Why is My Air Conditioner Squealing?

By July 22, 2019 June 28th, 2024 Air Conditioning

AC Service | Air Conditioner Squealing | St. Louis, Missouri

It’s that time of year when the summertime St. Louis heat and humidity make us all want to retreat into the cool refuge of our air conditioned homes. Perhaps that’s why there are few things as disconcerting as hearing squealing or squeaking noises coming from your AC unit.

If you’re hearing a squealing noise when you turn on your AC or fan, it’s usually caused by one of a couple of possible reasons:

1. Air conditioner is squealing because the fan belt is worn out or misaligned.

In some air conditioners, a belt connects the motor and the fan. As the humidity level rises in our hot, summer Missouri air, the belt can expand and contract. Like the belt in your car or lawnmower, your air conditioning belt can stretch or become fragile over time. If this is the cause, the sound of your air conditioner squealing may come and go as the temperature and level of humidity varies throughout the day.

If this is the problem, you should contact a qualified HVAC repair service.

2. The condenser fan bearings are worn, causing an AC squealing noise.

If you have a newer air conditioning unit, it likely does not have a belt. The condenser fan is attached with bearings that eventually wear out. One of the first and only symptoms of this issue is that your air conditioner emits a loud squealing noise that can be heard when the unit is running. If this is the case, it’s important to address the problem as soon as possible. Left unresolved, worn bearings can damage the air conditioning motor over time, costing you the inconvenience of loss of cold air and more money in the long-run.

In either case, calling on an HVAC repair service you can trust is important. Let Design Aire help.
Reach us at 314-739-1600, seven days a week, 8 a.m. to 9 p.m.

Other Common Air Conditioning Noises:

Hissing or Screeching
If your air conditioning unit is emitting a high-pitched screeching or hissing sound, the most likely cause is high pressure built up in your compressor. If this is the case, the sound will most likely be heard outside at the unit when the AC first kicks on and will last about 10-15 seconds. You may also notice that your AC unit stops and starts more frequently than normal. If you hear this sound, stop running your air conditioning until it can be checked out by a qualified AC repair technician. High pressure can be very dangerous, and your air conditioning should be inspected right away.

Clanging, Knocking, Clicking or Banging
If your AC unit is clanging, knocking, clicking or banging when it runs, but the noise doesn’t happen when your thermostat is set to “fan,” the most likely reason is that there is an obstruction in your fan. It is possible, for example, that a small stick is lodged inside, or that the fan needs to be tightened. See if there is anything obviously sticking out on the outside, but if not, call a professional. Don’t run your AC if you continue to hear these noises, or you can cause further damage. Contact a licensed AC service in St. Louis. 

Gurgling or Bubbling
If your air conditioning unit is emitting a watery gurgling or bubbling noise, the most likely causes are that the condensate drain is making noise, or that you have a refrigerant leak. Check your condensate drain to make sure it has a proper trap. Often, this will resolve the problem. If it’s a refrigerant issue, chances are good that the problem won’t hurt anything if you allow it to continue to run, but you should call a St. Louis AC repair service to check it out. 

Unit Won’t Start and You Hear Clicking
If your unit won’t turn on, but instead, you hear a clicking noise, chances are good that there is an electrical problem such as a compressor or capacitor problem, or perhaps a faulty thermostat. Call a trusted St. Louis HVAC professional to resolve the problem.

Hearing Noises from Your AC?

Design Aire in Maryland Heights services St. Louis, Ballwin, Chesterfield, Kirkwood, Webster Groves, Creve Coeur, O’Fallon, Lake St. Louis, Wildwood and other surrounding communities. We are a BBB Torch Award-winning business and the Midwest’s #1 Trane dealer.


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