Upon arrival we found a blown five amp fuse in the air handler. I replaced the fuse tested and cycled on emergency heat and it is working fine. We put the unit in heat pump mode and the unit failed at the thermostat. I manually cycled the heat pump and now it is operating properly. Due to the 20° outdoor temperature and recent power outages we’re leaving the unit in emergency heat temporarily. The homeowners care taker is going to put the unit back into heat pump mode once the weather warms up.