do. This unit is brand new. Please help

    • Jim Plummer says:

      Amy,

      Your symptoms are not sufficient for me to give you any usable direction. Call the U-FIX-IT appliance parts store nearest you for help in determining whats wrong. A brand new unit should not be giving you trouble. If the company who installed the unit is not having success putting it in good working order, you may want to consider getting a second opinion by calling another company and paying the service call for them to diagnose the problem. The “freezing” part of your trouble makes me wonder if the system is charged correctly (with freon). The best service companies do not “guess” as to what is wrong. They have the right equipment and the expertise to identify the problem before they start changing out parts.

      Jim

  203. Adam says:

    I just had a contractor replace the fan motor in our Lennox outdoor unit, after it stopped cooling over the weekend. Late this afternoon, after adjusting the thermostat somethe unit stopped cooling again. After checking the outdoor unit, I noticed the fan wasn’t turning very fast, and it sounded like it was strugling (buzzing), and the top of the fan motor was hot to the touch.

    I tried turning off the the inside thermostats, and power to the unit to let it cool, and start again, but it was still the same. Any thoughts?

    • Jim Plummer says:

      Adam,

      Call the contractor who replaced the motor and let them know what is happening. A new motor should not be struggling as you describe and most contractors will want the opportunity to make it right. New motors come with warranties, because they occasionally fail prematurely.

  204. Sandra pope says:

    hello, my central heating and air unit isn’t working properly. I’ve noticed for about three days with temperature set on 70/73 the thermostat reads higher. Today I came home to 88 degrees with temperature set for 70!!!! The weather is like 95+ outside. So when checking my unit outside I have NO sound and fan isn’t moving at all! I was told my compositor was bad. Do I need to replace the entire system. Manufacture date is 2005. It’s a 3 ton Trane system. Please help before I spend money not needed… I am a single female. Thanks

    • Jim Plummer says:

      Sandra,

      Verify that you have electrical power going to the outdoor unit. If the power is good and the unit is not running then disconnect the power to the outdoor unit and also to the indoor unit. Remove the contactor and the capacitor and take them to your nearest U-FIX-IT Appliance store for free testing. Be sure to discharge the capacitor after disconnecting the power to the unit by shorting between the terminals with an old screwdriver before touching the bare terminals. Check our air conditioning parts page if you are unsure what the contactor and capacitor look like. Call your nearest U-FIX-IT store if you still have questions.

  205. Jay says:

    So I had the air condintioning on cool for the day and suddenly it starts making a loud and constant rattling noise. It does not seem to stop. I tried spraying some water into the fan area to see if i can clean out debris and start it again, but to no avail. Any idea what could be making this load rattling noise? Worried to have the AC on while so loud. We only changed the capacitor maybe 8 months ago. Could it mean I need to change it again so soon?

    • Jim Plummer says:

      Jay,

      First step is to identify the source of the noise. Cut the power to the outdoor unit and disconnect one of the motor leads. Turn the power back on. If the noise has stopped, your motor will be the problem. Remove the motor and take it to your nearest U-FIX-IT store for free testing to verify it is bad. If you still have the noise, then the problem will be the compressor. Call your nearest U-FIX-IT store for your next step.

      Jim

  206. Rahman says:

    My outdoor unit does not working. I checked A/C circuit breaker and turned on and off. Thermostat cooling setting put below 24 degree and put on Auto setting. Still outdoor unit not working.. I have LENOX model. Please advise..

    • Jim Plummer says:

      Rahman,

      Turn off the power to both the indoor unit and the outdoor unit. Remove the transformer and the capacitor and take them to your nearest U-FIX-IT store for free testing. Be sure to discharge the capacitor after the power is turned off by shorting between the terminals with an old screwdriver before touching any bare terminals. Failure of either the transformer or the capacitor can can cause the outside unit not to run.

      Jim

  207. Robyn says:

    We had the power off in our house for 9 days. We got home today and can’t I can’t get the air on. The inside fan is working but the outside unit isn’t working. The unit was working before we left. Any suggestions? I have turned the breaker off and the thermostat and waited a minute each time before turning it back on. Any help would be appreciated.

    • Jim Plummer says:

      Robyn,

      Disconnect the power to your outside unit and the inside unit both. Remove the contactor and the capacitor and take them to your nearest U-FIX-IT store for free testing. Check our air conditioning parts page for a picture of a contactor and capacitor if you are unsure what they look like. Discharge the capacitor by shorting between the terminals before touching bare terminals. If you have a multi-meter call your nearest U-FIX-IT store for help in how to test these items without removing them.

