I'm sure you have all seen "heat pump trips breaker" questions on here, but I have a slightly different question on the subject.
We moved into a new house this past summer. It is in a muni electric area in Upstate NY (cheap), so everything in the house is electric. The house was built in 1989. The furnace/air handler and HP are 13 years old. The furnace is a Rheem RHQA-1620J The HP is (I think) a Trane XE1000 with a model number of TWR042C100B2.
Anyway, here's the scenario... I'm coming from an old one-pipe steam system, so I don't know much about all electric heat pump systems... please bear with me.
No problems at all through the whole summer. Temps were quite high, and everything performed well.
When we got into the heating season (September), I noticed that there was (what I thought to be) a louder than normal buzzing coming from the HP. We inherited a well known local company's "Gold Seal" maintenance plan from the previous owners. I have decided to continue with it. Great deal and service. So I called them about the buzzing. They came out and determined that it was a bad coil on the reversing valve. Replaced in November along with the scheduled cleaning and maintenance.
In December the inside HP breaker started tripping intermittently. Company came out, found that the outside disconnect was broken down, and replaced. Each time they come, they run full diagnostics, and everything is within spec.
End of December, again, breaker is tripping. Nothing out of spec. I suggested as a long shot, possible weak breaker inside. Replaced. 40 amp breaker, same as before.
The breaker started tripping again, and I have found another interesting observance... It only seems to trip when the temperature is above freezing, like 35-40F. We have had some long stretches of 0-15F weather over the past few months, and the HP works flawlessly. No odd sounds, very little resistance heat strip use, etc. As long as the temps are below 30F the HP seems to run just fine, for weeks at a time. Now that it has warmed up to about 35-40F, I have reset the inside breaker three times just today.
I figured I would throw this out to the masses before I call the company again, and have them just tell me that everything is within spec and that the average life of a HP is 12 years in this area.
Thanks for your time.