Understanding The Sounds Your HVAC System is Making

Your HVAC system probably works as it should each day. However, there may come a time when you experience an issue with your HVAC system. One issue that may arise is strange noises emitted from your heating and cooling system. The sounds may cause concern and could mean a problem. Whether the problem is small or large, take these sounds as a warning sign that you should reach out to an HVAC professional for help.

HVAC System Sounds

Here are some HVAC system sounds and what they may mean:

  • Squealing and Screeching: If you hear squealing and screeching sounds coming from your HVAC system, this may signal a bad belt somewhere within the system.
  • Thwapping: A thwapping sound may mean something is stuck in the blades.
  • Clanking, Banging, or Rattling: Clanking, banging, and rattling sounds could be a sign that there’s something in the HVAC system that has come loose and might be rattling around in the system.
  • Popping: If you hear popping, it may be sounds of the cold ducts expanding due to the warm air.
  • Buzzing: A buzzing sound coming from your HVAC system may mean a compressor malfunction, refrigerant leak, or loose part somewhere.
  • Clicking: A clicking sound could signal a problem with the compressor or a handler malfunction.
  • High-Pitched Whistling/Screaming: If you hear a high-pitched whistling or screaming noise, this is a warning sound. Turn off the HVAC system immediately as it could mean high refrigerant pressure.
  • Hissing: A hissing sound often signifies an internal refrigerant leak.

Any of these previously mentioned sounds mean an issue exists with your HVAC system and you’ll want to have an HVAC professional evaluate the problem and handle the repairs.


Your boiler may also make strange sounds and these noises will often point to a problem. Some of the sounds you might hear coming from your boiler include the following:

  • Kettling: A kettling sound often means the water boiler is too high.
  • Gurgling: Any gurgling noises that your boiler emits may point towards air trapped in the boiler.
  • Whistling: Whistling sounds could signal a partial blockage in the pipes.


If you hear any of the above noises, you’ll want to pursue a solution to get your HVAC system fixed and up and running in an optimal state once again. Call an HVAC professional to schedule maintenance on your heating and cooling system. In the meantime, turn your system off until an HVAC professional can come out to evaluate the problem and complete repairs. If you smell natural gas, make sure everyone leaves the house immediately and call 911.

Take the necessary steps to fix any HVAC problems immediately. Contact Air Design for help!

Contact Air Design for all of your HVAC maintenance and repair needs!