About a month or two ago our AC failed after a power restart during a storm. The next day I reset the breakers and the unit and we were good to go, a few days later the same issue. After poking around it looked like the AC unit fan was weak, after a push start it was up and we were good to go again. A few days after that, it stopped and started. So we got a new fan and installed it worked like a charm, wired it just like the old one. It's worked for two weeks just fine. We come home one day and it stops working. Try turning it on and I notice the fan does not kick on or anything, not even the buzzing/humming noise it usually made to start up.

So my smart idea was...lets reset the breaker again and see what happens. So I do so, and turn it on, and it was working! Fired up, was running full speed, then I noted it slowed down...was running at half speed for about 15 seconds...THEN BOOM!

It made a very loud sound, started smoking and sparking. I immediately shut it off and ran out of the way. It stopped smoking after a short while and it made a hissing noise...like a tired leaking air.

At this point its in a professionals hands. But what could have done this? It was running TWO weeks no problems. I'm starting to think someone's messing with my unit. The only thing different from before is I noted the air was blowing down into the unit and out the side. I thought this was wrong, as usually you want to blow the air through the sides and out the top. That's why I thought a two year old AC unit motor fan died. Did I mess up and the unit over-heated and blew up? Should the air go through the coils on the side and up and OUT of the unit?

What does this sound like...and does anyone have experience with AC unit warranties? This is my mother in law's home and she bought it less than two years ago, but had it installed by someone she knew. Do you need it installed by a manufacturer to receive any warranty work?

Thank you for ANY help and guidance.

 

In all likelihood, the original problem was probably just a bad fan capacitor (having to push it to start the fan is a classic sign of a bad capacitor). You're correct, the fan should be blowing the air up, not down. It's supposed to pull the outside air through the condenser coils and expel it out the top, cooling the compressor in the process.

Were you able to tell where the smoke and sparks were coming from (fan or compressor)? Since you said you heard a hissing noise, I'm guessing that it's likely the compressor (releasing refrigerant).

 

Could be a bad contactor, pitted or weak coil.

 

I forgot to mention, the very first thing we did was replace the capacitor with a new one. So it wasn't that which was the original issue with the fan. It has new capacitor and fan motor.

I don't think it was the fan where the smoke was coming from, it seemed like it was coming from further below. I can't recall where the sparks originated it could have been from the fan but I think they jumped out form the bottom as well. I did hear hissing which is the compressor I would think. I though maybe we put the fan the wrong way and the compressor was overheating and blew.

If it were a bad contactor, would it cause that pop and smoke? It was a really loud bang. The unit is less than two years old and shouldn't have these problems. I'm really curious if someone is fooling around with the unit, its on the side of the house and anyone can acces it, its facing the street, we live on a corner.

I have to head out and do a few things, I'll come back with what I notice when I take a closer look at the unit. Appreciate the responses so far.

 

A bad contactor can cause fireworks when trying to connect.

It sounds like a compressor failure. You'll need to check where the wiring connects to the compressor. Wear safety glasses anytime working around a possible compressor breach.

 

So...I figured out what it was, and I hate myself for it.

That plug I noticed that was unplugged, that was to the compressor...I took the AC apart and looked at it, it was dangling off not plugged into it.

It clearly states MAKE SURE AC IS OFF IF ITS UNPLUGGED.

I must have blown it when I tried to restart it and tripped the breaker.

I plugged it back in but it just starts and then dies. That hissing must have been the compressor blowing.

Heres what was wrong:



Learn from my mistakes, ALWAYS check your connections before turning on an AC unit. Could have saved myself a ton of trouble by taking a closer look. Is it possible there is foul play here, how could this have possibly come loose on its own?

I called a tech and they want 500 dollars to replace the compressor, is that fair, can I get a more competitive price?

 

Did he test the compressor? The warning label is just so you won't get shocked, no harm to the compressor if you pull it off with power on it. It would be like pulling the disconnect. If the $500 is just for labor that's a fair price.

 

The bang and following hiss was your compressor self destructing. It blew the plug off when it blew up, the hiss was the refrigerant coming out.

What most likely happened is your compressor overheated from the non working fan. It should have been protected by an internal overload cut out. Perhaps it cycled off that cut out once to many times.

Make sure whoever works on the system is made aware of the fan issue and corrects it or you might be back to square one again.

 

I guess the compressor could have overloaded when the fan wasn't working before, but the new one was working two weeks just fine. Is it likely the compressor already dying and its just time for it go? The fan was working perfectly for two weeks, so I'm just puzzled that it became too much for the compressor now.

 

The guy hasn't came yet to test it and look at it confirm its the compressor, but really could it be anything else? The motor looks good, and if it was responsible for the pop and smoke it'd look damaged/wouldn't spin at all I'd figure.