Furnace vibrates excessively and causes rattling in ductwork when running.

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

• Tighten cabinet panels: Check all access doors and panels on the Miller furnace and tighten screws. Add foam tape where panels rattle.
• Inspect blower wheel: Remove the blower assembly and inspect the wheel for bent fins or debris. Clean and straighten minor bends; replace if severely damaged.
• Check mounting hardware: Ensure the blower housing and motor mounts are tight and properly aligned.
• Balance and support ducts: Add hangers or supports to vibrating duct sections and use flexible connectors if needed.