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Serving Chester County & Surrounding Areas


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Signature HVAC Blog

What’s That Noise From the AC Mean?

One day, we will have advanced air conditioners with complex AI technology that allows them to rapidly diagnose any malfunction (or even predict it) and notify homeowners they need to call for technicians. They’ll probably be able to automatically contact the technicians themselves. Since we’re not at that level of air conditioning technology (yet), we need to rely on interpreting other warning signs that an AC is on the fritz. One of the most common warnings are strange noises.

What Are “Normal” Air Conditioning Noises?

Good question. To understand warning sounds from an air conditioner, you want to know what you should be hearing. Air conditioners are designed today to run quieter than ever before, but they still make noticeable sounds. The basic noises you can expect to hear during operation:

  • Clicking at startup
  • The motors powering the blower fan and the outside exhaust fan
  • The motor powering the compressor
  • Air moving through ducts
  • Dripping water

Other sounds usually mean something is wrong. If your air conditioner is making the same noises as usual, but making them louder, then it may also be a reason to call for air conditioning repair in West Chester, PA.

What Do the Odd Sounds Mean?

Although you should leave the diagnosis of what’s wrong with your air conditioner to your HVAC technician, we can give you an idea of what to expect from the different strange sounds.

  • Mechanical grinding/shrieking: This indicates problems with one or more of the motors. Shrieking is the sound of the bearings in a motor wearing down; when they wear down entirely, the motor will be in danger of burning out. Repairs to replace the bearings can rescue the motor. Grinding often means the motor is burning out. Shut off the air conditioner and call us.
  • Hissing: This sound is like high-pressure gas escaping from a pipe—because that’s probably exactly what it is. You’re listening to the noise of refrigerant escaping through a leak in a copper line. Refrigerant leaks put the entire AC in danger of failure, so have this looked into ASAP.
  • Rattling: When you first hear this, check to make sure the door on the cabinet is latched; it might be that simple. It could also be a loose piece rattling around in the fan casing or elsewhere, and this can cause significant damage. If the rattling sound is coming from the outside cabinet, and the cabinet is vibrating, the compressor may be in danger.
  • Clicking: We noted above that clicking is a normal sound at startup. But you shouldn’t hear it often. When it becomes something common, it indicates there may be a problem with the compressor’s electrical components.
  • Clanging: A sharp metal clanging or banging noise usually means a bent or loose fan striking the outer housing. This is something else you want stopped right away.

You can put your trust in our NATE-certified professionals to find out what’s wrong with your cooling system and then have it fixed.

Look to the Signature Service You Can Trust: Signature HVAC provides quality air conditioning repair and more to Chester County and the surrounding areas.

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