How to Fix an Air Conditioner Making Noise

An unusual noise coming from your window air conditioner could be caused by the fan. The fan pulls air through the filter and sends it over the evaporator coils to be cooled, before blowing the air back into your room. The motor shaft features an additional fan which helps cool the condenser coils as well. The unusual noise could be coming from either fan, especially if they have a bent blade, buildup of debris, or an imbalance. To check the fan blades, remove the fan cover and check for damage or foreign objects. You can also take this opportunity to clean the fan blades and condenser coils of any dust or dirt buildup. Inspect the fan filter as well to see if it needs changing. Some air conditioner models use the condenser fan blade to transfer excess drain water onto the condenser coils; if the drain port becomes clogged, the excess water can cause the unusual noise as the fan blades slosh through it. Drain the excess water and make sure the port is no longer plugged to clear up this problem.

If your air conditioner is making an unusual noise such as buzzing or humming, it may be a problem with the fan bearing, which is a component of the blower wheel in air conditioners that feature a squirrel cage-style blower wheel. Remove the fan cover to get to the fan assembly, then remove the blower wheel and motor in order to replace this part.

If your air conditioner is making an unusual, high-pitched squeaking noise, it could mean there is a problem with the fan motor. Window units typically have a double shaft fan motor with two fan blades which work in tandem to distribute cold air over the condenser coils. The fan motor bearings and/or bushings can become worn over time and cause the unusual noise. They can also become worn if the blower wheel is unbalanced, which happens when there is a buildup of dirt because the air filter has not been changed. When the fan motor becomes noisy on a window air conditioner unit, it means it needs to be replaced.

If you have a noisy air conditioner, the issue could simply be a loose fan blade. The two fan blades will normally be attached to the fan motor shaft with spring clamps. Remove the fan cover to inspect the clamp, to see if it has come loose or is damaged. If so, it could be causing a clunking noise. Replace the spring clamp if it shows signs of damage. Take this opportunity to also inspect the fan blades for damage and clean them off.