HVAC system not working

[maverickfhs]

Currently AC is not blowing cold air - verified filter, outdoor unit and blower inside are running.

Going to validate capacitors shortly, but usually a bad capacitor means outdoor unit won't run? Could it be a sealed system(requires 410a) issue?

Thanks for the pointers.

 

[BMWTurboDzl]

Is the evap coil iced up?

 

[KrisZ]

System leaks in home AC units are rare. I would try shutting it off for 10-15 minutes and re-starting. When the capacitor fails, the outdoor unit fan may be working, but the compressor won’t be on.

Once the whole thing is shut down for a while, it will probably not re-start if the capacitor is done for.

 

[maverickfhs]

Did not see any ice or signs of being frozen in that area?

 

[maverickfhs]

System leaks in home AC units are rare. I would try shutting it off for 10-15 minutes and re-starting. When the capacitor fails, the outdoor unit fan may be working, but the compressor won’t be on.

Once the whole thing is shut down for a while, it will probably not re-start if the capacitor is done for.

Have tried it a few times to see if it helps, no luck - it has been too.

 

[vwmaniaman]

Sounds like it lost its charge of coolant. Good luck finding a competent repairman. I have a homeowner policy on my sisters home and after 5 compressor replacements, I finally got a replacement with a seasoned repairman that knew what he was doing. It took him about 5 hours to replace the compressor correctly and pump the system down for hours and then charge it to the correct volume.

 

[Skippy722]

Is the compressor itself running or just the fan in the outside unit? Could have a bad compressor contactor or capacitor.

 

[maverickfhs]

Then probably will start simple, test contactor and capacitors.

There are two capacitors 40mfd and 6mfd, which one could be for the compressor? Can I replace with a dual one?

 

[alarmguy]

You say the outside unit is running. I think I and others in here are wondering if you are just talking about the fan on the outside unit and not the compressor.
Anyway, simple to check if you dont know what we are saying. Feel the low pressure side of the pipe going into the outside unit. The lower pressure pipe/tube is the big one.
The high pressure side is the thin one.
The low pressure side should be cold and sweating in most cases, if it feels air temperature warm chances are the compressor isnt running. Whether you are handy enough dont know but replace the Capacitor and the Contactor both cheap parts less that $100 for both.

If you are unsure what you are doing call a repair service.
(Edit)
Oops I see you know how to check the capacitor. To answer your question the capacitor serves two functions, one is for the fan unit and the other for the compressor built into the same unit. (oops, update, *LOL* figures you have two separate ones)
....When you replace it, assuming you know what you are doing, it doesnt hurt to replace the contactor while you are at it.

(For others it's very common for the Capacitor to be a dual function. One part of the capacitor is for the fan motor and the other part for the compressor. So you replace just one part. If you have two like the OP one will be bad and the other good but while you are in there you may as well replace both at the same time and know you will be good for years to come, same goes for the contactor.)

 

[bugeye]

40 is for the compressor

 

[maverickfhs]

You say the outside unit is running. I think I and others in here are wondering if you are just talking about the fan on the outside unit and not the compressor.
Anyway, simple to check if you dont know what we are saying. Feel the low pressure side of the pipe going into the outside unit. The lower pressure pipe/tube is the big one.
The high pressure side is the thin one.
The low pressure side should be cold and sweating in most cases, if it feels air temperature warm chances are the compressor isnt running. Whether you are handy enough dont know but replace the Capacitor and the Contactor both cheap parts less that $100 for both.

If you are unsure what you are doing call a repair service.
(Edit)
Oops I see you know how to check the capacitor. To answer your question the capacitor serves two functions, one is for the fan unit and the other for the compressor built into the same unit. (oops, update, *LOL* figures you have two separate ones)
....When you replace it, assuming you know what you are doing, it doesnt hurt to replace the contactor while you are at it.

(For others it's very common for the Capacitor to be a dual function. One part of the capacitor is for the fan motor and the other part for the compressor. So you replace just one part. If you have two like the OP one will be bad and the other good but while you are in there you may as well replace both at the same time and know you will be good for years to come, same goes for the contactor.)

Good and kind sir, appreciate your help. Will be testing shortly.

 

[maverickfhs]

40 is for the compressor

Thank you, can I replace with a dual to make sure both are replaced? Provided it is a capacitor.

 

[alarmguy]

Thank you, can I replace with a dual to make sure both are replaced? Provided it is a capacitor.

That I cant answer regarding the dual, I dont know, you would think you could but will need to research it or if you have a A/C supply house nearby maybe they or someone in here knows for sure. It wasnt even on my radar that there would be individual ones.

If you do a search on combining the two you will find a lot of info. Logically it would make sense that you can, after all its just whatever values are in play, I dont know if it would be worth the effort though or POSSIBLE wasted time vs a quick swap of the two.
Im a OEM type person, just so I dont get caught up in wasting time, possible size differences, brackets stuff like that. But you would know better, how much room you have and the set up.

 

[Highboy]

Then probably will start simple, test contactor and capacitors.

There are two capacitors 40mfd and 6mfd, which one could be for the compressor? Can I replace with a dual one?

Check the 40. If it’s puffed up or leaking it’s bad.

 

[Dave Sherman]

I lost the capacitor on my outdoor unit a couple years ago, and while the outdoor unit appeared to be running, you could tell the compressor just hummed loudly and didn't sound like it was running. Compressor was also getting a bit toasty inside its blanket. Checking the capacitance on my multimeter confirmed it was way off from the expected value, and the top of the can was bulging. New capacitor was $30 on Amazon and back to cooling the next day.

 

[maverickfhs]

Just kicked in the unit, vents are showing temperature is in 60's while outside is in mid 70's.

15-20 difference is not fully met?

 

[alarmguy]

Just kicked in the unit, vents are showing temperature is in 60's while outside is in mid 70's.

15-20 difference is not fully met?

Measure the temperature of the air inside the home at the air return duct and measure the temperature of the air coming out the vents.

 

[nomas]

You should have two copper lines outside going back into the house . With the unit running one of them should be cold and sweaty . IF the compressor is running and that line isn't cold , call the man .

 

[wag123]

If the problem is a bad capacitor (VERY common) and your outdoor unit has two of them, you are better off continuing to use two separate capacitors rather than one dual capacitor. The number one reason that capacitors fail is from heat. When you combine both capacitors in one can the heat buildup is higher than separate capacitors in separate cans and they are subject to fail sooner. On my home unit, when one side of my dual capacitor failed I replaced the dual capacitor with two single ones. I have not experienced one failure since but I do keep extras on hand (they are cheap) just in case.

 

[zzyzzx]

the top of the can was bulging.

That should be enough of an indication of a bad capacitor.