Heat pump question

I have a Trane heat pump that was installed to replace the 20-year old one that died. This was installed just six months ago, and has been working perfectly, even in the 115 F. Arizona summer.

Yesterday, the outside unit suddenly made a loud noise for a few minutes, then it stopped. However, the fan then started to cycle on and off every few seconds. Oddly enough, the inside unit kept working, and it was putting out cold air.

I turned the system off for a while, then back on but it still kept on doing the on-and-off thing. As it had cooled down to about 106 F by then :smiley: I turned the system off for about 30 minutes.

Turned it back on, and the outside unit was working fine, steady as usual. I had called the A/C outfit that installed it, and they said they would get somebody up today

As it is working alright now, I called them back, and they said they could send somebody up this afternoon, but if it was working OK, there would be no way they could analyze what the trouble had been. Moreover, although the unit is still under full warranty, they said if there was indeed no way to see what caused the problem, they would have to charge an $88 service call

I told them to hold off and I would call if it started doing this again.

One thing of note: we had the carpet cleaner up yesterday who did all the carpets. After that, of course, all the carpet was very wet, and usually takes a long time to dry out. I can’t believe this had anything to do with it, especially as the other unit that cools the bedrooms kept on working without any problem.

So, finally, anybody have an idea what might have caused this?

What kind of loud noise did it make? Like a loud buzzing?
My first guess would be that the fan motor has a bad bearing, and it seized temporarily. This might also explain why it’s cycling - it overheats and the thermal shutdown activates.

It might also me a marginal motor-start capacitor.

Thanks, beowulff, a bearing sounds about right, but as long as it is working OK now, will just wait and see.

I did not hear the sound initially, but my wife describes it as a sort of loud whir and then a louder bang, that repeated a few times. It is difficult to describe a sound in print, maybe she should call you and do the sound orally. :smiley:

A bang could indicate that a fan blade hit something. I’d check it out when it’s not running and see if one of the blades is bent.

Specifically? No. But in general Trane has been noticeably dropping in quality since 2007, when a certain ‘venture capital’ company helped break up American Standard, with Trane eventually sold off to some overseas company.

Seriously, make good use of the warranty, you will need it.

Ingersoll Rand