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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521 thoughts on “Common Air Conditioner Capacitor Failure Symptoms

  1. Edward

    Good man package unit the condenser fan runs for 30 min than shut off but fan motor was replaced and the dual capacitor and still it runs for 30 min then shuts off but compressor still running check voltage of motor when shuts off an still has voltage

    Reply
  2. Barry

    My window AC starting leaking inside about a week ago so I thought clogged drainage but it got worse so I took another look inside removing front panel and filter and it appears on one of the metal coils there is a bulge and comparing it to pipe connections above it and below it show no other bulge all other pipes fit into their seams I believe it is this one connection that is leaking, the AC unit is 3 or 4 years old and gets used 3 months each year, I have a picture of the pipe area but no don’t know if i can upload it, anyhow if it is this one metal part can that be fixed ? The until blows cold air just fine and the fan is working too, any help is appreciated and you have a good day.

    Reply
    1. thehvacguy Post author

      Leaking water? then there really shouldn’t be a pipe but maybe a tube that is clogged. Possibly debris from outside has clogged the exterior drain. Take a hose and rinse it out real good from the outside.

      Reply
  3. Hareharan

    we have a problem in our Window Air Conditioner , No power to the board ( i.e the power On Indication was not glowing, this is happened at night .when i checked in the morning it was OK and running good . At Night when i check the power supply I/C was OK till the terminals of the Air conditioner .would like to hear from any one that. what may be the cause. I am not an Air Conditioner mechanic. is this a cause of the capacitor degradation .

    Reply
    1. thehvacguy Post author

      We do not work on window units. You can replace them for about the same price as a repair will cost you.

      Reply
  4. Jennifer Stice

    About 11 days ago our upstairs unit stopped blowing cold air. Outside fan was still going on the unit. My husband turned it off and we waited about 6 hours. He turned it back on and it immediately started blowing cold air again. Now 11 days later, the cold air is gone. I have someone coming out tomorrow but I would like to get your opinion. What would make the unit stop working and then begin working again for 11 days and now not work again. We live in the Dallas/Fort Worth area in Texas, so it does get pretty hot, could the unit just be overloaded? I would really appreciate your guidance on this because I don’t want to pay for repairs not needed or someone take advantage of us. Thanks for your help!

    Reply
    1. thehvacguy Post author

      What this sounds like is the unit is icing up after running, and thaws after several hours of not running. You will need professional advice on why your unit is icing over. Probable causes 1) Leaking refrigerant, 2) dirty filter, 3) bad blower fan motor or capacitor, 4) refrigerant restriction, 5) Short in the electrical system. Or some other less common reason.

      Reply
      1. Jennifer stice

        Thanks for your opinion… I spoke with a man this morning and he immediately said sounds like you need a new compressor. What are your thoughts on that? Compressors are awfully expensive….

      2. thehvacguy Post author

        I guess I was missing some clarification on the original post. Air flow.

        Was the air blowing but not cold or was there no air coming through the vents? No air = frozen coil and I would lean towards a leak. Blowing air but not cold, it could be the compressor. But, a dead compressor is typically a system of something else severely wrong with the system. Compressors do not normally fail without a reason.

  5. nancyforeman

    I just paid air conditioning company 900 for amana circuit board replacement for 13 year old unit. This seems very high to me. Should I say something. They didn’t write down model number on ticket.

    Reply
    1. thehvacguy Post author

      As with any air conditioning repair, you should have pre-authorized the repair. Also you probably should have gotten another estimate before making a repair of that value. The dealer can charge what he needs to cover his overhead costs. Some companies that is pretty high. So rather than beat up the dealer for an opinion about the high price, next time just get more estimates.

      Reply
  6. Clarissa

    Got a brand new motor for my a/c unit and
    Service guy forgot to put the thermostat
    Back on unit will that burn out the new motor

    Thank You
    Very hot in West Texas

    Reply
  7. Jonny

    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 cleaning of the condenser coils. It made an odd sound(hard to describe not very loud or high pitch but different than the original sound) . Then the next day the fan stopped working. I replaced the Fan motor and capacitor(thinking that should do the trick) well no such luck. I checked the contactor and it seems to be getting the proper current/voltage( its a split/dual pole seems like each side is getting 120 volts) in fact everything seems to be getting the proper current/voltage. 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????

