Central Air won't start - what gives?

[brigden]

It's too humid today, so I decided to crank up the AC. I go to the thermostat and select "cool," and set the temp to just below 20. Normally, I'd hear the fans come on. No dice. I change the fan selection from "auto" to "on." No dice.

Am I missing something?

 

[DAGTA]

It might be out of coolant. The AC I had in my duplex a few years ago was that way. Had some kind of trigger to not turn on if the coolant was empty.

 

[brigden]

How does one check? Does one need to do this seasonally?

 

[richardycc]

did you check all the fuse/breakers? including the one near the compressor outside? Don't just do a visual check, you might want to turn them off and on to give them a good solid contact again.

 

[dartworth]

HVAC TALK is a good forum

What kind of system is it?

Is this an all in one unit in an aprtment, or do you have a condenser sitting outside your house?

If the unnit is outside, I would check the disconnect box, which may be fused or unfused. Check to see if you have poser going to the box, and out of the box to the unit.

 

[Eli]

Originally posted by: richardycc
did you check all the fuse/breakers? including the one near the compressor outside? Don't just do a visual check, you might want to turn them off and on to give them a good solid contact again.

My guess too.

 

[tranceport]

I have a switch like a light switch on mine which I can turn the whole thing off for vactions and such.. maybe you have one also?

 

[brigden]

It's an outdoor unit, under our deck. I just had my roommate check it out with me, and we can hear a "ping" sorta sound when we turn it on, but no fan movement.

 

[Zenmervolt]

My guess is low refridgerant. If it's older, then it's an R-22 system and R-22 excels at finding leaks. In colder winters the seals shrink a bit and the R-22 can leak out, but in the summer when everything expands again, the leaks stop so the HVAC guys can't find the leak.

ZV

 

[dartworth]

Originally posted by: brigden
It's an outdoor unit, under our deck. I just had my roommate check it out with me, and we can hear a "ping" sorta sound when we turn it on, but no fan movement.

Open the unit up and give the compressor a couple of good wacks with a hammer...

It may be froze up, and needs a little help...

 

[Eli]

Originally posted by: dartworth

Originally posted by: brigden
It's an outdoor unit, under our deck. I just had my roommate check it out with me, and we can hear a "ping" sorta sound when we turn it on, but no fan movement.

Open the unit up and give the compressor a couple of good wacks with a hammer...

It may be froze up, and needs a little help...

If it is frozen up, he probably has more issues than a couple of wacks with a hammer is going to solve.. lol

 

[brigden]

Guys, I feel like a tit - I just had a look at the breaker panel and some twat had turned the breaker to off.

 

[dartworth]

Originally posted by: Eli

Originally posted by: dartworth

Originally posted by: brigden
It's an outdoor unit, under our deck. I just had my roommate check it out with me, and we can hear a "ping" sorta sound when we turn it on, but no fan movement.

Open the unit up and give the compressor a couple of good wacks with a hammer...

It may be froze up, and needs a little help...

If it is frozen up, he probably has more issues than a couple of wacks with a hammer is going to solve.. lol

You would be surprised. I've seen it work before

A relay or the hard start capacitor may be shot also...did you check to see if the compresser is hot?

 

[dartworth]

Yes, you are a tit...

FWIW...when troubleshoting, always check incoming power first

 

[brigden]

Originally posted by: dartworth
Yes, you are a tit...

FWIW...when troubleshoting, always check incoming power first

I always check ATOT first.

 

[Eli]

Originally posted by: brigden

Originally posted by: dartworth
Yes, you are a tit...

FWIW...when troubleshoting, always check incoming power first

I always check ATOT first.

LOL... :beer:

 

[grrl]

Originally posted by: Zenmervolt
My guess is low refridgerant. If it's older, then it's an R-22 system and R-22 excels at finding leaks. In colder winters the seals shrink a bit and the R-22 can leak out, but in the summer when everything expands again, the leaks stop so the HVAC guys can't find the leak.

ZV

What are you talking about? Seals shrinking? I spent 7 years in the HVAC trade and never had seals or O-rings shrink.

Always try the most obvious stuff first, like breakers or fuses. If you are talking about he outdoor fan not turning, it may be because there is a fan cycling switch. The fan only turns on when the head pressure is high enough. It all depends upon how cool the ambient air is and how hot it is in you house or apartment.