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What to do About a Noisy Air Conditioner

Air conditioner noises can be a major source of nuisance. As one of the largest energy consuming devices in a home, they have the potential to be incredibly loud. The quickest solution – turning it off – results in discomfort from the heat, meaning the owner must pick their poison. Air conditioner noises have a variety of causes and can signal problems in different parts of the system. Below are a few of the most common causes of A/C noises.

Dirt and Debris

Rattling, clicking, or similar noises could just be the result of dirt or debris being sucked into the unit. Before worrying about whether a costly A/C repair will be needed, turn off the unit. When doing this, make sure that it is actually powered off and not just off because of the thermostat to avoid unexpected restarting and possible injury. Check to make sure all ducts, air filters, and the outside air intake are clean and free of any nearby loose objects that could be within the path of the air flow and create a potential noise source. After this is done, make sure all covers and filters are tightly in place to avoid rattling noises.


Older air conditioner units were built to different standards, are generally less efficient, and do not have the noise reduction technology of newer units. Someone who moves into a home with an older air conditioner may notice that it runs loudly, but this does not mean it is not running as it has from the day it was installed. Unless a sudden increase in noise is noticed, it is probably running normally and the decision to replace it is a purely economic one.

Undersized Ducts

A popping noise when the air conditioner is turned on or off is a sign that the air ducts in a home are not properly sized. The sound comes from the air pushing the ducts outward when it is first pumped through and when air stops and the ducts collapse back to their natural width. Undersized ducts mean the air is unable to flow freely, similar to water running through a pinched hose, and that the air conditioner is using additional energy by cooling air it isn’t able to deliver and by staying on longer because less delivered air means more time to cool. The only fix for this is to replace the ducts.

Mechanical Issues

Some noises may signify a major problem, especially loud clanking and banging noises that begin suddenly. These types of noises can be a sign that a compressor, fan, or other major part is about to fail. They should be checked promptly because if the cause is not one of the ones listed above, a part could break and damage other parts, stress the rest of the system, or create a fire hazard.

Your HVAC & Plumbing Unlimited A/C repair specialists in Centreville, VA, are always available to handle any air conditioning issues. They can perform routine maintenance, determine the cause of any problems, and recommend a course of action including no action, minor repairs, or total replacement. Call us today, our friendly staff will be happy to answer your questions.

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