Dehumidifier powers on but compressor never starts; only fan runs

Safety: Unplug the unit. The compressor terminals carry mains voltage; only proceed if you are comfortable and experienced with electrical testing.

• Listen for clicks: When the unit calls for dehumidification, you should hear a click from the relay and a hum from the compressor. No sound may indicate a control or relay issue.
• Access compressor terminals: Remove the rear panel and compressor cover. Inspect the start relay and run capacitor for burn marks or bulging.
• Test capacitor: Use a capacitance meter to verify the capacitor value matches the rating. Replace if out of tolerance.
• Check relay: If the relay is a plug-on type, replace it with the correct Inventor compressor start relay.
• Winding test (advanced): With power disconnected, measure resistance between compressor terminals. Open or shorted windings indicate a failed compressor, which requires professional replacement.
• PCB control: If all compressor components test good, the main PCB may not be energizing the relay and should be replaced.