When your house or office is too hot or cold, you turn to your AC for a comfortable environment. Even so, your AC sometimes makes lots of bothersome noises when activated. Many of these noises signify underlying problems, and the louder they are, the bigger the issue. Watch out for the noises below to tell when you need to troubleshoot or contact professional AC repair services.

1. Bangs, Clangs, and Clanks

The noises mentioned above result from failed motor bearing, bent blades, failed compressor motor, or detached parts. Detached parts hit the frame to cause bangs and may not be a big problem but can cause significant damage. For instance, they may cut electrical wires and cause a fire outbreak or damage the unit's interior. Don't ignore any loose or detached parts as they reduce the efficiency of your AC.

2. Squeaks or Squeals

Blower motor or fan motor problems cause squeals and transmit the noises through the air ducts. Note that sometimes the AC squeals upon startup, and that is normal. Nevertheless, you likely need inspection or AC repair if the noises weren't there previously.

3. Vibrations and Buzzes

Buzzes could result from debris, electrical issues, worn-out air filters, dirty condenser oil, or unbalanced fan blades. A more severe issue that may cause your unit to buzz is a refrigerant leak. So, it is best not to ignore buzzes since you can't be sure whether the issue is minor or extreme.

4. Rattles

Rattles signify various problems ranging from minor cases like a loose cabinet door to more serious concerns like loose components. You can resolve a loose cabinet door or your own unless the damage is at the foundation. However, bent fan blades or worn-out fan belts require expert services. Rattles can also indicate that your unit has aged.

5. Screams 

The most serious noise your air conditioner can make is screams or high-pitched whistles. Common causes of screams are high internal pressure and freon leaks, which are dangerous ordeals. If you hear screams, you need to immediately switch off the AC unit and call an expert. Note that some AC units come with sensors that automatically shut down the unit when there is over-pressurization.


You can prevent many AC problems and noises with regular maintenance. Always keep an ear open and watch out for the normal AC operations. Don't wait until the problem escalates if you notice any intrusive noises. Instead, contact a professional to inspect the system, perform repairs or replacements, and schedule regular inspections.

For more information about AC repair, contact a local HVAC professional.