Common Air Conditioner Capacitor Failure Symptoms

Capacitor Failure Symptoms are sometime harder to identify without the right tools and expertise. Capacitors can be found in several different sizes and shapes. There may be one or multiple capacitors included in your ac with regards to the design. While the most popular capacitors are the types found on circuit boards, the ones most associated with air conditioning will be the bigger capacitors that assist start and run your motors. There are several motors present in an conditioner and heater systems:

  1. Compressor Motor Run Capacitor: Here is the most popular capacitor that fails. Most of the time these are duel capacitors, which means that there are 2 capacitors built into one. A duel capacitor will have three terminals on the top where a single capacitor will simply have two terminals on top.
  2. Outside Fan Motor Run Capacitor: That is the smaller capacitor found with or part of the Compressor Motor Capacitor. It helps start and run the outside fan that blows air through the outside coils.
  3. Indoor Blower Motor Run Capacitor: Similar to the outdoor fan motor capacitor, it is a small, single (two terminals) capacitor that will help start and run the indoor blower motor.
  4. Start Capacitor: Some models include an auxiliary start capacitor that helps jump start the motors. Most are found on the compressor. These are less common.

Why do capacitors go bad

When capacitors go south, they either go out entirely or they decline in strength. The decline is measured in the “capacitance” units called micro farads. When the capacitors are produced, they are labeled with their specifications capacitance and a range +/- from the design capacitance. This range is the allowable operating range, usually labeled in a percentage range, for the capacitor. If the capacitor starts to fail, the capacitance measured will be outside of the labeled range. Sometimes these are difficult to find any symptoms unless you have the proper tools. Warning, there is a risk of severe shock, so do not try this at home.

Diagnosing a bad capacitor

If a capacitor goes out completely, or is severely out of its operating range, it may prevent the motor affiliated with it from running completely. If the compressor motor is not working, then the air conditioner will not cool. If the outside fan is not working the compressor may cause problems and will short cycle or cease working. If the indoor fan stops, you’ll find that there is no air blowing through the vents.

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651 thoughts on “Common Air Conditioner Capacitor Failure Symptoms”

  1. Hello HVACGUY, I just turned my Ac Unit on after having it off for the Spring, after running for like 20 minutes my fan on my outdoor unit shuts off and the unit is making a humming sound. When I heard this I went inside and shut the unit off not wanting to cause any damage to anything. I waited about an hour and turned HP back on and it was cooling perfectly and same thing. I just replaced the capacitor about 6 months ago..Could this be the problem again? It doesn’t have a problem at start up but just shuts after a bit. Almost, acts the same as a winter defrost..

  2. Hello Good Sir. In the middle of the night we lost power. I chalked it up to a storm that came through, so I went to my breaker box and restored power. Then I lost power again to the whole house a half hour later. I turned off my AC and once again restored power. Trying to isolate the issue of an appliance, I left the AC off for 5 hours. All was good during that time until I flipped the AC back on. I looked outside and saw the fan was running on the condensor, air was blowing inside, yet 5 minutes later there was an noise like something was trying to turn on in the AC unit, and I again lost power to the whole house again. Any idea on this? I’m torn to either call a HVAC technician or an electrician because I don’t understand why the AC only doesn’t trip, but instead the whole house. Thank you!

    1. You may have two problems. Short internal to the compressor and a faulty breaker for the outside unit. It sounds like an overload that due to a faulty breaker defaults to the entire panel breaker causing the house to go out. Do not turn the breaker back on to the a.c. it may explode. Also the a.c. overload runs the risk of over heating the wires which can cause a house fire.

      Get both technician and electrician out the to check the compressor and the breaker.

  3. Hi
    I have a 8 Yr old Carrier 2T Split AC with Hermitically Sealed compressor.
    Below are the issues I am facing :-
    1. Indoor Unit Fan Capacitor 2.5mfd (Just like ceiling fan’s) goes bad within a few days. It had been changed by local AC mechanic. Now I don;t know what was rating of original capaictor. If anyone has any input for Cap rating, pl share asap.

    2. When AC Compressor is running, cooling is good. But it makes a hissing sound (in indoor unit) which doesn’t go away. Before Compressor comes on, the AC is silent. What could be making this hissing noise?
    Thanks

    1. I would need your model number of the indoor unit. Hissing sound could be a couple of things so I would need to locate the origin of the hiss more precisely.

