Unit vibrates excessively and may rattle the window frame or wall.

Safety: Ensure the unit is supported before loosening any mounting hardware.

Steps:

• Check level and support: Verify the unit is level side-to-side and slightly tilted to the outside. Ensure the window or wall sleeve is rigid and properly secured.
• Add padding: Install foam weatherstripping or vibration pads between the unit and window frame to dampen vibration.
• Inspect fan blade and blower: Look for bent blades or debris causing imbalance. Replace damaged fan blades or blower wheels.
• Tighten fasteners: Tighten all chassis and mounting screws.