Furnace vibrates excessively or rattles when running.

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

• 1. Check access panels: Ensure all Thermia furnace panels are properly seated and screws are tight. Add foam tape where panels vibrate.
• 2. Inspect blower wheel: Remove the blower assembly and check for debris stuck in the wheel. Clean thoroughly and ensure the wheel is centered on the motor shaft.
• 3. Secure ductwork: Inspect nearby ducts for loose hangers or joints. Tighten straps and add supports as needed.
• 4. Check inducer mounting: Verify that the inducer assembly is firmly mounted and not contacting the cabinet.