I have a weather king A/C heat pump. I purchased the unit (regrettably) and had it installed about a year ago. I've had the compressor replaced once after about six months. Unit worked fairly well after replacing the compressor. The supplier gave me a Copeland scroll-type comp which is has good reputation. Everything seemed to work fine afterward until this winter. Unit will run well during the day while the ambient temp is 50-65 degrees. However during the night when the temp drops to 20's and 30's the heat pump is louder than normal, but seems to be heating well. At around 5 - 6 a.m. (when it seems to be the coldest outside) the unit will stop blowing warm air and begin blowing cool air( not cold, just cool). The suction line at the air handler is cool (not cold) to the touch, but the compressor is still running. I will cut the unit off for about an hour and the heat pump begins working again until the next morning. I was thinking that it probably is a reversing valve or a RV coil problem. Not real sure though. I would certainly appreciate any input you might could provide.

Heating & Cooling - Weather King - 12AJA4801AH Air Conditioner