Heat pump problem?

[Barnacle_Bill]

A couple nights ago I noticed that the compressor outside was not kicking on. I didn't even sound like it was trying. Fortunately the aux strips in the air exchanger are working so we are not freezing to death. The next morning when I got up everything was working fine until now. Its doing it again. I had a bad starting capacitor a while back and a new one fixed that but at least that time I could tell it was trying to kick in. Could the cap be going again? Any suggestions? Its going to be hard to get a tech out here for a day or 2 due the holidays.

 

[joed]

Re: Heat pump problem?

It could be the OAT sensing it is too cold outside and bypassing the compressor in favor of the heat strips.

 

[hrdwrkingacguy]

Re: Heat pump problem?

Need to know a lot more about your setup to be able to make any kind of diagnosis from here...If you OFM was running and the compressor wasn't I would say, bad starting component is where to start(or a open IP in the compressor)...What tells your resistance heaters to come on and why? A lot of times the heaters are wired to X2 in the outdoor unit on a heat pump that turns them on when the unit goes into defrost, or when an outside air sensor says its to cold to run a heat pump like joed said...That could be a mechanical switch you can see or it could be built into the unit...It would be on the schematic and listed in the legend if it was a factory option...

The thing I would check when it isn't running but is supposed to be is, is the contactor pulled in and is there 24v from Y to C in the condenser...If there isn't then the unit isn't calling for the compressor...

 

[Barnacle_Bill]

Re: Heat pump problem?

I went out to take the access panel off and as soon as I just touched the box it started working. Weird.. I found 1 slightly loose wire going to the contactor. Also the contacts look a little burn't. Its hard to tell without taking it clear out. Fortunately it uses a cheap one and I'll go ahead and replace it as soon as I can get one (when the stores open back up). Does that sound like I'm on the right track?

 

[hrdwrkingacguy]

Re: Heat pump problem?

Its not going to be a bad contactor, loose wire mabey, bad solder on the control board mabey...You need to figure out what happened when it started...Was it a coincidence that it started up the second you took off the panel or did you move something that was loose...Follow the Y circuit on the schematic to figure it out...

 

[Barnacle_Bill]

Re: Heat pump problem?

Its hard to fix something that isn't broke. Like I said it started up when I "touched" the box and I did find one slightly loose wire going to the contactor. Its been running ever since I tightened the wire. It does have contacts in it similar to a solenoid and they do burn over time. If it does go bad neither the fan or the compressor will run which mine was doing. It did go bad once before years ago.

 

[hrdwrkingacguy]

Re: Heat pump problem?

Burnt contacts cause resistance, resistance causes heat, and heat makes contactors burn the contacts off...The coil though is either good or bad...Its an inductive load...When its energized it will try to pull in if its good, or sit there with power to the coil and do nothing if its bad...That's what I mean by I doubt its a contactor(not doubting its bad, just doubting its your problem with the unit not running)...

This is why pros are pros, I spend a lot of time trying to figure out why something that is good now, is going to go bad after I leave and head it off...