Does the Buzzing Noise From My AC Unit Mean It Needs to be Repaired?

Ideally, our air conditioning units should operate in relative silence. Older units, however, tend to make a bit of noise, and the same can be said for units that have not had regular maintenance checks. In all, all air conditioners are going to make some manner of noise, but sometimes it can be hard to tell which type of noise is normal and which is not. In the event that what you are hearing is a loud buzzing noise, it may be a sign that something in your AC unit is not working as it should be and could be one of the following common problems.




Even though air conditioning units see the most usage during the hottest times of the year, they are still subject at times to freezing, particularly if they are being used nonstop for long periods of time and are in need of maintenance or a cleaning. Shutting them off for an hour or so can solve the problem if that is in fact the issue, however, It is highly recommended not to run the unit until it has been looked at by one of our technicians.  Freezing can also be due to a refrigerant leak, which in turn can lead to that annoying buzzing noise. In the event that it is a refrigerant leak, it is also highly recommended to call us to get professional assistance in order to get the problem fixed. Running the system that is dirty or that has a leak is not only costly, it can cause serious damage to the equipment.


Loose Internal Parts


Obviously, there is a lot of working parts inside an AC unit, and at times one or more of those parts may become loose. When that happens, it can lead to other parts wearing down, causing that strange buzzing noise and over time, more serious malfunctions.


Problems With the Isolation Feet


Most all air conditioning units are mounted to a compressor located at the base of the overall unit. This compressor sits on small rubber feet, referred to isolation feet. Isolation feet will usually wear down over time which involves the rubber either cracking or eroding away. When the isolation feet are damaged, the air conditioning unit becomes unbalanced, which results in a buzzing sound.


Compressor/Electrical Issues


The compressor is the workhorse of an air conditioning unit, as it both cools and pressurizes the refrigerant. A buzzing sound could indicate that something is wrong with the compressor itself. Additionally, that type of sound often indicates an electrical issue, usually one of the following:


  • Circuit breakers
  • Electrical connections between any component
  • Condenser fan motor – the condenser fan motor is the big fan blowing from the outside whenever your AC unit is running. If the internal blower is running but the fan isn’t turning, the buzzing sound is likely the fan motor. Loose parts, fan failure, and debris on the inside can all be reasons for fan motor issues.
  • Contactor relay switch – The contactor relay switch is one of the most common types of electrical issues experienced with AC units. When the switch fails, it results in a loud buzzing noise.



Whenever you hear an unfamiliar buzzing noise coming from your AC unit, it is a good idea to call Weather Tech in order to take a look. Untended problems can quickly grow into bigger problems, so it is best to take care of them as quickly as possible.