    Reply
  8. George Elkins

    I have a Split unit. The Indoor unit iced over. Blower fan not turning. I defrosted the unit by turning on the heat. Could the capacitor on the blower fan be the problem or the fan itself?

    Reply
      1. George Elkins

        Replaced motor in air handler. Old motor was one speed….did not note speed. New motor has low med and high. any suggestions on what speed to put it on. House is 2400 ft2 ranch full finished basement.

      2. thehvacguy Post author

        More information needed.what was the old motor rated at? Horse power, r.p.m.?
        What is the new motor specification? Rpm at low med high?

  9. Carlos Junca

    After changing the blower cap AC runs, noticed the furnace fan not blowing as afst as it used to, could it be the high speed relay at control board

    Reply
  10. Sixxstring

    Hello. I’m having a little problem with my ac. The temperature in the house will not reach what we have it set to. It will only reach 76 even when set lower during the day. This happened two years ago and we replaced the capacitor. It worked fine until a few weeks ago when it started getting to peak temps outside. I was wondering if it was the same problem again but this time the outside fan on the unit is spinning. Could it still be the capacitor? Last time the outside fan would not spin. I have cleaned the outside unit and changed out the air filter inside. Thoughts?

    Reply
  11. Dennis Delgado

    I live Florida, I rent a home and 6 months into rental the A/C stopped working one night. I called the landlord who in turn sends out a a/c company. After they got it started they me sign the work order. The capacitor was bad and they said it was cause the filter was not changed in 6 months. The owner wants me to pay the bill. Now the question; Can a dirty filter cause that capacitor to stop working and the unit is 11 years old?

    Reply
    1. thehvacguy Post author

      I’m not sure what the laws are in Florida for landlord tenant, but not changing the filter could make you liable for the condition of the unit. On the other hand, I cannot give you a confirmation one way or the other about the capacitor. Capacitors have various reasons for failure, high temp, shelf life, age, manufacturing defect, voltage spikes, etc. They go bad often and should be checked annually as part of the regular maintenance on the unit. To directly associate blame for the capacitor on dirty filters is quite a big leap and cannot be proven. On the other hand, in my state of North Carolina, unless it is specifically called out in the lease, the landlord is responsible for the maintenance and repair of the mechanical systems. This repair falls under that category. So it really depends on your landlord what he is going to do. You can fight it, but is it worth the small charge for the capacitor? It’s up to you two to work out the details. Check with your local tenant laws and regulations. They may give you more direction on how to handle this situation.

      Check out our web site for other articles and videos.
      http://www.alexhvac.com

      Reply
  12. Curt McCauley

    Can a faulty capacitor cause the compressor to over amp? I was at a friends house last night (without any tools, of course) and her condensor had thrown the inside breaker. I shut off the outside disconnect and reset the breaker. When I closed the disconnect, the fan started spinning and I could hear the compressor come on for what seemed like half a second, and then the breaker tripped. The compressor sounded “normal” for that half a second, so at least it is able to turn.
    I will be going back over there to do the repairs and I want to be sure I’m on the right track. I’ll have a tool or two with me, so I should be able to see what’s up with amp draw and all that stuff, but anything I can’t take care of tonight will make her sweat for another 24 hours. I would love to be able to change the cap and be done with it, but I can’t afford to buy parts she doesn’t need. Ugh. And I’m just helping her out, so the less time and energy I spend on this, the better.
    So what would you do, Mr. Thehvacguy? You’re going over there tonight with nothing but what you bring. You can’t buy anything you don’t need and you want it working tonight. What’s your approach?
    Thanks. I look forward to reading your reply.

