Listening to the Health of Your A/C Unit

Sometimes the best way to diagnose the condition of your air conditioning unit is by using your ears. Just like a physician listens to what’s going on inside your body with a stethoscope, many times a rattling or murmuring can clue a repairman in on a malfunctioning component and how to fix it.

Although making the proper repairs will often require the experience of a qualified professional, you can (and should) familiarize yourself with the normal sounds your A/C unit makes, and the noises that are unusual, so that you can recognize when it’s time to call a repairman before further damage is done.

Here are a few warning signs of trouble to listen for in your unit:

Bubbling, Gurgling, or Hissing

More often than not, bubbling, gurgling, or hissing sounds are caused by a refrigerant leak somewhere in the compressor. A leaking compressor means your air conditioning isn’t getting as cold as it should, and less refrigerant not only makes you overwork the unit to cool a room (which leads to a higher energy bill), but also is toxic to the environment. If you hear any of these noises, call an A/C repairman to take a look immediately.

Clanking, Rattling, or other “Metallic” Sounds

Fixing a clanking, rattling, or metallic sound could be as easy as tightening a bolt or replacing a piece of hardware. Whatever the case, these sounds usually originate from the mechanical parts of the unit, such as the fan. Generally, metallic sounds are the cheapest and easiest problems to solve – however, it can result in more serious problems in the future if gone unchecked.


Buzzing sounds indicate that there is a problem with an electrical component of your unit. Electrical shorts in the compressor can create a buzzing or popping, which, if left unattended, can be a serious fire danger. If you hear one of these sounds, get it inspected straight away.


If your A/C unit is not functioning properly, and you hear a rapid and repeating clicking sound, then you may have a faulty relay or control unit in the compressor. Your system will not work correctly until it is fixed.


One of the most common and loud sounds faulty air conditioning systems can make is a wailing noise, caused by your system running at full power. In addition to creating noise-pollution, wailing typically means something is wrong with your unit’s fan belt. It may simply be dislodged or require lubricant.

If your air conditioner is making one of these sounds, or any other unusual noises, we urge you to contact a metro-Atlanta A/C technician to take a look. It may be a cheap and simple fix, but if left undiagnosed, there can be more costly damage down the road.