What It Means
- Thermostat demand signal Y1 is present, but the compressor is not running. Heat pump only - Trip light will be on during defrost board 5 minute delay with Y thermostat call.

Split & Multi-Split:
1 Compressor protector is open. 2 Outdoor unit power disconnect is open. 3 Compressor circuit breaker or fuse(s) is open. 4 Broken wire or connector is not making contact. 5 Low pressure switch open if present in the system. 6 Compressor contactor has failed to close.
Thermostat demand signal Y1 is present, but the com- pressor is not running. Heat pump only − Trip light will be on during defrost board 5 minute delay with Y thermostat call.
Continue in ACLogics with guided diagnosis for your equipment and symptoms.