    Reply
    1. thehvacguy Post author

      Sorry, it’s not going to work tonight. Your compressor is, more than likely, gone. The windings have either internally shorted to each other or to ground. Check the resistance on the windings and let me know the outcome. I have a feeling the repair will be a major repair. Good luck.

      Check out our web site for other articles and videos.
      http://www.alexhvac.com

      Reply
      1. Curt McCauley

        Yeah, you’re probably right. I was just hoping for the possibility of maybe the cap not helping it over that start-up hump.
        Believe it or not, it makes a lot more sense if you’re in denial. “But I don’t want it to be the compressor. I want it to be the capacitor!” That’s what I was thinking when I read your reply.
        Although I respect your knowledge and experience, and understand that there is a reason you’re in this business and I’m not, there’s still this tiny little part of me that will more than likely convince the rest of me to pick up a capacitor on the way home. And then after I install it, I’ll be mad at you for being right.
        I appreciate your quick reply and your willingness to share your knowledge with others.
        Have a good day, sir. I’ll let you know what I find out.

      2. Curt McCauley

        Hey The. Sometimes my clairvoyance frightens me. I was dead on with my prediction. And it’s even timestamped this time.
        So now I’m looking for an R-22 heat pump condenser. But we may have to go with an R-410 unit if it’s the only thing I can find. I know nothing about these new blends, but I understand that this 410 operates at higher pressures?
        But now I’m worried about the evaporator. I guess I need to get the make and model numbers before I start asking about that part.

        Thanks for your wisdom.

      3. thehvacguy Post author

        You cannot use a 410A condenser with an old R22A coil. The coil has to be changed to withstand the R410A pressures. However, you can get what they call a “DRY SHIP” R22 condenser and continue to use R22 for the time being. These will probably be phased out soon.

  13. Dave

    Hi Hvacguy,

    I noticed this morning that I had warm air blowing out of my vents. Walked outside to my unit and the fan wasn’t blowing but there was a slight buzzing noise. Looked like a capacitor issue. Hvac tech came out and said it’s a capacitor and contactor issue. Both replaced in 10 mins. Unit running great,cold air from vents, etc. Moments later, the breaker trips and one of the terminals on the contactor is burnt out. The hvac tech goes into defense mode and states that he thinks the condensor (compressor?) was bad all along. Starts pitching me a $5000 unit replacement and says there are no other options. It seems a little fishy and I’m wondering if he miswired and caused the condensor to burn out. Any tips are very welcome.

    Reply
    1. Dave

      I should also add that AFTER the breaker tripped, the external safety switch looked as if it was melted/damaged on each terminal. Before this happened, they looked completely normal.

      Reply
      1. thehvacguy Post author

        Yes that can happen with an electrical current spike. Loose connections or an internally shorted compressor can do that. If the compressor has shorted out, have an acid test done to see how bad the damage is. High acid content would mean the entire system has been contaminated. I typically recommend replacing the evaporator coil, condensing unit, and doing a strong flush of the pipes when this happens.

        Check out our web site for other articles and videos.
        http://www.alexhvac.com

    2. thehvacguy Post author

      It’s possible that the compressor is bad and did cause the original problem and it is also possible the technician did not connect the wires tight enough and could have caused the contactor to fail. determining a bad compressor is easy and can be documented with resistance readings. Ask him for the resistance readings on the windings. He can still bluff you, so I would get a second opinion. A $89 service fee is appropriate for a second opinion. depending on the scope of the new install, I cannot comment on if the $5000 price is good or bad. Only second opinions and your research into the rating of the contractor will give you confidence in the recommendation. Check with BBB, Yelp, Google, Angie’s List and Facebook customer reviews to see if the company is trustworthy.

      Check out our web site for other articles and videos.
      http://www.alexhvac.com

      Reply
  14. waitanotherday

    We rent a condo with an a/c unit that is installed in the attic space. Last summer, there was a clog and water began dripping into my condo. While repairing that issue, the technician informed the landlord that the capacitor needed to be replaced and a new thermostat installed (it has the original from 1999 that doesn’t work properly). The landlord opted not to make either of those repairs.

