How to Fix / Troubleshooting

Safety first: Turn off power before tightening or adjusting components.

Tighten panels: Check all furnace access panels and screws. Tighten any loose fasteners.
Inspect blower wheel: With power OFF, access the blower compartment and check that the blower wheel set screw is tight on the motor shaft.
Check motor bearings: Spin the blower wheel by hand. If you hear grinding or feel roughness, the motor bearings may be failing.
Secure venting: Inspect vent pipes and secure them with proper hangers to prevent rattling.

Persistent squealing or grinding usually indicates a failing blower motor that should be replaced.

Furnace is very noisy during operation; rattling, squealing, or grinding sounds from the unit.

Possible Causes