How to Fix / Troubleshooting

Safety: Unplug the unit before inspecting moving parts.

Steps:

Check for debris: Remove front grille and inspect the blower wheel for foreign objects. Remove any found.
Tighten hardware: Check screws securing the fan motor, blower housing, and outer shell. Tighten any loose fasteners.
Inspect fan blades: For the outdoor fan, remove the rear cover and check that the blade is firmly attached to the motor shaft and not cracked. Tighten the set screw or replace the fan blade if damaged.
Motor bearings: Spin the blower and fan by hand. Rough or noisy rotation indicates worn bearings; replace the indoor or condenser fan motor as needed.

Test: Reassemble and run the unit to confirm noise reduction.

Unit makes loud rattling, buzzing, or grinding noises during operation.

Possible Causes