HVAC Noises and What They Mean

The ideal HVAC systems operate so silently enough that you just might forget they’re there. They tend to get louder, however, with constant use through the years or simply because of age. Thankfully, the noises they emit are merely signs of impending issues. Give them immediate attention and you can avoid costly problems, but ignore them for too long and you may find yourself in need of AC repair services sooner rather than later.


Pay close attention to signs your AC might be in need of repairs. You’ll get the most mileage out of your investment and you’ll be more comfortable indoors for much longer. This is why in today’s post, we’ll discuss various types of HVAC noises that tell you if something’s wrong with your system.

AC Rattles

Constant rattling noises can be a sign that your AC needs repair. Depending on the severity of the rattling, it could mean a few things. Should you have an outdoor unit, the likely cause of the rattling is some kind of external debris, like a stuck twig. The fact is that even if grates protect your system from small refuse, other, finer objects could still sometimes get through. You can stop the rattling by simply turning your system off and removing the litter, but if you discover visible signs of damage to your unit’s components, such as the compressor, condenser coils, or the fan, you’ll need to call an HVAC technician at once.

A Hissing Air Conditioner

When you hear your HVAC system hissing, the most likely cause is escaping air. Pay attention to your walls as hissing coming from inside them may be a sign that your ducts are compromised and leaking. Take note that not all hissing sounds are emergencies. If the hissing is light, the likeliest source could be your air vents. In such cases, you can change the air filter to a more appropriate size, which would create a better seal and eliminate the hissing sound.

Clanking Noises From Your HVAC Unit

Clanking noises are a red flag. Something’s definitely wrong with your air conditioner, which could mean anything—from damaged parts and detached components to loose pieces that may be inadvertently rubbing against each other. Worse, they may interfere with each other’s operation, causing unit failure. Of all the types of noises discussed, clanking is the most serious one and it requires immediate attention from a qualified HVAC technician. Turn your system off and not use it until you’ve had repairs.

Different sounds coming from your AC unit could mean different things. With a little research, effort, and help from a premier HVAC contractor, you can stop AC unit problems dead in their tracks.

And of those leading HVAC contractors, Bartlett Heating and Air Conditioning is the heating and cooling specialist you can turn to for all your HVAC system concerns. You can count on us to get to the bottom of things and make your air conditioning unit quieter and much more efficient.

We are here for you! Call us today at (630) 504-7855.