B. If there is 24 volts at the transformer, check the thermostat and the wiring circuit going to the reversing valve. 3. If there is 24 volts present and the solenoid is intact, place a knife blade or ...

The difference is the position of the reversing valve that reverses refrigerant flow. 1. Setting the thermostat to the heat mode automatically powers the solenoid valve in the reversing valve. 2. The ...