  4. hi sir
    first i m yr great fan.
    my question is regarding overheating of compressor of outdoor unit …..
    my compressor gets overheated and s/w off after some time as the thermostat operates though the fan continues running at same speed. and fan speed is also good.
    i cleaned fins and coil but the problem persists again in a week.
    The ampere drawn by ac is also quite good only a little more like 0.4 amps i.e instead of 8.5 amps its 8.9 amps. also cooling is good when compressor is running. Usually the problem comes when outside temperature is more than 40 degree.
    During the cutoff of compressor it tend to start frequently in an interval of 7-10 minutes and starts only for 2-4 seconds and then s/w off.
    what may be possible cause please help me out.
    also when compressor runs it runs perfectly fine no unusual sound.
    can it be possible that overheating of compressor is due to its capacitor.
    hope i made my question very clear and thanks in advance……

    1. Sounds like the bearings are failing which is causing the overheating. Your higher amp draw is signalling this is the beginning of the end for the compressor.

  5. Hi Mr Alexander,

    The other day I noticed my compressor was running (hot to the touch), but the fan was not. I was able to kickstart the fan with a stick, so I figured the capacitor was bad; however a visual inspection didn’t reveal any signs of distress and when I tested it, the capacitor for the fan was within spec (5 mF), but the capacitor for the compressor was not (26 mF, whereas it should have been 30 mF +/- 6%). I then reinstalled the old capacitor thinking that it wasn’t the problem, but now neither the fan nor the compressor will run. In your opinion, would a weak compressor capacitor cause the fan to go out or is the fan motor bad? PS – the fan motor rotates freely.

    Thanks,
    David

    1. Sounds like the capacitor is a problem so replace it anyway. Now that you have removed it and nothing runs there appears to be other possible issues. Without putting a meter on the items, I would be only guessing at this point. Better call a technician.

  6. Last year my systems blower capacitor was bad. It had been bad but randomly working at times. The entire top popped off when it finally quit working.

    Now this year I’ve noticed massive air leak that seems to be coming under the unit at the back side below where the duct connects. It is indeed coming from under the entire unit. Have no idea why.

    I stuffed that leak with installation until I can disassemble the unit.

    On top of all that today it’s now blowing hot air. And my inside lights flicker I can hear the units fan kinda seize and same time my lights flicker. I have shut the unit off but hoping it’s just the capacitor.

    I have no idea what I’m doing but I’m going to try and fix it myself.

  7. Hi. I’m trying to decide between a bad fan motor or bad dual capacitor that’s causing the condenser unit to shut down. When the ac system is turned on, initially, the fan motor is engaged but the fan would not spin. I can sometimes see it trying to spin, but most of the time it’s still. I would then use a stick to help spin the fan, which worked quite easily the first few times. However, since then, it got harder and harder to get the fan to spin with a stick until I couldn’t do it anymore. The fan moves somewhat freely with a stick IF the motor is NOT engaged. But when the motor is engaged, it is hard to spin the fan with a stick because of the resistance. Is this normal operation of the fan motor? Secondly, is this a bad motor or a bad capacitor? I took the capacitor out and had it tested by a guy at Grainger and he said it was good. But, could that be wrong somehow, or maybe it only fails when it heats up during operation? Please help!!
    Thank you.
    Viet

    1. Sounds like you have ruled out the capacitor. It also appears to be the motor. One way to check is measure the amp draw.

      1. Can a bad capacitor cause the fan motor to draw too much or too little amps? Or does the capacitor has nothing to do with how much amps the fan motor draws?
        Thank you.

      2. A bad capacitor can make the motor draw too many amps because without a proper working capacitor the motor wears out faster. But the main reason it is drawing more amps is because the bearings have started to go bad due to running with a bad capacitor for too long.

  8. Hi HVACGUY, I’ve got a 4 ton Frigidaire package unit, and starting a few weeks ago when it rains, my (inside) blower will come on and run for no reason then go off after 4 or 5 minutes. This happens over and over even when the outside unit is not running and will also do this with the thermostat set to off. After rain is gone and dries out, unit works perfect. I’ve replaced the thermostat and same thing happens. I’m wondering if I have a bad thermostat wire. What do you think? Thanks

  9. Hello,we have a 1 ton Lloyd split AC without a stabiliser which worked fine for a year and past one week few times the indoor AC Has restarted on its own like on off on off then automatically it goes off and after 5 minutes it starts again and now the problem disappeared for a day then again the same automatic on and off. I have checked with my electrician there are no electrical problems. What could be the issue AC Technicians are also confused.