    The unit doesn’t seem to be cycling properly over the past few weeks. I notice it getting warmer in my condo and then realize the A/C isn’t running. I can hear a hissing-type noise coming from the unit, but oftentimes, it fails to turn on even if I lower the temperature. I live in Arizona, so the A/C normally runs quite a bit. We set the thermostat to what I think is 85 during the day, upper 70’s when home & awake, and 82 when going to bed (again, it’s an old non-digital thermostat that isn’t really working properly). There are many nights where it just isn’t kicking on at all and now the issue has starting happening during the day as well. It’s 100 degrees outside today and the A/C isn’t kicking on.

    Does this sound like a capacitor problem? Is it dangerous (fire hazard) to leave this problem unresolved? Lately, I’ve just been turning the unit off entirely when leaving because I’m afraid it’s a dangerous situation. If it was up to me, I would have replaced everything last year, but as I said, the landlord is resistant to spending the money to make the repair. Any advice is greatly appreciated.

    Reply
    1. thehvacguy Post author

      Rather than talking about the AC as it is not your property, lets talk about your lease position as a tenant. In my state there are landlord tenant laws that govern this situation. the landlord is required to provide adequate mechanical systems to the tenant. A faulty AC violates that law. As a result your lease can be broken and full deposit refunded if he does not repair the situation within a reasonable amount of time. One month is considered a reasonable maximum limit and anything beyond that is considered reasonable for terminating the lease with cause. But check your states laws governing landlord/tenant regulations to be sure what applies to your situation.

      Check out our web site for other articles and videos.
      http://www.alexhvac.com

      Reply
  15. Zap

    Quick question I had a bad capacitor original was a 55/5 and the service technician only had a 60/5 on the truck – what effect will this have o the system over the life of the unit? would it have been better to have a 50/5 cap installed? BTW the system is running fine with the 60/5 cap

    Reply
    1. thehvacguy Post author

      10% of a 55/5 is 60.5/5.5 this is within tolerance of the capacitor and probably the unit. But you are risking the slight change you might be adding additional force on the compressor motor and could shorten it’s life. That is why you should only use what the motor recommends.

      Check out our web site for other articles and videos.
      http://www.alexhvac.com

      Reply
  16. Kevin

    Question, I had my fan motor and Run Capacitor Replaced about 2 years ago and today (106 Degree’s) the AC unit started blowing warm air throughout the house. When I went outside the fan had stop running and was making a humming sound. Is the Run Capacitor or the Fan Motor most likely stop working. Thanks

    Reply
    1. thehvacguy Post author

      It could be both. Having a bad capacitor for any length of time can damage the motor and cause early failure. That is why we recommend annual maintenance where we check and replace weak capacitors early so the motors do not fail prematurely.

      Check out our web site for other articles and videos.
      http://www.alexhvac.com

      Reply
  17. alex

    hi i have a rheem seer 10.there seems to be a box where the electricity goes in that has a slot for a flat metal piece with a plastic grip handle.Its missing but it was there at one point and its needed to have power to go to the ac unit outside..anyone know what this is and if i can get a replacement. thanx

    Reply
  18. Josh

    Fan on outdoor unit was not spinning while blowing warm air threw vents on inside of home. Changed capacitor, it was obviously bad. Of course I turned breaker off before changing capacitor but did not turn power off to furnace inside. It’s a older unit with a dial thermostat. Ac worked fine after installing new capacitor but when it reaches desired temp does not seem to shut off. If I turn the temp on the dial above room temperature I do not here the click on the dial but it does shut off minutes later. Do I have a problem here? Did check the fuse on the panel on the inside furnace. Not blown. Is it the transformer?

    Reply
    1. thehvacguy Post author

      I got a mixed signal from you. Does it shut off or does it not shut off? A delay shutting off is normal in certain conditions. Typically if the unit only minutes before was turned on, the delay is to prevent short cycling.

