Ideally, your air conditioner is relatively silent. However, sometimes the unit makes unusual noises that require investigation. You can keep your AC in good condition by having it serviced every spring and changing its air filter on time. Pay attention to these 5 abnormal air conditioner noises and learn what they mean.

Banging Air Conditioner Noises

A banging noise coming from your air conditioner means that a part is broken or loose inside the compressor. Perhaps the compressor needs to be completely replaced. It could also signify an imbalance of the indoor blower.


Buzzing noises coming from the HVAC system can indicate a variety of problems, for instance:

  • Debris in the unit
  • Loose fan motor or blades
  • Dirty condenser coil
  • Clogged air filter
  • Bad blower
  • Copper lines rubbing against something
  • Refrigerant leaks

The last option is likely the culprit if the AC is running but the temperature inside isn’t going down.


Humming isn’t the worst sound to hear coming from the AC, but it should still be investigated. It could point to an electrical issue or a loose part causing vibration.


Clanking air conditioner noises are hard to ignore and they shouldn’t be brushed off. The compressor may be loose and require replacement. The blower fan blades could be out of balance and running into other components, possibly damaging them. Because parts are clanking together, the problem can cause damage to spread.

Whirring Air Conditioner Noises

A whirring noise that sounds like a helicopter is usually the result of a broken belt or issue with the fan either in the indoor or outdoor unit. It could also be a more minor scenario like a piece of paper or leaf stuck inside the fan.

You are less likely to experience any of these warning signs if you maintain your HVAC system consistently. Besides paying attention to strange noises, keep the exterior unit clean, schedule regular inspections with a technician, and always change the air filter on time. Putting in a small bit of effort will prevent problems and breakdowns of your air conditioning unit. Keep a calendar of maintenance tasks so that they don’t slip by you.

Home Inspectors of Middle Tennessee provides home inspection services in and around Nashville. Contact us to schedule an appointment.