Loud rattling or vibrating noise when the unit is running, especially at higher fan speeds.

Safety first: Unplug the unit before inspecting moving parts. Fan blades can cause injury.

Steps to reduce noise and vibration:

• 1. Check installation: Ensure the Insignia AC is firmly supported in the window or wall sleeve and that side panels are tight. Use foam strips to fill gaps and reduce rattling.
• 2. Inspect blower wheel: Remove the front cover and look for foreign objects (plastic, leaves, screws) in the indoor blower wheel. Remove any debris.
• 3. Tighten screws: With the outer shell removed, tighten all accessible screws securing the fan motor, compressor mounts, and chassis panels.
• 4. Examine fan blades: Inspect the outdoor fan blade for cracks or bends. Replace the fan blade if damaged or badly out of balance.
• 5. Level the unit: Use a level to ensure the unit is not twisted or sagging, which can cause vibration. Adjust supports as needed.