I cycled the system for auxiliary heat (heat pump unit) and the system runs but the reversing valve will not energize for heat mode. There is no 24 volts coming from the thermostat to activate the reversing valve. I checked the wiring and it looks fine. The emergency heat works just fine. The thermostat would have to be replaced. She declined to replace it for now because she said the thermostat was replaced recently. She will check her records and use the emergency heat for now. *Customer used a $25 coupon for the service call *