      Jim

  208. Kwan says:

    Leno outside unit not working. Pressing contactor button turns unit on. But goes off if button not pressed. Do I have a bad contactor?

  209. Jeffrey says:

    My outside unit stopped running last night. turned it off for the night. This morning trying to diagnose the problem.

    When I start the AC unit the fan hums but wont turn, gets hot. If I push start the blades it will run (slower than it should) for a minute or two, but stops all together after that and no sound. If I restart the system it will repeat this process. If I replaced the capacitor would it likely fix this issue…or is it just a bad fan motor, or both?

    • Jim Plummer says:

      Jeffrey,

      It could be a bad capacitor, but you have the classic symptoms of a bad motor. Take your motor and capacitor to your nearest U-FIX-IT Appliance Parts store for free testing.

      Jim

  210. Ron says:

    Hi Jim,

    Every year when I turn on the AC unit for the first time (today), the outside unit kicks in, but shortly thereafter, the outside unit goes silent, don’t hear any noise/fan spinning. The thermostat is set at 70 with outside air in the upper to mid 80s today. Air is blowing inside from the vents, but thermostat shows 82 despite set at 70. After 5 hrs, house not cooling based on settings.
    Every year I call a repair guy and he comes out and gets the outside unit running. What is occurring every yr that I need to call for service to get the outside unit running?
    Thanks in advance for your thoughts on this.

    • Jim Plummer says:

      Ron,

      The initial startup after sitting idle for an extended time is the most likely time for weak components to fail. Quality service techs are usually happy to explain what failed and show you the failed components. I recommend asking questions about repairs until you understand what was wrong and what was done to repair the problem. Knowledge and communication is essential to building trust with your service tech.

      Jim

  211. Marissa Smithson says:

    Came home to ants in the contactor and A/C not working. First time, a/c service tech just blew the ants out of contactor. A week later, a/c not working again. Service Tech replaced contactor. Next day, unit not working again – Service Tech replaced capicitor. Not 24 hours later, unit is not running again. Ideas?

    • Jim Plummer says:

      Marissa,

      If neither the compressor or the fan motor is running then use a multi-meter to check for 220 volts and 24 volts arriving at the contactor. If your voltages are good then disconnect the power to the outdoor and the indoor unit. Remove the contactor and the capacitor and take them to your nearest U-FIX-IT store for free testing.

      If just your fan motor is not running, then disconnect the power to the outdoor unit and remove the capacitor and the motor and take them to your nearest U-FIX-IT store for free testing.

      Jim

  212. David says:

    Hello, I have dual ac units. Both fans are not working, which I find extremely odd (and no noice at all coming from outside AC units). AC pumps warm air. Please help!

    • Jim Plummer says:

      David,

      I agree with you. It is odd when two units have identical malfunctions. Use a multi-meter to check for 220 volts and 24 volts at the contactor on each unit. I suspect you may be missing one or the other.

      Jim

  213. ethel stafford says:

    When I turn my ac on it trips breaker fan blows on inside not cooling fan be turning outside

    • Jim Plummer says:

      Ethel,

      Disconnect the power to the outside unit. Remove the contactor, the capacitor, and the fan motor and take them to your nearest U-FIX-IT store for free testing. Take a picture of the wire connections prior to disconnecting your wires. One of these items is most likely causing your fan not to turn and blow the breaker. Call your nearest U-FIX-IT store if you have questions about how to proceed.

      Jim

  214. Juana says:

    The power went out in our house due to a faulty cord. I reset the breaker and the power came back on except now the air conditioner does not work. It blows out air but only hot air.

    Also I went outside to check and the fun is not running. I don’t hear the unit working but I heard it when it “turned”in. I also reset the ac’s breaker but nothing.

    • Jim Plummer says:

      Juana,

      Disconnect the power to the outside unit. Remove the contactor, the capacitor, and the fan motor and take them to your nearest U-FIX-IT store for free testing. Take a picture of the wire connections prior to disconnecting your wires. One of these items is most likely causing your fan not to turn and blow the breaker. Call your nearest U-FIX-IT store if you have questions about how to proceed.

      Jim

  215. Jay says:

    Hi Jim,

    I was reading you post about the AC not blowing cool air. I have the same issue. It just blows air, but it is not cool. When I check the fan outside, it is not spinning. But i hear a small buzz coming from it. So I tried to spin it with a stick, still it would not run. I looked at the condenser and it did not look bad to me. What else do I have check? Please advice and thanks for your help!

