Furnace rattles or vibrates loudly when running.

Safety first: Turn off power before tightening any internal components.

Step-by-step checks:

• 1. Tighten access panels: Ensure the burner and blower doors are properly seated and screws are tight. Add foam tape if panels rattle.
• 2. Check blower housing screws: Inspect and tighten screws securing the blower assembly to the furnace cabinet.
• 3. Verify furnace leveling: Use a level to check if the furnace is sitting evenly. Shim under the base if necessary to reduce vibration.
• 4. Inspect blower wheel: Look for missing fins or heavy dust buildup that could unbalance the wheel. Clean as needed.

When to call a professional: If vibration is severe or accompanied by unusual motor noises, a technician should inspect the blower wheel and motor for damage and replace with Philco-approved parts if needed.