I have a new Rheem heat pump. The cooling works fine but won't blow hot air in HEAT setting. I have reset the breakers for heat pump and air handler, changed filters and pulled batteries and reset the Braeburn 3000 thermostat. Still blows cold... Any other suggestions?

I know this is an oldie but it is a goodie. Can be the reversing valve is not engaging or is stuck part way. The reversing valve is what tells the refrigerant which way to go in heat or cool mode.

MANY techs don't know this but it is worth checking the freon charge out first to elimate that as the culprit. A low charged unit doesn't have the umphhhh to push the valve. Also I have swapped out many reversing valve solenoids first before changing the whole valve. The actual valve change is expensve and we hate to do it because of the location and complexities so I would try and save a buck and have these other two eliminated first.

Good luck