Safety: Unplug the unit before adjusting installation or accessing internal parts.

Check leveling: Ensure the unit is level side-to-side and slightly tilted backward (window units) according to the manual.
Secure mounting: Tighten all mounting screws and brackets securing the unit to the window or wall. Add foam strips where the cabinet contacts the frame to dampen vibration.
Inspect blower and fan: Remove covers and check that the blower wheel and condenser fan are firmly attached to their shafts and not wobbling. Tighten set screws if loose.
Replace damaged parts: If the blower wheel or fan blade is warped or cracked, replace it with the correct Black+Decker part.

Unit vibrates excessively, causing the cabinet or window frame to shake.

Possible Causes