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W.C. Butler Heating and Air Conditioning Blog

Noisy AC? Don’t Ignore These Particular Sounds


It would be great if we had air conditioners that could self-diagnose themselves and then send us an alert through an app on our smartphones to tell us that something is amiss. To be honest, that’s probably not too much of a stretch for the future. Unfortunately, it’s not a reality quite yet.

For now, we do have to rely on other means to warn us that something is wrong with our air conditioning systems. Perhaps it’s a sudden drop in cooling power, or an unexpected rise in your energy bills. Or it might even be that your circuit breakers connected to your AC system are constantly tripping.

One of the most common signs that something is wrong with your air conditioner is that it’s making loud or unfamiliar noises. You know more than anyone the everyday sound of your HVAC systems. If something sounds strange, it’s worth giving our team a call.

So what kind of sound are we talking about? Read on!

Mechanical Shrieking

Have you noticed a pretty loud mechanical shrieking noise coming from your air conditioner? This is most likely the sign of a motor problem, or at the least it’s a sign of a motor bearing’s lubrication wearing out. This isn’t a huge problem! Actually, it’s a natural part of wear and tear.

However, it doesn’t mean you should ignore the sound. When left unaddressed, “natural” wear and tear can lead to a very unnatural emergency breakdown. Give us a call so that we can re-lubricate or check any other motor problems you’re having, before the motor overheats and really does lead to an AC breakdown.


A grinding noise is another sound that is usually indicative of a motor problems. It’s usually caused by a motor that has too much debris on it—like dust. Or it could be the start of the lubrication wearing down, like we mentioned above.

It’s very important to pay attention to smells here too. If the grinding is accompanied with an acrid odor wafting through the vents, then it’s a sign that your motor has already started overheating. If this is the case, please shut off your air conditioner right away and give our team a call.


In the best-case scenarios, a rattling noise is extremely minor. It might be the sign of nothing more than a loose cabinet door—something you could potentially fix on your own with a few twists of a screwdriver.

Another thing it might be is that loose components are being knocked around in your blower fan, or you have bent fan blades that are banging around. Rattling isn’t a sound you should ignore, so if you can’t find the culprit easily, give us a call.

Hissing or Bubbling

If you hear a sound that resembles hissing or bubbling, then you might be hearing refrigerant escape your system. Your air conditioning system is supplied with enough refrigerant during manufacturing to last its entire lifespan. So, if your system is losing refrigerant, it means there is a leak. The leak must be located and professionally repaired. If this doesn’t happen, then it can eventually cause damage to the compressor… and once the system’s compressor breaks down, you may need to replace your entire air conditioner.

W.C. Butler Heating and Air Conditioning is your trusted resource for quality AC repair in Roanoke, VA. Contact us today!

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