    1. Dispute what your electrician says, it is electrical in nature. It just isn’t the house wiring. It is something in the low voltage wiring, either a short in the wires or a control that is bad. This will take a lot of time to diagnose. Basically it involves diconnecting almost all the low voltage wires and checking each wire and control independently. It is not easy and a big challenge for most technicians. Ask for one who is highly skilled in low voltage problems.

      1. To add more details the technians are not that responsible and skilled. I have tried to find somebody to fix this but no luck . Do you think setting up a brand new voltage stabiliser would solve the problem or is it something already damaged in the AC INDOOR unit?

        I also noticed foul smell something not exactly burning smell but non recognisable smell from the AC

      2. Keep looking for a highly skilled technician. There are some that can solve this very quickly. And of course there are others who are just parts changers. Find the right one. It needs hands and eyes on to solve.

      3. I have spoken to a dozen today and all of them feel it’s a circuit issue. I’m just skeptical of changing the circuit as it’s just 14 months old AC. Do you think it could be a circuit problem with the indoor unit

    2. Hello again . An update on my issue . Got a brand new circuit installed a brand new 4kv strabliszer worked fine for a week and BAM. The ac switches off on its own again . Any idea ? What’s up with this issue

  10. Hi HVCA Guy, I have an issue of insufficient cooling with my 1.5T split AC (samsung).

    Last summer we faced low cooling issues. The fan was running slow and the compressor is talking hell of lot of time to cool the room to 24 deg C. That chilly cooling effect is missing altogether. So the technician was called to examine. He found the duel capacitance has gone bad and replaced it. Simultaneously the external voltage stabilizer too is found bad giving as much as 300 V output and got it repaired.

    Cooling is slightly better with this but the chilling effect is not there and the room is quickly heating up. The indoor blower is working fine and it seems the outdoor fan is also working fine. What’s wrong, why the cooling is insufficient, not known. The gas is at optimum level as per technician but, he says, the gas is normally a bit sticky but this in this case very dry, not sticky at all. That may be the issue, the entire gas need be replaced. I am not convinced and put a hold on that.

    High voltage output from the stabilizer is one thing in my mind. But dont know whether this could damage any part of AC other than capacitance. Can you help me in figuring out the problem?

    Thanks

    1. Unfortunately we don’t deal with the European currents. The system will be slightly different than the US but enough that I cannot give you any information that would help. You really need to get a second opinion from another technician if you think the first one is leading you wrong.

  11. Hi
    Maybe you will be able to help me out.
    I have a York heat pump. Noticed the heat continues after the desired tempature is met in the interior of my home. The indoor air handler continues blowing warm air , while the outdoor unit is off. The indoor unit dosent shut off even when set to off on my Robertshaw thermostat. To solve the problem i shut the main power breaker to the unit in my breaker box. After 5 min i turn it back on and everything works great… For about 6-8. Hours , then it happens again.
    I have a HVac guy coming over soon, but would like to have an idea how to aproche the next step.
    Any info will help
    Thanks.

    1. It could be a bad circuit board, switch, or wiring. Those are the most likely but not all possible root causes.

  12. Hello sir,
    I am having LG split AC , now the problem is when I start the AC, it turns on then while compressor is turning on MCB is tripped. Can u tell me the issue involved in this.. Please…

    1. It probably means the compressor is working too hard. Check the filters, coils, and if that is clean, have a tech check the refrigerant levels and the compressor amps.

  13. Hello,
    I just got done helping my mother move into her new home. While we were moving her stuff in her ac was on and working. But she didn’t like the old thermostat and had me replace it with a programmable one. I replaced it with a model that was not compatible so I put her old one back on and now it will not work? I checked and reset all of the breakers, even the one in the inside unit. Is this a sign that the outside capacitor has gone bad or is there something else I’ve broken lol. Please let me know. Thank you and God bless, Angel.

    1. You probably blew the 3amp fuse in the furnace or air handler. You should have turned off the breaker before you changed the thermostat.

  14. Hey HVAC guy! I live in a 13 year old apartment complex and maintanance had my outside fan motor replaced now my fan is working again. Unfortunately when i turned on my air it blew for about a minute and then cut off again they assured me that everything was fixed but now I’m back at square one and its hot again. Is there instructions that i have to follow after getting this type of work done that i wasnt told about? The fan outside is blowing but me ac is not staying on. Please help!!

