Air conditioners can make a variety of different noises. Some of these are harmless and are part of normal operation, but others can be quite concerning and signify a bigger issue. If you’ve noticed noises coming from the indoor or outdoor part of your air conditioner, it may be time for you to contact a professional for a tune-up. Here are some of the most common noises that might occur without proper annual maintenance.


If the outdoor part of your air conditioner unit, known as the compressor, makes a buzzing sound during normal operation, it could mean many different things. Most commonly, the buzz is coming from a loose part vibrating against the unit, debris caught inside the unit, a loose or failing fan motor, unbalanced or loose fan blades, vibrating or rubbing copper lines, or even a dirty condenser coil. During a tune-up, a technician will check for all of these issues and put a stop to the buzzing sound.

Rattling or Chattering

Rattling or chattering usually indicates a loose part that is rattling about or vibrating against another part. Oftentimes, these sounds come from older air conditioner units that have started to deteriorate over time, resulting in loose parts. Though you can check for loose screws on your air conditioner unit’s casing yourself, you should call a technician to perform a regular tune-up right away. He or she will check every part and connection for a tight fit while looking for issues that may cause you bigger problems later down the line.


A louder clanking sound is also indicative of a part that is either loose or out of balance, but in this case, the louder sound points toward parts inside the sealed part of the unit. It could be that your compressor has come loose, that your blower fan blades are out of balance, or a number of other problems. This sort of sound may occur suddenly, or it may worsen over time due to missed maintenance and service calls. A tune-up may resolve the issue, but if the sound is severe, it may require a repair.


Clicking sounds can occur for a few different reasons, and some are normal. For example, even a loud click is normal as the air conditioner first starts up, and if a leaf or twig falls into the outdoor compressor, the fan bouncing off the debris can make a clicking sound, as well. Though a tune-up certainly cannot prevent debris from falling into the compressor, it can help a technician catch other potential issues that could lead to bigger problems such as electrical issues or a part stuck in the blower fan blades.

An air conditioner tune-up involves a thorough inspection of each part of your unit, and when it is performed properly by a trained and licensed HVAC technician, you can rest assured that he or she has done everything possible to prevent future problems and noises. Often, these tune-ups are the best possible way to prevent noises like the ones above and extend the operating life of your air conditioner.