I have a Carrier heat pump. Outdoor unit is a model 38yka030300, indoor unit model
40yr030300. In December 2008, I installed a Honeywell VisionPRO TH8320U1008 thermostat. About two weeks ago, I came home one afternoon and it was in the 80's inside. I checked and the compressor was not running. The contactor was closed and was getting power across both sides. Pulled the fuse from the disconnect and the contactor still would not release. Tried to ope the contactor with a screw driver with the fuse out of the disconnect and when I let it go, it would close (make contact) immediately. I pulled the thermostat out of the base and the contactor opened. I left the thermostat out for about ten minutes to reset. Put the thermostat back on it's base and the compressor started and everything worked fine for about four days and the same thing happened again. Same situation with the contactor and thermostat. Happened again this weekend while we were gone.

Is it a bad thermostat or maybe a relay or something else in the compressor? What should and how should I check?

Thanks
Gary Allen
[email protected]
423-834-1792

The thermostat is wshat closes the contactor... not your outside disconect. I would start calling a tech out. Sounds to me like you have an issue with the compressor. Maybe overheating and going off on thermal protection, or a bad cap, or could be a combination of several things.

Better to get it checked and done right versus using a screwdriver and causing more issues.