HomeBLOGAir ConditionersWhy Is My Air Conditioner Making a High-Pitched Squeal?

Why Is My Air Conditioner Making a High-Pitched Squeal?

When you’re about to call it a day, your air conditioner starts making strange noises, driving you crazy! Making matters worse, you have no idea how to make it stop. And if that isn’t bad enough, the sound it makes seems to get louder by the minute. Talk about a good night’s sleep possibly turning into an all-nighter!

One of the most annoying noises an air AC can make is the squealing type. Though some air conditioners normally squeal during the first few minutes of running, a loud and persistent squealing noise signifies that something might be wrong. Either way, squealing AC noises should not be taken lightly, and the sooner you do something about it, the quicker you’ll fix the problem.

Continue reading to find out what might be the reason for your AC squealing and what you can do to silence it.

Why Is My Air Conditioner Making a Squealing Sound?

A squeal is a long, high-pitched sound produced by your AC while it’s turned ON. While this noise may be tolerable at first, hearing it constantly can disrupt the peace and quiet in your house, especially at night.

Below are a few possible causes for a squealing air conditioner: 

Low Return Airflow

Your air conditioner’s condenser and evaporator coils function by collecting the dirt that the air filters aren’t able to. Eventually, these coils become dirty – resulting in low return airflow. Compromised coils also become insulated, and their ability to properly absorb heat is affected.

While accumulated dirt is a common and relatively minor issue, other possible reasons for a squealing AC could be more serious.

Duct Leaks

The ducts are another essential part of your air conditioning system. Their primary function is to make sure air is transported and properly circulated all around your house. But when your ducts are leaking, the airflow becomes compromised, making your AC produce a high-pitched squealing sound.

Duct leaks can also lead to warm spots due to poor air circulation and dusty areas within your room. Additionally, duct leaks make your AC expend more energy, resulting in higher electricity bills.

Bearings and Belts

If you own an older air conditioner, a belt usually connects the fan to the motor. The belt stretches as the air humidity outside rises. Once your AC starts to make a squealing noise, it’s a sign that the belt is starting to become worn out.

Instead of a belt, newer air conditioners have bearings attached to the condenser fan. When this part wears out, you will hear a loud squealing sound that won’t stop unless you turn OFF your AC. Worn-out bearings can also damage your motor if you don’t do anything.

Dirty Air Filters

The air filters are responsible for maintaining your AC’s overall efficiency. When these filters are dirty or clogged, airflow reduction significantly affects your AC’s performance. Dirt and any obstructions on the air filters result in poor airflow on your AC  – thus producing a squealing noise while it’s running. 

How do you fix a squealing air conditioner?

How do you fix a squealing air conditioner?

We’ve already discussed some of the reasons why air conditioners make a high-pitched squeal. Fortunately, there are a few things you can do to make the noise stop:

  • Examine your ducts and see if there’s any sign of leaking. If you find leaks, use a mastic sealer to cover them up (the smaller ones are easier to seal). Unfortunately, leaks often happen in areas of the duct that are hard to reach and can only be fixed by a professional. This video should tell you more.
  • Sometimes, all your AC needs to make it function better is a little cleaning. You should always find time to clean your air filters and coils. This prevents dirt and other particles from clogging up the filters and overloading the coils – thus maintaining good air quality.
  • Check the condition of the bearings or belt. If they look worn out, it would be best to have them replaced as fixing these only provides a temporary solution. This also applies to other faulty parts of your air conditioner. Watch this video to learn how bearings are replaced.

Additionally, it would also help to listen to other noises apart from squealing. Different types of AC noises may indicate other potential problems. Detecting these issues early is the key to fixing them immediately.


About Everyone will agree that there’s no air conditioner sound more annoying than high-pitched squeals. Once you’ve determined its cause and done what’s necessary to make it stop, the next step would be to make sure that your AC is in the best possible condition.

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