Hi - Been a while since I posted here.
I am an HVAC contractor and am noticing a pattern with several R-410A compressors in (less than one year old) heat pump systems we've installed. After a cold night, I'll get a call from someone saying their outside unit is noisey and system is not heating.
What I see when I arrive is the compressor is running, but not pumping as pressures are equalized. Somehow the motor has 'de-coupled' from the mechanical assembly internally. It is not the same internal relief sound normally heard in R-22 based compressors.
Turning off the compressor for a day gives it time to cool down (or catch up with itself), then it operates normally again.
Anyone else experienced this? What causes this? Reversing valve sticking in mid-position? Long defrost cycle resulting in high head pressure?
BTW, these are Goodman units with Copeland scrolls. So far, have only seen this with 2.5 ton units.