      Check out our web site for other articles and videos.
      http://www.alexhvac.com

      Reply
      1. Josh

        Yes I was a little obscure describing it. Basically i don’t hear the click when I turn the temp on the thermostat above where the room temp is currently at. When the night before the capo toe went out I was. They are the old Mercury type thermostats and I know they need replaced but just didn’t seem like the thermostat would start malfunctioning the same day the capacitor went out.

      2. thehvacguy Post author

        The click will only happen when the spring inside the thermostat adjusts until the mercury moves to the other side.

        Check out our web site for other articles and videos.
        http://www.alexhvac.com

  19. Rob

    Hello HVAC Guy – some great information here. My scenario is as follows: 2.5 ton Kenmore Unit – a little over 10 years old. A few weeks ago the unit started intermittent cooling. First thought was to replace fan capacitor – done. Worked for a few days – then fan ran intermittently such that the compressor would shut down – again no cooling. Replaced the fan motor – cooling and compression ok. After five days – no cooling but fan runs properly. Freon levels are ok. Other thoughts – bad capacitor for compressor, bad relay or compressor is toast from too many over heat cycles. Most frustrating part, the unit was 37 days outside warranty when it failed – Sears not helpful :( Any thoughts on the next steps? Replace compressor capacitor, replace relay, replace compressor/entire outdoor unit? Any thoughts would be appreciated. Thanks very much :)

    Reply
  20. joe

    Hi HVAC Guy,
    So today I came home from work and noticed my air wasn’t blowing cold and the ac unit outside was not spinning after a little research I tried the “stick trick” and the motor started to spin freely. And as of right now the motor is still going strong only problem now is the ac is still not blowing cold out of the vents. Im hoping its just a bad capacitor. Thanks in advance for any help you can offer.

    Reply
      1. William

        I’m having a similar issue where neither the fan or compressor start but when I jump start the fan, it’s able to power up on its own. However, it doesn’t seem like the compressor ever starts. Is the most likely cause a bad capacitor? I just started having this issue yesterday and luckily it’s not too terribly hot this weekend; I was reading online and thought this could be the issue since the fan would not start up on the outside unit but didn’t realize that if the capacitor was bad, it could lead to both the fan and compressor not running.

  21. Casandra

    AC cooling, but fan outside spins for a minute or so then stops & starts buzzing. Just got back from vacation & not what we were looking forward to coming home & seeing. ..

    Reply
    1. thehvacguy Post author

      Yes it can be a real headache when this happens. Sorry to hear it happened right after your vacation.

      Reply
  22. Hot in Mississippi

    Hello, first I want to say that I’m amazed by your response rate. Incredible. I have a question. Can a bad indoor fan motor capacitor cause the fan motor to stop turning when its operational? Thank you.

    Reply
  23. Hot in Mississippi

    Hello, first I want to say that I’m amazed by your response rate. Incredible. I have a question. Can a bad indoor fan motor capacitor cause the fan motor to stop turning when its operational?

    Reply
    1. thehvacguy Post author

      Absolutely. And a weak capacitor can ruin a good fan motor. Having a properly rated and operational capacitor prevents early motor wear as well as creating the best operating conditions for the internal magnets.

      Check out our web site for other articles and videos.
      http://www.alexhvac.com

      Reply
  24. Jason The Hobbyist

    Rain was getting in the control section of our 5-year old Luxaire 3 ton. The dual cap terminals must have got wet several times over the years and the compressor terminal overheated and the wire melted off the connector. I was going to reconnect to the existing cap’s spade with a new terminal but noticed the plastic insulator melted, causing the terminal to look like it may be fairly close to shorting against the cap case. Instead of screwing with it and causing any other issues I replaced the dual 45+5 cap (with two separate ones as my match was not available, of course). Powered everything up fine and been running for 3 hours but as I went to put the cover back on noticed a sizzling sound coming from the compressor cap (the 45uf). It is cool to the touch and so are the leads. Is this normal for a brand new cap? Will it settle in and stop worrying about it? Could also be the contactor but I don’t think so as the noise is more of an arcing/sizzling sound rather than a 60 cycle buzz.