    • Jim Plummer says:

      Jay,

      The most common items to fail on an outdoor air conditioning unit are the contactor, the capacitor and the motor. To identify which one is the problem turn off the power to both the outdoor unit and the indoor unit of your a/c system. You can remove those items and take them to your nearest U-FIX-IT store for free testing. If you have a multi-meter you can check for 220 volts going into the contactor and coming out of the contactor. If you read 24 volts on the coil of the contactor and you do not have 220 volts leaving the contactor, it is a bad contactor. If the top (under the terminals) of the capacitor is swollen or rounded, the capacitor is most likely bad. Be sure to discharge the capacitor before touching the connections. The capacitor can be checked with an ohm meter (mult-meter). Call the nearest U-FIX-IT store for an explanation.

      Jim

  216. Jay says:

    Jim I have had several experiences with air conditioners in the last ten years and my neighbor brought something to my attention yesterday that I am still trying to figure out. They had tbeir service company come by to do an annual cleaning and wound up replacing a start capacitor for the fan inside as well as a 1 1/2 pole contactor. The unit was working properly before the annual cleaning service. It is working just as well now but I have replaced several capacitors and contactors for various units and machines that we own but I haven’t ever heard of someone doing it as preventative maintenance. I may be out of line or just ignorant but a capacitor either works or does not correct? I have been popped by one but never been able or willing to open one to see if it is wearing unusually or looks like it is burning up or bubbling out. It is either bad or not bad. It is a trane 3 1/2 ton heat pump. Standard issue probably 4 thousand of them within ten miles of where I am sitting and I don’t think I have ever heard someone say “man if you had just changed out that capacitor 2 months ago it would still be pumping” Help me out before I call these guys and let them have it. Yes they charged them 76.00 for a media filter and 300.00 for the contactor and capacitor. Wow….thats why we DIY

    • Jim Plummer says:

      Jay,

      Everything on God’s green earth has an average life span including air conditioning parts. The engineers design a life span into the air conditioning components they design to avoid making things prohibitively expensive. While the “do-it-yourselfer” and the technician appear to be accomplishing the same job, there are actually two different mindsets at work. From the DIY point of view we generally want to squeeze all of the life out of things we can and because of that we run things until they fail.

      From the air conditioner technician’s point of view (that is performing annual servicing and cleaning) the objective is preventative maintenance. It makes sense that a technician will have records that show the “average time to failure” for the high use components in his area. It also makes sense that it will be cheaper for the customer to replace these on a scheduled maintenance visit rather than on a service call when it fails. There is also the nuisance factor of having to wait until the technician arrives. Finally, there is the problem that arises when a component fails within a few weeks of a technicians visit for annual cleaning. It looks as though the technician missed something or worse.

      Providing service at the home involves expenses that are not readily apparent. I do know it is difficult to pay too much for excellent service. Having said that, there is money to be saved if you accomplish your air conditioning repairs and preventative maintenance yourself.

      Thank you for your observations and for being a DIY advocate.

      Jim

  217. PeeKayM says:

    Hi Jim,
    I have split HVAC system in our home,last weekend found that cold air is not coming but indoor fan was running. I put the fan manually off (switch where the indoor unit is located). If I put the switch on the fan continue to run irrespective of the thermostat setup. In sitch-on condition, fan Auto or ON, it always runs. If I set the AC in thermostats, cold air is not coming. Checked the outside unit, neither fan is running nor any sound is coming from the compressor. Could you please suggest me where the problem might be ?
    Thank you.
    PeeKay

    • Jim Plummer says:

      Peekay,

      Turn off the power to the outdoor unit and to the indoor unit. Remove the contactor and the capacitor and take them to your nearest U-FIX-IT store for free testing. Call the nearest U-FIX-IT store if you have questions on how to proceed.

      Jim

      • PeeKay says:

        Hi Jim,
        Thank you very much for your response. I changed the contactor but it still does not work. The Outdoor fan and compressor is not getting started. It has dual capacitor and one start capacitor, should I take both the capacitor or just the dual one ?

        Thank you,
        PeeKay

  218. Dan says:

    My outside AC unit will turn on but it will then quickly turn off without blowing any cool air into the house. Any suggestions?

    • Jim Plummer says:

      Dan,

      I need more information to be of any help. Please verify if the is a split system with a separate indoor unit and outdoor unit? Is this a package unit with the furnace and a/c combined in the outdoor unit? Is it a window unit a/c? Is the compressor still running while the air blowing inside the house starts up and then stops?

      Jim

  219. David Lobosco says:

    My air conditioner broke on the weekend. It is running inside, blowing air out vents. The fan on the outside unit is not running. When I get close to hit I can here a buzz but it is not tripping on. I was just curious if anyone knew if this was a sign of a big problem or just something minor.

