How to Fix / Troubleshooting

Safety first: Turn off power before inspecting moving parts.

Inspect fan area: Remove the top or side grille and check for sticks, stones, or other debris in the fan or coil area. Remove carefully.
Check fan blade tightness: Ensure the fan blade is securely fastened to the motor shaft. Tighten the set screw if loose.
Inspect motor bearings: Spin the fan by hand with power off. Roughness or play indicates worn bearings and the motor should be replaced.
Check compressor mounts: Look at the rubber mounts under the compressor. If cracked or missing, vibration will increase and mounts should be replaced.

Persistent grinding or metallic noises from the compressor itself indicate internal damage and require professional evaluation.

Heater is running but makes loud rattling or grinding noises

Possible Causes