    1. Sounds to me like you need to go back to management and tell them it’s still not working. Don’t take no for an answer.

  15. Got a trane package unit, 2007 model. Heat and air work, indoor fan blower motor started to work intermittent. Replaced the capacitor and it started right up and worked for a day like normal. The got a blower motor, teplaced it and started right up, everything seems normal on day one. If this doesnt last… what is usually the next part that goes bad? Circuit board, transformer, etc?? Outdoor fan and compressor seem normal.

  16. Hi, I’m having an issue with our indoor blower motor. We initially diagnosed it as a capacitor issue as it wasn’t starting at all, and making clicking noises. We replaced the capacitor and now, it will run for maybe 5-10 minutes. This is happening when we are only running the fan, so the heat is off (we were trying to isolate what the problem is). What do you think is the most likely issue? We’re hoping it’s not the motor itself… The circuit isn’t indicating any issues via the blinking LED light. Thanks for your help, please!

    1. Sounds like the bearings are bad and the motor is overheating. The internal overload protection is stopping the motor. Sounds like you ran the motor too long without a good capacitor.

  17. Hello,
    I have an Amana model # VHC36C2B. Not sure how old it is. We bought house 3 years ago but it was built in 98.
    I noticed the heat was on, but very old. After on for awhile it got warm. So I checked to see if the heat pump outside was on & it was NOT. So I checked the breaker & it was tripped. Then I went outside to heat pump & there is a humming noise coming from inside it. I reset the breaker back to “on”. The heat pump then started making a clicking noise like trying to start. It did this several times then tripped the breaker again. So we just turned thermostat to emergency heat.
    Several days have went by now. So today hoping for better outcome, I thought I would try it again. I turned thermostat to off. Reset breaker to “on”. Then turned thermostat to “heat”. The outside unit came on & steam came out of it but ran maybe 3-4 seconds & tripped the breaker & shut off.
    I was so hopeful when it actually came on but it didn’t last long. Do you know what could be causing this or where we need to start with testing?
    Thanks for your help.

    1. Unfortunately your compressor has got what is called “locked rotor” and is drawing amps that exceed the LRA rating on the motor. This is causing the breaker to trip. I highly recommend you DO NOT reset the breaker again. It is extremely dangerous. Call an HVAC Tech to validate the compressor is bad and get options for replacing the compressor, replacing the entire condensing unit and if the unit is over 12 years, replacing the entire system. Any way you look at it, the fix is going to be expensive.

      1. Thanks for the quick reply. I researched the serial # on unit & it was made in April 2004. Since the unit attempted to run before tripping breaker, would a hard start kit help or is the compressor done?

      2. It might help, but only for a short period of time. It would depend on how bad the bearings are gone.

      3. Our heating system now has R-22 in it. I see the new heat pumps have R-410A. Can the heating equipment located under the house be changed to the new type or does it all have to be replaced?

      4. It depends. If it is a package unit, no. If it is the outside condensing unit for a split system, no. If it is the air handler, it depends on the model number. If the air handler can handle r410a, then it needs to be flushed out and the metering device must be changed.

    2. After going outside to the unit, I realized that it was probably snow blowing out of it off the fan & not steam. As the unit & fan blades have snow on them.

  18. Hi,

    When the heat comes on in my house, the outdoor heat pump unit kicks on like normal and the fan inside of it runs at the normal speed. Maybe about 10 minutes or so into running, the fan will slow down significantly but continue to turn. During this time, the air handler inside continues to run and it appears as though it’s heating normally. Then after about another 5-10 minutes, the heat pump fan will go back to normal speed for a little awhile before turning off when the desired temp is reached.

    Is this normal behavior or do I possible have a bad capacitor? Thank you.

  19. Hello,

    My outdoor unit fan has a rough time starting. It’s noisy and sometimes doesn’t completely start. And will shut off for a few minutes and then try and start up again. We have replaced the capacitor once last summer and it worked great up until last week. It is showing the same symptoms as before. Could I have gotten a cheap/bad capacitor. Or do you think there is another underlying issues.

      1. The back of the fan motor does get unusually hot. I would expect that this could be an indication of a bad motor. If this is the case would you suggest a particular brand to replace it with. We will be renting this home out in the next few months and I would like to minimize the amount of repair calls we need to make.

