5 Reasons Your AC Is Making Banging Noises
Your home's air conditioner has a few normal sounds it makes, but it should never produce any type of banging or knocking noises. If you hear bangs and knocks, then it's time to get to the root of the problem.
1. Compressor Failure
Inside the compressor is several moving parts, including a bearing that keeps everything moving smoothly. If the bearing seizes or fails, or if a moving part in the compressor breaks and blocks moving, then loud banging sounds that are sometimes combined with a grinding noise may occur when the AC is operating. Repair typically means replacing the compressor.
2. Fan Problems
The blower fan rotates quite quickly, which means it must be properly balanced to move smoothly. If a fan blade breaks or bends, or if one of the controlling rods suffers damage, the out of balance fan can make a loud banging noise as it shakes and vibrates during rotation. Fan blades can be replaced or repaired, which solves the problem and puts an end to the banging noise.
3. Loose Housing
The housing on the exterior part of the unit is made to be easily removed for servicing and cleaning. If any of the screws or clips that hold the housing in place are loose or missing, then the housing may shake or bang when the blower and compressor are operating. Securing the housing back in place should stop the banging. You may need replacement screws or clips if any are missing or broken.
4. Vibration Issues
Vibration is a normal part of the operation, which is why your outdoor unit should be installed on a firm base that is equipped with anti-vibration pads. The pads absorb any vibrations so that the AC doesn't shake. If the pads are missing or worn out, or if the AC has somehow shifted off the pads, the vibration of the unit during operation can knock parts loose. The loose parts can then make a banging noise as they move around. Adjusting the unit or putting in new pads should stop the noise.
5. Trapped Debris
Debris gets into the outdoor unit through the various vents. Leaves, twigs, and other debris can then get blown around inside the AC and cause banging and scraping noises. For this reason, annual servicing that includes cleaning out the exterior unit should be part of the normal maintenance routine. This way you don't have to worry about noisy debris or any problems it may cause.
Contact an air conditioning service if you are concerned about the noise your AC is making.