    ¤¤ Amazes me some units run on rooftops for 30 years, but not mine lol. Next time I’ll buy a Carrier. ¤¤

    Reply
    1. thehvacguy Post author

      No, sizzling is not normal. However, is the noise possibly coming from the contactor? sometimes they hum or rattle a bit. If the sizzling is coming from the capacitor, I would probably recommend replacing the wiring where possible as the wires may have been damaged from the previous incident.

      Reply
      1. Jason The Hobbyist

        Thanks. I forgot to mention I replaced the leads with new wires/spade connectors. Also measured both caps to be perfect uf before installing.

        The original factory wire would have been too short after removing the burned section. Unit is still running and cycling perfectly in this 34 deg C heat days later. Compressor and fan sound normal. If take the cover off and a sizzling noise is still present from the new cap, would a licensed tech gently apply pressure to the leads or contactor to determine where the noise may coming from? I know you can’t recommend doing anything dangerous so just wondering what a tech would do next. With my lack of experience I’m thinking of returning the new cap for a replacement in case this one is defective. But what are the chances a new cap is defective?

        Thanks for this forum. You’re a patient, patient man!

      2. thehvacguy Post author

        The new cap could be defective. The hissing may be a loose connection. Typically we would squeeze the spade connectors so that they fit snug and take a bit of pressure to fit down completely on the spade of the capacitor.

        Check out our web site for other articles and videos.
        http://www.alexhvac.com

  25. Pavel

    Hello, great blog. Quick question if you don’t mind. My inside blower motor stops working 3 times a season. I replace 7.5 mF running capacitor and it works again. The motor is 16 years old and started to have this problem about 4 years ago. I assume eventually the motor will go but do you know how long can it last like this? The blower locations doesn’t make it possible to replace the motor without breaking Sheetrock walls and the ceiling. Thank you in advance.

    Reply
    1. thehvacguy Post author

      You’re lucky it lasted as long as it did. The mechanical code in the US requires a level working space of 30in x 30 in in front of the control side to service an appliance. Rooms containing an appliance shall be provided with a door and an unobstructed passageway measuring not less than 36in wide and 80 in high, or large enough to fit the largest appliance in the space.

      From this reading, it sounds like your installation is in violation of the mechanical code in my state.

      Check out our web site for other articles and videos.
      http://www.alexhvac.com

      Reply
      1. Pavel

        Thank you for the quick response. It is what it is, when you are a first time home buyer, you miss a lot of things. Also, I guess I will get a split system when this one dies. The current one is still using freon which can’t be replaced anyway. Thanks again.

      2. thehvacguy Post author

        Freon is a Brand name and not actually tied to one particular formulation of refrigerant. They all use refrigerant (commonly referred to as Freon). They are just changing from R22 to R410 formulation. We are still adding R22 to older units but the prices are rising as supplies decrease.

  26. Mary

    Thank you for this blog! My question is about compresor capacitor install. Ours was replaced but the odd thing is that the technician insisted on connecting it outside the unit instead of opening it up and removing the old one. So it sits in the panel area and works. Embarassed to ask, but was this a mistake, should I have them install it “properly”?
    Thank you

    Reply
    1. thehvacguy Post author

      Just to be clear,, if it is outside the unit, and people are able to touch it without removing a cover or guard, call the cops on this guy. The capacitor is HIGH VOLTAGE and should be protected from accidental contact. If it is covered and behind a panel that must be unscrewed, then it is OK, but poor judgement by leaving the old one there.

      Reply
      1. thehvacguy Post author

        Don’t really call the cops. Call the company owner and if he doesn’t fix it, then call the licensing board and file a formal complaint.

      2. Mary

        Yes poor judgement indeed. In our haste I agreed, fortunately it is covered. However I am going to request they return and install it properly

  27. Julie

    Hi – we have a Lennox unit & it was making a horrible noise (roof mount)- the fan was not spinning is we replaced the capacitor. It’s now working just fine except now it vibrates. It’s quiet outside near the unit but in the bedroom below the unit, there is a loud vibrating sound. There was some play in the fan (going up & down)- could this be part of the vibration problem? Or can you think of another reason?

