Top 5 Reasons Why Your Window AC Unit Is Noisy
Not all homes have central air conditioning. Some have window air conditioning units that are designed to cool one room, usually the bedroom, or a few rooms. A major complaint about these units is how much noise they make. If your window AC unit starts making more noise than it normally makes, there’s some common reasons why. For the seasoned DIY-er, these troubleshooting tips may help. If not, or if your window unit can’t be reached safely, call in the professionals.
1. Foreign Objects
If your window AC unit suddenly starts making a loud noise, a foreign object may have fallen into it. Flying debris (leaves, twigs, paper) or small animals can easily get stuck in the outer part (the part that hangs outside the window) of the AC unit. Lizards or mice might find your unit appealing enough to try to make their home or a hiding place when chased by a predator.
DIY: Turn off and unplug your AC unit. Open the front grill, and with a flashlight, inspect the inside of the unit. Remove any foreign objects and fasten the front grill back into place. Plug in and turn on the AC unit. Repeat steps if loud noise can still be heard.
2. Bent Fan Blades
Foreign objects can cause problems even after you’ve removed them. The fan blade(s) can become bent if the foreign object is strong enough to bend it.
DIY: Turn off and unplug your AC unit. Open the front grill, and with a flashlight, inspect the blades to see if any are bent. Straighten them by hand or with a pair of pliers.
3. Vibrations on Window Frame
In general, window-mounted AC units are heavy and have lots of moving parts. Also, they’re prone to a lot of vibration, especially if they were not mounted correctly to begin with.
DIY: While the unit is on, touch both sides of the window frame that house the unit. If you feel excessive vibrations, check with the people who installed the unit. They should be able to adjust the unit to minimize the vibrations.
4. Loose Front Grill
The front grill of a window AC unit should be removed for regular cleanings of the filter, but if it is not put back in place properly, a loose grill can vibrate and cause noise.
DIY: Turn off and unplug your AC unit. Remove the front grill and then set it back in place. If the locking mechanism on the grill has been damaged, it may need replacing to fix the noise problem.
5. Insufficient Lubrication
A fan motor that is not sufficiently lubricated may cause a persistent loud noise.
DIY: Turn off the AC unit to avoid further damaging the motor. Most fan motors are sealed, so a professional service technician should be called.