Typically, your AC unit shouldn’t make much noise as it cools your home. If it starts making unusual sounds, something is amiss. Get to the root of the matter right away to avoid surges in your utility bills or loss of functionality. The following guide outlines what to keep an ear out for.

A Guide to Problematic AC Unit Noises

1. Hissing or Bubbling

Refrigerant is the substance that absorbs heat from indoor air to cool your home. This process is interrupted if it's allowed to escape through a hole in the system. Bubbling occurs when air enters the refrigerant line. Alternatively, hissing indicates the coolant is in its gaseous state as it leaks. Since refrigerant is hazardous to breathe in, get the problem checked immediately. 

AC unit

2. Rattling

If your AC sounds like someone is shaking the system, there is most likely a loose part responsible for the rattle. A screw or fan blade could be flailing around inside the unit. If the rattling is detected in the outdoor condenser, debris that's gotten inside could be the culprit. A technician can find where the disturbance is coming from and repair it. 

3. Squealing

A piercing squealing is not something you want to listen to as your air conditioning is running. Often, the compressor is responsible for this whine. Refrigerant flows through this part of the unit when it's in a gaseous state. A sensor in the compressor signals the AC unit to power off if pressure levels get too high, but there are instances when the sensor isn’t working. Squealing is the result of atypical pressure. Since this can be dangerous, turn the system off and call a professional to have it examined. 


If you notice your AC unit making any unusual noises, reach out to Donovan & Jorgenson. The company is available to help those residing in Greater Milwaukee, WI, offering expert maintenance and repair services, as well as 24/7 emergency aid for added convenience. Learn more about their offerings or schedule an appointment by visiting their website.