Air Conditioners Rattling Noise

If the air conditioner is making a rattling noise, there are several things you can check:

The front grille may be loose or broken. Remove the grille and inspect it to confirm it is not broken. If it is not broken, reinstall the grille. The instructions for removing and reinstalling the grille is in the Owner's Manual.
Check and clean the air filter. Debris and dirt from the exterior of the air conditioner should be removed.
The movable louvers are loose or broken. On some models, you can check and adjust the louvers. Consult your Owner's Manual for instructions.
With window units, improper installation can cause vibration in the window sill. Check the Installation Instructions for proper installation guidelines.

Note: If you hear a ticking or pinging noise, this may be from the slinger ring normal operation.