What Do the Sounds Coming From Your A/C Unit Mean?

What Do the Sounds Coming From Your AC Unit Mean?

When your a/c unit is humming along in good shape, it’s almost soundless—which can make clanks, hisses, squeals, and buzzes coming from your unit all the more alarming. What do these sounds mean, and is repair possible? Learn about the various noises your a/c unit can make and how you can fix them.

Squealing Sounds

A high-pitched squealing noise coming from your unit is usually a sign of a belt or bearings issue. Narrowing this problem down usually involves assessing your a/c’s age. In older a/c units, the motor is connected to the blower fan with a belt. If this belt slips, it can make an extremely loud squealing noise much like a car or truck with a serpentine belt issue. Fortunately, replacing this belt can be a simple fix.

On the other hand, if your a/c is relatively new, it doesn’t have this belt—instead, the problem often lies in the condenser fan. A squealing or grinding noise coming from your outdoor unit can be the first signal that the condenser fan’s motor is in need of replacement.

Hissing Sounds

A/cs operate via a closed-loop system, which means that the refrigerant used to cool the air that’s circulated through your home can be reused over and over. But when this closed-loop system develops a leak, refrigerant can escape and make it impossible for your unit to fully cool the air being cycled through.

Technicians can use sophisticated leak-detection equipment to quickly find and repair leaks in your system; however, serious leaks can often allow refrigerant to escape quickly enough that you can hear a slight hissing sound from your indoor or outdoor unit. In these cases, you’ll usually notice that your a/c isn’t cooling the air or is cycling on and off frequently.

Buzzing Sounds

Buzzing sounds can come from several sources, making them more challenging to diagnose. Just a few of the potential causes of a buzzing a/c unit include:

  • Loose parts rattling around somewhere inside the unit
  • Missing or broken isolation feet
  • A malfunctioning compressor
  • A refrigerant leak that has caused the unit to freeze

Figuring out precisely what’s wrong will require you to answer a few questions, like:

  • Does the unit buzz constantly, or only when it’s running?
  • Is the a/c adequately cooling your home?
  • Is there visible evidence of condensation on or around the unit?

Because the issues that can cause a buzzing a/c unit don’t usually lend themselves well to DIY repairs, it’s a good idea to contact an a/c service technician for diagnosis and repair.

A/C Designs can help. Whether your unit needs some TLC or you just want to schedule some preventive maintenance, our experienced technicians can quickly get to the bottom of any issues you’re facing. Give us a call or fill out the short contact form on our website to quickly get in touch with one of our technicians.