Dear,
My Heat Pump has suddenly stopped working even though we set the thermostat in Heating mode. When I hit the contactor to test the compressor, it ran fine. So, there is obviously nothing wrong with the compressor. What are the possible causes of the problem? My stat is the Vision Pro 8000 and my Heat Pump is RUUD UPKB-048CAZ. The fan and the Air Filter of the Air Handling Unit are still in good condition. Thanks for your help. Brian Nguyen

The low voltage power is not getting to the contactor to activate it. Start by using a electric meter and tracing the low voltage power from the unit back to the inside unit.