On arrival upstairs system cooling when told to heat. I found the thermostat not sending the correct signals to the zone board, and the zone board was sending a call for cooling when not receiving one. Highly recommend replacing thermostat and zone board. Found uv system out of tolerance and significant biological growth in supply plenum. Recommended iaq 200 uv system to address this by killing all biological growth in airflow. Recommended soft start kits to help protect and extend the life of both compressors. Customer declined all recommendations.