Sound Check: 5 Sounds That Indicate A/C Issues

You have a good idea of how your air conditioner sounds under normal operation, which makes strange noises stand out from the usual din. Strange noises are often a warning that something within your air conditioner is amiss and needs attention as soon as possible. If you hear any of the following sounds, then it's time to have your unit inspected.

1. Metallic Grinding

If you hear the sound of metal grinding against metal, chances are it's a moving part that's in trouble. The most common component to suffer this fate is the blower fan motor. The bearings inside the blower fan motor can fail over time, leading to increased friction and grinding noises. If the problem isn't addressed quickly enough, the motor itself may fail and require replacement.

2. Hissing

If you hear hissing sounds from your air conditioner, it's likely due to a pinhole leak in one of the refrigerant lines. The sound of high-pressure refrigerant escaping through a small leak often mimics the sound of a tire leak. Refrigerant leaks should be addressed as soon as possible, since low refrigerant levels can also reduce your air conditioner's overall performance.

3. Squealing

In most cases, intermittent squealing can be traced back to a worn-out or misaligned fan belt. Squealing sounds caused by bad belts can come and go, as the belt contracts and expands, due to heat and humidity. Replacing the fan usually solves this problem.

Squealing sounds can also be caused by moving parts that are in dire need of lubrication. An experienced professional can inspect and lubricate bearings and other moving components.

4. Constant Clicking

If you hear a constant clicking noise while your air conditioner runs, the culprit could be as simple as an object stuck in the path of the blower fan. With the system turned off, make sure there aren't any objects or debris blocking the fan. If the noise persists, have a professional check the air conditioner's capacitors and relays for any signs of malfunction.

If you can't turn on your air conditioner and get constant clicking instead, you may have an electrical issue on your hands. Have a professional conduct a complete inspection of your air conditioner to pinpoint the problem.

5. Humming

Humming noises could mean any of the following:

  • There's a loose component that's causing vibration while your air conditioner is running.
  • Loose or damaged wiring is preventing an air conditioner component from starting properly.
  • The compressor is malfunctioning and due to fail soon.

Any of these issues can spell trouble for your air conditioner. Upon hearing any humming noises, have your air conditioner inspected by a trusted air conditioning repair professional.