  20. Hi. I have a rather unknown brand air conditioner….Chigo 24 btu……it blows out air, when set for cold air, but after a few minutes, the air becomes hotter. I cannot hear the compressor kicking in. There is 2 capasitors in the compressor

  21. It started in the summer….on air mode, the unit would stop and you could hear a humming noise. We noticed that air was not moving through the vents. We called a local air conditioner service and they ran all of their tests and concluded that it was just extremely hot and was freezing up. Everything checked out ok. So we left it at that. In the fall we turned the fan on only. The same thing happened. We called the same company back out and were told that we needed a new blower motor. My father in law inspected everything (who is handy with electrical/mechanical stuff) and said all of the motors were fine, everything is reading fine, etc. He placed a new starter capacitor. It worked fine for a month or so. Now it’s winter and it’s doing the same thing again. It runs short cycles and then it just stops. You can hear the compressor coming on and off, but that’s all. It’s not continuous. It may run just fine all day long and then start at night. Looking for a second opinion as I’m getting different suggestions!! Of course it NEVER acts up while anyone is here to witness it, other than myself.

    1. This is a tough one. So let me start with asking to check the blower motor capacitor. If within specification, and I mean what the motor requires and that matches the spec for the capacitor and the capacitor measures in that spec, then the motor is suspect. However, intermittent issues are usually circuit boards or wiring issues. Those are very difficult to diagnose and require on site testing and monitoring for signs of disconnects or shorts or jumping between wires. Not easy at all so please be patient with the technician on this one. The first company definitely didn’t give you sufficient advice. Freezing up is a symptom of larger problems. Air flow issues or freon issues. Not something to brush off as a small problem that can be solved by thawing it out.
      My recommendation is to get a second opinion with a reputable company that will invest the time to figure out a very difficult diagnosis.

      1. It seems to be very difficult to figure out since it is intermittent. It’s 6 years old and it’s never acted this way until this year. Thank you for your advice. Will def. look into another company.

      2. Hey HVAC guy. I was reading the Heather inquiry and wondered if now that it’s winter, is she STILL running the air conditioner, or is she now running the heater? Obviously, if she is running the heater then her issues would be totally different. My apologies for poking my nose in here, and if I’m off base, don’t hesitate to let me know, lol.

      3. Hi Foster, Good question.
        I highly doubt she is running the air conditioner. The blower fan is common for both heat and air conditioning. In the AC mode it runs on High speed. In Heat mode it is usually run at a much lower speed and is more susceptible to bearing issues because it has less force to get started in slow speed. Bearing problems can go unnoticed in AC mode then become prominent in heat mode. Bearing problems can be a result of running the system too long on a weak or dead capacitor.

  22. I have a 5 yr. old Broan 4 ton 15 seer Ultra High Efficient heat pump package unit. This summer in Florida was miserable. In the spring, the electric bills kept going higher every month. In Aug. our bill was $350, the highest ever. The house sometimes got as high as 84, humid and unbearable. We have had 3 companies come out. The unit was cleaned a few times, a weak capacitor replaced, the thermostat replaced, the Freon tested OK, compressor amps RLA 21.1-actual tested 11.0, Fan amps RLA 5.3-actual tested 2.7.
    The last tech said the unit TD is 19 degrees after measuring the air coming out of the inside vent. He couldn’t find anything wrong & wrote down the unit is running fine. It’s not. Last month, (Nov.), my bill was using twice the amount of kwts. from last year, the bill 3 times the amount from last year. Today, 12/26/15, the outside temp was 84 and the inside was 80. The unit then froze up, so we turned it off.
    I don’t know what to do. We’ve spent hundreds and no one seems to know the problem. I’ve spent hours on internet research, and am wondering if the board has gone bad. It’s a 2 stage A/C. It doesn’t seem like it’s kicking into the 2nd stage.
    I can’t face another horrible summer like last, and the electric bills are really hurting. I am a senior and fully expected this unit to outlast me. The company I purchased it from is out of business. The unit supposedly has a 10 yr. warranty, but service calls and labor costs are high, plus no one can find the problem.
    I would greatly appreciate any advice you might give.
    Thanks for your time,
    Karen

  23. Hi. My Honeywell thermostat is flashing cool on constantly and the fan in the outside unit is only spinning at about 1/2 the speed it normally does and the house is t cooling. Any ideas what might be wrong?

    1. The flashing cool means it is in a delay cycle. It shouldn’t do that constantly. The fan outside may be the problem. Since it isn’t running full speed the compressor may be over heating and shutting down. That is not good. Either the capacitor or the fan motor or both are bad. But you need to call someone who can test each piece to see what the true problem is and offer you a solution.

