Upon arrival found system turned off. Turned on system at thermostat and unit came on and started cooling. I spoke with the customer customer stated that he turned on the heat for the first time last night. After examining the system and the heat pump I found no issues and determined that the reversing valve was sticking and had no other issues. I tested the unit in AC mode and heat mode and found it to be working properly. I verified with the customer that the system was pumping out 55° air and the upstairs had already dropped four degrees since I had it in Cooling. Found no other issues with the unit left system running and Cooling