April 6, 2021
Air Conditioner

Listen, did you hear that noise coming from your air conditioner? If so, it may be trying to tell you something is not working properly. By tracking down the noise, you can get an idea of what may be wrong, and start guessing at the repair costs.

Do not worry if you are not an air conditioning expert. A simple review of this list will put you ahead of most people and help you know when you need to service your system.


The average air conditioning system will last 10 to 15 years when it is properly maintained. Some of the clues that it is aging and nearing the end of its service life are various rattling sounds from many places within the system.

The first thing to check is your condensing unit outside. Make sure there aren’t any twigs hanging down and hitting the fan as it spins.

If there is a chattering sound coming from the outside unit, it may be your contact opening and closing quickly. This is a simple fix, but left unattended can damage your compressor.

Clanking or Banging

Clanking or banging sounds are an indicator something has come loose or broken. This could be as simple as the blades on the condensing fan have come loose. It may also indicate a broken part like a crankshaft or connecting rod inside your compressor.

Inside your home, it could indicate that your circulating fan is out of balance. Anything left out of balance or loose will end up causing bigger damage to your system, costing more in repairs.


Buzzing is never a good sound to hear coming from your system. This can be caused by loose parts or debris caught in the inside or outside unit.

It could also indicate loose or unbalanced fan blades. Along those lines, it could indicate a fan motor that is malfunctioning.

It may also indicate your condenser coil needs to be cleaned. This should be part of your annual preventative maintenance routine. While at it, be sure to check your air filters, which could also cause a buzzing sound.


You may expect to hear a screaming sound from a toddler, but not your air conditioning system. If you do hear a screaming, shut your system down immediately. The most common cause for this is a refrigerant leak.

Any leak can cause damage to your compressor if not resolved. If the leak is inside your home, this could pose a hazard to the health of everyone inside. Call a professional for repairs before continuing to run the system.


Your system should do some clicking as it cycles on and off. This is caused by the relays on the control boards activating to start various parts of the system.

However, if that clicking is constant, or continues as your system runs, it indicates a problem within the system. This should be diagnosed by a trained technician to ensure the right parts are being replaced.


Like screaming, squealing will likely draw your attention very quickly. The most common mechanical cause of squealing is a problem with the bearings in one of the fan motors. If they are failing or needing lubrication, they will give off a squealing sound.

For some units, it may be normal to hear a little squeal as the system starts up. However, if you question whether it is normal for your system, have a professional diagnose it to ensure your system is working properly.


Humming noises can point to anything from minor issues to major problems. On the minor side, it may indicate a loose part in the system. However, if it is loud and coming from your outdoor condenser unit, it may indicate a bad capacitor. The capacitor stores a large charge of energy to kick on the compressor and condensing fan motor. Without this critical component working properly, both will fail to cycle on.


Whirring is always an interesting sound to troubleshoot. This can be caused by an innocuous piece of paper caught somewhere in the system. However, it may also indicate more serious problems like bad bearings or loose fan blades.

Prevent substantial damage to your system by attending to possible problems early. BEST Air Conditioning Plumbing Repair has been a trusted name in air conditioning repair around Las Vegas since 2019. We also offer maintenance plans and new system installation, along with a full range of heating and plumbing services. Do not wait any longer. Call us today to schedule your AC repair.

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