Why does my AC stop working, then start working again?

I have an outside air conditioner. a few weeks ago it stopped putting out cold air, even though it was running. I turned it off. The next morning I turned it back on and it worked again. Last night it did the same thing, I turned it off and now today it is working again.

Could the outside intake be clogged?

Sounds like the condensor is freezing, and when you left it off all night, it thawed, thereby working again.

By “outside air conditioner” I’ll presume that you mean an outside condensing unit which is mated with an interior evaporator coil and air handling unit? If instead you mean the external unit of an air-source heat pump, we’re on a different page.

When you say “it” was running, please define “it”. Exterior condensing unit fan, unit compressor? Interior air handling unit fan?

Yeah, I’d bet the condensor froze up.

My does that sometimes.

So how to fix it?

It’s a big cube with a giant fan inside. also I don’t know if it matters but last night when it failed it rained really heavy almost all night.

It’s the evaporator inside the house that freezes. Water from humidity in the air condenses on the cold coils and can freeze. If there is enough moisture, the frozen water will block the airflow.

To melt the ice, turn off the A/C. Wait a couple of minutes, then turn on the heat for 5 - 10 minutes. Turn the heat off, wait a couples of minutes, then turn the A/C back on.

As the A/C runs it will dehumidify the air so that it should stop freezing up, unless you frequently open the doors or windows and let more humid air in.

There as=re a lot of different problems that can cause this problem. My not so WAG would be that the compressor is overheating and shutting off on internal overload. After it has been off for a while and cooled down, it works again for a period of time. This could be caused by high outside temperature and a partially clogged condenser coil. Has it been cleaned recently, or ever? It could also be caused by a failing condenser fan motor. It’s bearings are worn, it overheats and shuts down, then the compressor overheats as well. The fan may well restart long before the compressor will. There’s also a possibility of a high pressure safety shutting down the compressor. Some of these require a manual reset, some reset automatically, and some require the unit to be turned off and back on again to reset. Also, the compressor itself could be failing and this is just the warning before complete meltdown (figuratively speaking).

You’ll need to have the unit checked out by a professional to really know what is going on. If you don’t already know a reputable firm, ask your friends and neighbors who you should and should not call. Don’t just pick the largest ad from the yellow pages. Those ads are very expensive and sometimes the companies who purchase them are only interested in getting as much out of you as possible and not building up repeat business from satisfied customers. OTOH, if the company with the largest ad also comes highly recommended to you by friends and neighbors, it’s probably OK.

But first check to see if your condenser coil needs to be cleaned. It’s the car radiator looking part of the cube with the giant fan inside it. :smiley: