Dehumidifier powers on but compressor never starts; fan runs normally

Safety: Unplug the unit. The compressor circuit is high voltage; only proceed if comfortable with electrical testing.

Steps:

• Listen for relay click: When the unit calls for dehumidification, you should hear a click from the control board. No click may indicate a bad relay or control board.
• Inspect compressor wiring: Remove the compressor terminal cover and check that all spade connectors are tight and not burnt.
• Check overload protector: Test continuity through the compressor overload device. Replace if open.
• Measure compressor windings: With wires removed, measure resistance between compressor terminals. Open or shorted windings indicate a failed compressor.
• Replace control PCB: If the compressor and overload test good but never receive power, replace the main control PCB (which contains the compressor relay).