  24. Question. I had my unit ‘maintained’ recently with my biannual maintenance. The tech indicated that the capacitor on my blower fan was outputting less voltage than is called for (I don’t remember the numbers). Will a capacitor that is slowly ‘wearing out’ cause the fan to work at a lower rate thereby reducing the amount of air blown through the ductwork? I ask that because I have a home warranty contract that will pay for a new capacitor (if it fails), and/or a new fan blower (if it fails). It just won’t do it while it’s faiLING. In other words I’m wondering if it makes sense for me to replace it at my cost NOW, or let the warranty handle it LATER. Of course, the implication is that if there is no degradation in performance until it fails, why bother?

    1. Here is the thing, replaci,g the capacitor now increases the probability that your fan motor will last longer. Allowing the fan to run with a bad capacitor will significantly reduce the life of the motor. If it fails during a rather busy time may mean you wait for service several days. I recommend replacing the capacitor and help postpone the blower motor replacement.

      1. Thanks for the reply. It makes sense. Just a little question, though. Does a failing capacitor equate to a slower fan? In other words will my output thru the registers change as the capacitor fails, or is it a situation where the blower either works or doesn’t work in response to a failing capacitor?

      2. No you will not notice but the damage is definitely being done to the fan motor. It will just suddenly stop working.

  25. Hi,

    I just moved into a house and it has a Bard vertical wall mount ac (W24h1). We turned on the AC last night and we heard the outside turn on for about 5-10 seconds and then it kicked back off, air continued to blow out of the inside vents for 30 minutes but the air never cooled down. We turned off the AC and turned it back on 30 minutes later and the same thing happened.

    Any idea where we should start?

    1. You need to call a technician. I would need a lot more information and readings from the electrical to determine a possible problem.

  26. Hey hvac guy, I have an older carrier unit approx 16 yrs old. just recently the blower is blowing fuses twice in the last year and the outside unit has blown a capacitor. I just replaced the fuse in the blower about two months ago and now just today the blower blows a fuse after about a min or so of replacing it. Any suggestions on where to start to look.

    1. You have a short in your low voltage circuit. It could be anywhere, internal to a cable, a control, a loose wire, thermostat, circuit boards, wire harness. Better call a technician to determine where. Otherwise you will be guessing and just swapping parts. A time consuming search is necessary.

  27. The blower is buzzing to beat the band. I believe the capacitor is the culprit. I have noticed lately it took longer for the blower to spin up to speed so it was just a matter of time. Does that sound about right?

    1. It depends. If you have a variable speed blower, you do not have a capacitor. But if it is a PSC motor, then it sounds like the bearings are bad.

  28. Wonderful site ! I have a 20 year 2 1/2 tonTrane HP system with 2 stage electric heat. In heating mode the inside unit will short cycle. I moved the stat down the hallway away from the foyer (this is an upstairs unit) thinking that the return is pulling warm air from below. The fan will run if set to “on” and not shut off, so I think the blower motor is OK. The outside unit does not come on when it short cycles.The length of time is several minutes at most that is cycles. I set the heat differentials to their maximum. I was told that the electric heat is causing the blower to come on the blow off the excessive heat that built up in the heat coils. But the cycling continues until the unit is call to provide heat. Any help will allow me a good nights sleep.

    1. Sounds to me that you have maybe one or more problems going on. First you say the outside unit does not come on. That is one problem. It can cause the short cycling if the outside unit isnt providing stage 1 heat. The reason that the outside unit isnt coming on can be a variety of reasons. You will need a experienced technician to take a look. Moving the thermostat was not necessary. You probably also notice that the inside temperature isnt coming up all the way to the set point. The thermostat (as it should) is telling the heat strips to come on when the differential is more than 2 degrees Fahrenheit from the set temp. So when it is 3 or more, the stage 2 heat strips are coming on and “quickly” bringing the room temperature up to within 2 degrees of set temp and then turning off. Thus the short cycling. At the same time, you are burning up a lot of electricity because you are not getting the benefit of the heat pump from the outside unit. Solving that problem will resolve most of the other issues.

  29. The outside ac unit will start but the fan does not turn. Now our house isn’t circulating any cold air. Is it my compassitor?

    1. Sorry, not enough info to give a definitive answer. Three most likely causes are a bad blower capacitor, a bad blower motor, a bad fan switch/circuit board.

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