Furnace rattles or vibrates loudly when running.

Safety First: Turn off power before tightening screws or touching internal parts.

• Tighten panels: Check all access doors and side panels. Tighten screws and ensure latches are secure.
• Secure blower housing: Inspect mounting screws on the blower assembly and tighten any that are loose.
• Check furnace leveling: Ensure the furnace sits level on its base or platform. Shim if necessary to reduce vibration.
• Inspect blower wheel: Look for bent fins or heavy dust buildup causing imbalance. Clean carefully and replace if damaged.