Unit powers on but compressor never starts; only fan runs and no cooling occurs.

Safety: Unplug the unit. Compressor circuits carry high voltage; advanced testing should be done by qualified personnel.

• Listen for compressor: When COOL is selected, listen for a deeper humming sound indicating compressor operation. If absent, proceed with checks.
• Inspect wiring: Access the compressor compartment and check all connectors to the compressor, overload protector, and start device for tightness and signs of overheating.
• Check capacitor/relay: If your model uses an external start capacitor or relay, inspect for bulging, leaking, or burn marks. Replace the compressor start capacitor or start relay if defective.
• Board output (advanced): With proper safety precautions, a technician can verify if the main PCB is sending power to the compressor terminals when cooling is commanded.
• Compressor test: If the compressor windings are open/shorted or the compressor is locked, it must be replaced by a licensed HVAC technician.