How To Repair A Noisy Air Conditioner

If your window air conditioner is making an unusual noise, the problem could be with the fan. In a properly working air conditioner, the motorized fan will pull air through the filter and over the cold evaporator coils and then re-circulate the cooled air back into the room. There is also a second fan on the motor shaft that cools the condenser coils at the back. If either fan blade is bent, damaged or has an accumulated dirt build-up on them that may cause an unbalance, they might make an unusual noise. Remove the cover and inspect the fan blades for any signs that they may be contacting the cabinet, fan housing or insulation and adjust if necessary. Remove any foreign objects that may have entered the cabinet and could be contacting the fan blades. If the blades are very dirty then you should also clean the evaporator and condensers coils and clean or replace the filter at the same time. Verify that the fan blades are not damaged or warped and that they are attached securely to the motor shaft and tighten or replace as necessary. On some models the condenser fan blade is also used to sling the condensate or drain water onto the condenser coils to increase the efficiency of the unit. If the unit is not installed properly or if the drain port is plugged or restricted, then there may be excessive water in the bottom of the unit causing a loud or unusual noise as the fan blade makes contact with it. Clear the obstruction or tilt the unit back to correct the symptom.

Most air conditioners use a double shaft fan motor with two fan blades, but some air conditioners use a squirrel cage style of blower wheel. If you have this style of fan and it is making an unusual noise, you may have a defective blower wheel/fan bearing. This type of blower normally has a drive motor attached to one end and is fitted into a stationary bearing at the opposite end. You will need to remove the cover to access the fan assembly. Detach the motor and blower wheel from the bearing to allow for easier replacement.

Window air conditioners normally use a double shaft fan motor with two separate blades attached. One blade is used for drawing air over the cold evaporator coil and re-circulating it into the room. The opposite end of the motor has a fan blade that is used to dissipate the heat from the condenser coil. When your air conditioner is on, the fan motor runs almost continually, and over time the motor bearings or bushings may wear out and develop an unusual squeaking, screeching or roaring noise. If the air filter is not cleaned or changed regularly, or in unusually dirty environments, the fan blades can accumulate dirt and become unbalanced which can cause premature wear to the motor. Most models use non serviceable motors and when they become noisy, they will need to be replaced. Verify that the fan blades are not damaged as well and replace them if necessary.

If your window air conditioner is making an unusual noise, the problem could be that one of the fan blades is loose. In most window air conditioners, there are two fan blades attached to the fan motor. One of the fan blades is used to draw air through the evaporator coil and to re-circulate the cooled air into the room. The other fan blade is used to help dissipate the heat from the condenser coil at the back. Both blades are attached to a double shaft fan motor and are often attached to the shaft with a spring type clamp. If the clamp is weak or damaged, it may not hold the hub of the fan blade securely to the motor shaft and the blade may wobble and vibrate creating an unusual noise. Remove the cabinet and check the clamps for a secure fit. Check the hub of the fan blade for any signs of damage as well and replace if necessary.