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50+ Years of Serving
The Shreveport Area

50+ Years of Serving The Shreveport Area


Moon's Air Blog

What Does That Noise From the AC Mean?


You already know the standard sounds your home’s air conditioning system makes when it’s running: the whir of the fans, the hum of the compressor, an occasional click at start-up, the movement of air through the ducts. You probably don’t think much about these sounds—they just become part of the white-noise of the middle of the year. 

Then … something different happens. A new sound appears. And you’re not happy about it. Does it mean something is wrong with the AC?

It’s possible. Odd or loud sounds from an air conditioner are common warnings that there’s a malfunction that needs the attention of pros. Below we’ve listed some of the more common AC warning noises as well as what they may mean. When in doubt, call our professionals for air conditioning repair in Shreveport, LA.


A few clicking sounds at start-up is normal for an AC. But when the clicking sounds start to become incessant, it’s often warning of an electrical fault in the system. One source of this noise is failing capacitors, which are the parts responsible for sending voltage to the motors. Heat exposure can cause capacitors to lose their ability to hold an electric charge, and this clicking sounds indicates one that’s close to dying. You’ll need professionals to replace any capacitors.


This might be as simple as a loose latch on the HVAC cabinet door. But it also could indicate that a part has come loose somewhere in the system and is clattering around. This isn’t something to ignore, since the loose part may be important, and you don’t want it banging around causing damage to other components.


This is a sound like high-pressure air escaping from a leak—and that’s very close to what it probably is. Hissing from an AC is usually the noise of a leak in a refrigerant line that’s allowing the refrigerant charge to escape. Loss of refrigerant will not only put your home’s cooling in jeopardy, but also the air conditioning system as well. If the leaks aren’t sealed and the proper amount of refrigerant restored, the compressor will burn out. 


A sharp, metallic clang sound can be startling coming from the AC. This could be due to a number of loose parts, but the most likely source is a bent fan blade or misaligned fan in either the indoor air handler or the outdoor condenser. This can do immense damage to the air conditioner, so we recommend you shut off the AC and call for professionals to fix the problem. 


This is another electrical warning noise, and it usually means there’s a loose electrical connection or a faulty relay switch that is causing arcing. Shut off the power to the AC and then call for technicians to fix it. You do not want to fiddle around with an electrical issue with the air conditioner. 


A high-pitched mechanical screeching sound is warning you that the bearings in one of the motors are wearing down. You’ll want professionals to replace the bearings before they wear down completely and put the motor in danger of burning out. 

Moon’s Air has provided whole-house comfort since 1971. Call us today—It’s good to be Mooned!

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