    • Jim Plummer says:

      David,

      Your symptoms are not enough to be definitive. If he buzz is being caused by the motor and the compressor is running, it can be a bad motor or a bad capacitor. Take the motor and the capacitor to the nearest U-FIX-IT store for free testing. If the buzz is caused by the contactor and both the motor and the compressor are not running, the contactor may be bad. Take the contactor to your nearest U-FIX-IT store for free testing. Make certain you disconnect all power from the outdoor unit and the indoor unit before removing any of the components. Discharge the capacitor prior to touching any electrical connections.

      Jim

      • David Lobosco says:

        Hi Jim,

        Thanks so much. When I turn the air on and move the fan with a stick, it starts up and runs cool. When the air goes off, then the fans stops and I have to start it again. Our home is under warranty so someone is coming today. I just hope it won’t take forever to fix. Since it runs once I start the blades, I am thinking the motor is okay.

        • Jim Plummer says:

          David,

          I am sorry to be the bearer of bad news, but your fan motor is probably bad. Those are classic symptoms of a bad motor. You can take the motor and the capacitor to your nearest U-FIX-IT store for free testing.

          Jim

  220. Smurphy says:

    My air conditioner and air blower suddenly stopped working at the same time. No fuses were tripped. Is it unusual for both units to stop working at the same time, or is that how it usually happens? They are about 10 years old.

    • Jim Plummer says:

      Smurphy,

      The low voltage (24 volt) system is common to both the outdoor air conditioner unit and the indoor air blower. The source of the 24 volts is the transformer which is usually located on the indoor blower unit. A bad transformer is likely for your symptom. Use a multi-meter to measure the voltage going into the transformer (110 volts or 220 volts) and the voltage coming out of the transformer (24 volts). You can take the transformer to your nearest U-FIX-IT store for free testing.

      Jim

  221. Steph n Dan says:

    AC unit keeps tripping breaker. If breaker is reset fan moves on AC unit slowly..as soon as I turn on the air on the thermostat the fan stops moving. The normal sound it makes when it ran before which I am assuming is the compressor is no longer running or at least does not sound like it. Then when that happens I check the breaker and it is no longer in the on position. Please help me figure out what is wrong…very tight budget and big family with kids and its only getting hotter outside. Thank you! PLease email me with suggestions.

    • Jim Plummer says:

      Steph n Dan,
      When the outdoor fan motor is moving slowly, the motor is bad. You can take your motor and capacitor to the nearest U-FIX-IT store for free testing. It may be a bad capacitor, but is probably a bad motor. A slow moving fan will draw excessive amps (and overheat) and it will cause the compressor to overheat. This motor and compressor combination is causing the circuit breaker to cut the power. Continuous operation of the compressor with a slow fan motor can cause the compressor to fail as well.

      Jim

  222. Jimmy Boyd says:

    Mr. Jim Plummer,

    Thank you for sharing your knowledge and experience with us (DYI non-professionals).

    Praise God for you. We’re grateful.

    I have a late model Maytag refrigerator that is not cooling and was told a connector module is needed that controls the compressor. Problem is my freezer nor the regular compartments cool.

    Please help!

    Thank you!

  223. Anthony says:

    Hi Jim,

    I have my home A/C unit start and running, but for about 1 minute, the fan stopped running and the compressor still running. Do you know what caused the problem?

    Thanks,

    -Anthony

  224. Yang says:

    Hai, I just bought 2.5 hp air cond for my living hall, but after the installer had done all the installation they turned on the aircond and I realize that there are no cool wind coming out from my aircond, its only totally fan. So I ask them to check the oitdoor unit and see wether its working or not. They find out that outdoor unit is not working at all. Either fan nor compressor is working. After the incident they also had tried 3 times come to my house and try to figure out something what was the problem that make my outdoor unit not working, bit the problem is up untill this moment I’m writing to you, my installer still fail to find what the cause of this problem. Hope you can help me for at least something here. Thanks Sir. Have a pleasant days ahead.

  225. Eleanor says:

    What is wrong with my refrigerator? Freezer works and fridge is not?

    • Jim Plummer says:

      Eleanor,

      Your symptoms, “freezor works and fridge is not” commonly occurs when there is a malfunction of the defrost system. Most refrigerators have a cooling coil in the freezer. The “fridge” or “fresh food” area gets it’s cold air as needed from the freezer. A malfunctioning defrost system can block passageways with ice. There are other malfunctions (depending on your exact model) that can produce these symptoms, however, this malfunction is easy to identify. Remove panels in the freezer covering the cooling coil. The defrost system malfunction is indicated if the coil is covered in ice (not frost). Call your nearest U-FIX-IT store for help in isolating the malfunction after you inspect your cooling coil and let us know what you find.

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