    Reply
    1. thehvacguy Post author

      It could be that the fan is now out of balance or someone left a screw out when the unit was last checked and the rattling is because something is no longer secured. The play in the fan is an indication the bearings are bad. This can happen when running on a bad capacitor for too long.

      Reply
  28. Fadi

    Hello.. my home AC was working properly this morning. The very same day at evening i turned it on and there was no cool air blowing.. just normal air
    The compressor seems to work normally and so the compressor fan (outdoor unit) also spinning flawlessly but it blows normal air (i think it must be hot) , all working as before but there is no cool air at all.
    I’m confused because a Freon leakage can not be developed in just several hours
    plus if the run capacitor is bad then why the compressor is running ?
    when i despaired .. i removed the plastic cap that housing the wiring on the outer unit so i can see the run capacitor , it was way way hot (the body of the capacitor) with a light burning smell . i stopped at this point and i think that i need a pro person to look into this problem.
    a side notice may be useful :Now when switching on the AC i hear a hissing noise from internal unit that lasts for about 10 seconds and then goes away , i thought it is normal cause i used to hear the same sound every time i switch the AC on when it used to cool very well ,but the hissing sound was taking about like 3 seconds or so (lesser time than it after the problem occurred)
    any thoughts ?
    .
    Thanks HVAC for hearing us
    PS: sorry for grammatical faults .

    Reply
    1. thehvacguy Post author

      A couple of things come to mind. The hissing noise usually is flash gas and is a sign that the compressor is running and you are low on freon. The hot capacitor is due to the location, function and high voltage running through it. It can also be going bad. That might explain why the unit is not blowing cold air all the time as it may not always keep the compressor running. The capacitor should be checked and replaced if weak because it will ruin your compressor. The leak you have may have grown by now and yes it can leak out fast enough to prevent you from feeling cool air. This now sounds like you will need to replace either the coil or the whole AC. I would lean to the whole unit since your compressor may have been negatively impacted by the low freon and the bad capacitor. If you replace the coil, you may find you need a new compressor within the next year if not sooner. Those two independent repairs will cost you almost the same as a new system but without any decent warranty. An annual maintenance program may have prevented this untimely problem. I always recommend an annual maintenance program to be sure the system is in its best conditions and improves the odds for a long life.

      Reply
      1. Fadi

        Thanks for responding.
        My AC unit is just one year old and sadly it is not under warranty. I’m sad to hear that I might need to replace the coil or the whole unit .
        cause the problem happened all of sudden and now i still can see/hear all the components running but the ac is not cooling at all . no frost on the pipes nor the evaporator and the pipes are not cold as it should be.

      2. Fadi

        Update :
        Had the unit checked by a technician .firstly he said it is completely out of Freon. charged it and immediately a resonable hissing sound came from the condenser, the area where the compressor located. He uninstalled the unit a took it to his workshop for investigation. Now it is confirmed that a sudden leakage took place , maybe due to weak pipes conjunction or so ?? . I hope that it is not the compressor.
        Thank you very much .

      3. Fadi

        Update 2 :
        Got it fixed !
        So a tiny pipe inside the unit come into contact with the compressor leg which due to vibration eroded with time and finally cracked ,That explains why the unit lost its refrigerant so fast. Thank you very much and have a cool day.

  29. Wilson Ziegenbein

    I changed out the fan delay relay board and the system again runs like its supposed to! Thank you for pointing me back to the boards to take a closer look. That brown toasty spot was way up on the top edge against the top of the control/wiring area compartment.

    Reply
  30. LG

    My AC unit got hit by power surge from lightning
    about 2 weeks ago, I have been without AC since with 90 degree temps my great ins company sent their expert out saying the capacitor blew and can be replaced

    My AC guy says replace the unit due to possible
    issues of other parts that may come up in a week
    month or so my unit was working fine before
    hit by lightning no repair company wants to touch
    it and be responsible for other parts that may
    go bad

    What are your thoughts?

