Sound Guide: HVAC Noises & What They Mean

The last thing you want is for your heating and air conditioning to shake, rattle, and roll. But sometimes, you might hear some unexpected noises coming from your HVAC equipment, especially if your system is older or not well maintained. Before you panic, take a look at this quick guide to what they mean.

Squealing and Screeching

No one wants to hear squealing and screeching, especially in their own house. If these noises come from your HVAC unit, it could indicate a bad fan belt, a failing motor, or motor bearing issues.

Banging and Thumping

Some ducts can make a banging sound when the temperature changes as air blows through them and they expand and contract. Banging and thumping can also come from loose components or broken parts inside the equipment.

Vibrations and Rattling

If there are loose parts within the components of your HVAC system, you might hear vibrating and rattling.


If your compressor fails, it could start making a grinding sound. The pistons usually cause this within the compressor.

Clicking and Clacking

If you hear clicking or clacking as your heat or AC turns on or off, it could be an electrical issue. It’s also possible the clicking is an issue within the thermostat.

If you hear any new or unusual sounds coming from your heating and cooling system, don’t ignore them and hope they go away. Any loud noises could be cause for concern. But don’t panic, just contact the experts at your local McCall’s dealer today to schedule a service call.