What Are the Most Common Air Conditioner Noises?

Air conditioners can contain a symphony of noises. Each one can tell you a lot of what problems your air conditioner is having. It could be something easy, like chirping, or a high-pitched shrieking!

You need to know what these sounds mean and how to describe them to the technician. These noises are not for the faint of heart! So read on to learn what the most common air conditioner noises mean!

Whistling or Hissing

A persistent whistling or hissing noise could be a sign of a refrigerant leak. The source could be a leaky valve or in the refrigerant line itself. At the first hints of whistling or hissing, call your local air conditioning repair shop to get it looked at.

Keeping the unit off until you get the unit looked at is very important as the most common refrigerant is Freon gas and breathing the gas could be very dangerous. The hissing could become a high-pitched shriek. If you hear that, immediately turn the unit off and call your technician.


Buzzing could indicate an electrical problem in a few air conditioning components. It could be the condenser fan motor, the circuit breakers, or the contactor relay switch, among other things. The buzz you hear is electricity jumping between the circuitry and happens when air conditioner units get older.

It’s important to get this fixed, as this could potentially start a fire. Electrical fires are one of the leading causes of wildfires in the Western United States. When you hear the buzzing, especially with an outdoor unit, turn it off and call your technician immediately.

Metallic Grinding Noises

It’s never a good sign when you hear a metal-on-metal grinding sound, and in the case of an air conditioning unit, it can be a serious problem. The noise means either a compressor problem or a bad belt. With compressors, the grinding noise comes from the pistons, which compress the refrigerant, start to wear out.


If you hear some banging coming from your air conditioning unit, it could indicate that something inside is loose. It could be anything, a connecting rod, a piston pin, or a crankshaft making extra noise. Make sure to contact your technician to get things tightened up!


If any extra noises starting coming from your unit, chirping is the one you want. It’s likely an indicator of friction between parts. Examples include the fan rubbing against the blower cage, a worn-out fan belt, or dry motor bearings.

Any of these can be easily corrected by your technician, but are not truly urgent. If the noise sticks around for a long time or develops into a shrieking noise, then it might be a series issue. Call your technician right away!

Air Conditioner Noises

Your air conditioning units can make a lot of noise. Each one of the air conditioner noises indicates specific problems, so make sure to keep your ears out! And if you live in and around Jasper, Texas, make sure to call A-1 Refrigeration and Air Conditioning!