So I recently asked for suggestions on replacing my AC unit and got a lot of great advice that we aren't quite ready to use yet aka we don't have the money ready to replace our entire unit...

So the last 2 weeks sometime during the middle of the day when no one is home our AC fan shuts off and starts blowing hot air. The breaker isn't tripped but when I shut off the breaker outside and wait a few minutes and turn it back on the fan kicks right back on. Any reason this could be happening and NOT tripping the breaker?

It's frustrating but I'd rather not take out a loan to replace the unit if I can get another year out of it and pay cash for it.

Froze up?

Pump clogged up?

Do you have a spit system with an air handler in the attic? If so, your drain lines my be clogged and shutting the compressor off to keep your pan from over flowing and ruining your ceiling.

If you have this kind of system, wrap a rag around the end of your drain lines and use a shop vac to suck it out.

Mine did the same thing a bout a month ago. When the water level in the pan slowly drained down low enough, the float switch would allow the compressor to turn on and cool again until it filled back up.

I normally clean the periodically but just forgot to and they clogged up

Either froze up or compressor is getting hot. Weak relay on outside unit will make your fan kick in slower and pull less heat off the compressor.

Nothing frozen when I get home, but it could have shut off anytime during the day and thawed again. Not sure how to check that otherwise



Call me stupid. What pump could be clogged and how would I check that?

Split system with the handler in the crawl space. Drain line is free of clogs and draining when I check it. And it's weird when I flip the breaker off and then on it kicks on without any trouble. I'll check the contactor here in a minute and see if that tells me anything. Thanks so far, guys!

Is your system still blowing, just not the outside fan motor?

You got ants in your contacts. Lol

My guess. Low Freon causing the coil to freeze up over time and trip ambient control.

Buy a new one.

outside coil probably dirty causing high pressure switch to trip or compressor thermal protection to throw go to a supply house get some sodium hydroxide condenser coil cleaner mix it about 1:4 and soak the outside coil down real good with a pump up sprayer the whole coil should be covered with foam inside and out once you get it on thick enough and rinse it off after 4 or 5 minutes make sure you rinse good its corrosive stuff. you said the fan shuts off and blows hot air so im assuming you mean the compressor quits running because a fan cant blow anything if its shut off.

its called a capacitor and the outside unit doesnt have a relay it uses a contactor

If he can just flup it off and flip back on and it runs . Is bet the contracts are going bad bad . I have seen fire ants cause a problem .

No lie, this actually happened to ours once.

don't laugh at this...I had the EXACT same thing happen. turn breaker off (called HVAC dudes in the meantime) they came, and no chit..spiders were in the control panel. cleaned it out, works 4.0 now.

Yes. And it actually just cut off while I was home. Nothing is frozen and it still just starts right up like its supposed to if I turn breaker off/on. No ants around the unit and I removed the panel hiding the contactor and it tested fine with multi-meter. Well, it had about 237 volts instead of 240 but figured it was in range and the other side tested at 23.7.

Guess I'll have to call someone out cuzz I ain't coming home to an 86 degree house again.

Will try this. Fins are definitely visibly dirty, not filthy but I can see a thin layer of stuff on them but there are a lot of bent up fins, too. What tool would yall recommend to straighten them out or just call someone to do it and pay them?

one other thing we had happen...the sensor got an "over pressure" signal and shut off, had to be reset. I don't know jack chit about AC but they replaced the capacitor and cleared the over pressure alert. this was the second time I called Dallas Heating and Air...they're good folks by the way.

Capacitor, that's the word I was looking for. Mine went out last week and was doing exactly like his.