I replaced the 7,100BTU AC on my popup with a 14,500BTU HEAT PUMP. It cools great, but the first time using it, the temperature at night got down to 55 degrees, so I tried the Heat Pump function and no heat just air at the inside ambient temperature. I am wondering why no heat. I have a heat pump on my house and it heats by itself to a 10 degree outside temp. So I know heat pumps work, especially at 55 degrees. The install is straight forward, and the controls on the inside panel plug into the outside unit. So no wiring problems. I am wondering if the reversing solenoid is not working or the reversing valve it self is stuck. I was hoping for some help before I end up taking it to the RV mechanic to diagnose an repair. I have only had the AC/HP on twice, that first trip and just this week in my driveway for two days (it is too hot for the heat function right now).