    Reply
    1. thehvacguy Post author

      I would be upfront with you and give you your options. 1) You can replace the capacitor and see if that holds up for a while but be warned that there could be other damage and I would not warranty anything other than the part for 30 days. 2) Replace the system due to the possible unforeseen issues.
      But here’s your call, pay $150 to replace the capacitor or $5000 to replace the system. It seems obvious to me that the risk of $150 repair and it working, outweighs the $5000 repair that may not have been necessary. This is a decision only you can make. We can only offer the options.

      Reply
      1. LG

        My AC unit got hit by power surge from lightning
        about 2 weeks ago, I have been without AC since with 90 degree temps my great ins company sent their expert out saying the capacitor blew and can be replaced

        My AC guy says replace the unit due to possible
        issues of other parts that may come up in a week
        month or so my unit was working fine before
        hit by lightning no repair company wants to touch
        it and be responsible for other parts that may
        go bad

        What are your thoughts?

  31. Adam R

    Hi, I have a roof top packaged air/heat unit. The air comes out cold, but not very strong. So, it takes forever or never to bring down the house temperature and shut off. Could this be a problem with inside blower/fan? Bad capacitor? Thank you.

    Reply
    1. thehvacguy Post author

      Sounds like an air flow issue. Either your filters are clogged, ducts are crushed, or the system is low on freon (frozen coil).

      Reply
  32. Becky

    So I just had a general maintenance done on my home ac on Wednesday and then on Friday my ac went out. I called the company that did the service earlier in the week but they wouldnt come until monday. I called another company and they came out that day and it turns out the capacitor needed replacing. Is that something the guy should have seen 2 days earlier or do they really go out that quickly?

    Reply
    1. thehvacguy Post author

      Probably but not for sure. It the capacitor blew due to defect and/or high heat, then no. If the capacitor was below specification then yes the tech should have seen that. But it doesn’t always show bad right before it has an internal catastrophic failure.

      Reply
  33. Louie

    Hi hvac guy,

    I have a small trane condenser and the fan kicks on and everything is cooling. Within 5 min. The fan shuts down. Checked the barings and replaced the dual cap. Checked the filters. And the condenser still runs. Plz help.

    Reply
    1. thehvacguy Post author

      I am assuming the fan that shuts down is the outside condenser fan. Sounds like one of three things, bad capacitor, bad fan, or loose wire connection. If its a heat pump, then there is a chance you have a bad defrost board.

      Reply
  34. Wilson Ziegenbein

    We have been living with an intermittent shut down on the air handler for an American Standard package unit. First, during the winter we found that the blower would shut down and not restart in the auto mode. Going to always run, got us through the winter. Now that we have gotten to cooling season the blower is shutting down randomly even in always run mode. When it shuts down, the compressor and coil fan continue to run and the thermostat indicates ‘cool on’. If we turn off both breakers feeding the unit, wait a couple minutes, and turn them back on the blower comes back on, compressor follows and all is good. If it is really hot out it will stay running longer (days) before the blower shuts down, and when moderate temps(80) the time seems shorter (2 hours). There was obvious arcing going on at the main contactor, we changed that. Indoor thermostat was changed to rule that out. We had a tech come out before I started changing anything, he looked at the blower, it restarted when he just physically touched the outside of the casing, charged $75 and left. Would a bad capacitor cause this kind of fault? Or maybe a relay that won’t stay pulled in? Any ideas would be appreciated.

    Reply
    1. thehvacguy Post author

      Well this one is always tricky and would need someone to test all the circuits to find the one that is causing the problem. I would say it is either a loose wire connection or a bad circuit board. Good luck.

      Reply
      1. Wilson Ziegenbein

        So I took another look under the hood after work today…the time delay board is a nice white pcb…except for the area where it is brown around the area where R2 is…think maybe I found the problem with one or more components on that board getting a little toasty?

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