air conditioner making noise

Is Your Air Conditioner Making Noise?

Is Your Air Conditioner Making Noise?

Typically, your air conditioner should last anywhere from 10 to 15 years. However, breakdowns can occur unexpectedly—especially if you don’t keep up with the maintenance of your unit. However, right before your unit is about to fail, it will give you some signs. One of these might be your air conditioner making noise.

While it’s common for your AC to make some sounds, there are noises that should be cause for concern. Read on to discover what you need to know about certain sounds coming from your air conditioner.

Common Air Conditioner Making Noise Sounds

There are several different sounds your air conditioner making noise can sound like when it needs attention. So if you hear any of these while your air conditioner is running, it’s advised that you turn your system off and call an HVAC service provider.

It's important to note that if your air conditioner is making noise and you continue to let it run, you could cause serious damage. You may be a bit uncomfortable until the technician arrives, but this could wind up saving you more money in repairs.


changing hvac filter

Should you happen to hear a buzzing noise coming from the condenser, this could be an indication that there’s something wrong with the electrical system.

You’ll more than likely hear this sound while the system is running and when it’s not. There are several different issues that could be causing the buzzing. These include the following:

  • The electrical connections between the parts are old or coming loose.
  • The contactor relay switch might be faulty.
  • The condenser fan isn’t turning when the insider blower is.

To keep your house cool and comfortable, you need to take care of these issues as soon as possible.

Hearing a buzzing noise coming from your air conditioner could also be an indication that you need to change your filter. This is something that’s quick and easy to do and doesn’t require a technician. If you complete this task and your AC continues to buzz, then this wasn’t the problem. Calling a technician is in your best interest.


Another indicator that there might be something wrong with the electrical system of your air conditioner is to hear a clicking.

You should hear a click when the AC first turns on and when it shuts off. This is completely normal.

However, if you hear a constant click, this could be an indicator that your thermostat is failing or you have a defective control.

With so many electrical components making up your AC unit, getting these taken care of as soon as possible ensures that your system will continue to keep you cool.


Neglecting to maintain your AC could result in an air conditioner making noise. If you happen to hear hissing coming from the unit, this could be a sign that you are leaking refrigerant.

This is often caused by coils that aren’t cleaned on a regular basis. They will become corroded and small cracks and holes will form, which will allow the refrigerant to escape. You need this item to cool the air before it gets into your home, so it should stay inside your AC unit.

Some of the other things you might notice in addition to the hissing sound is air in your home that isn’t as cool as it should be. Your air conditioner will also be running more often than usual. Having professionals take care of this issue will ensure that cool air can continue to circulate throughout your home.

In addition to a hissing sound, your air conditioner might also scream if the refrigerant is leaking.

Not only will this sound be awful to listen to, but leaking refrigerant can also cause health issues. Thus, whether your system is making a hissing or screaming sound, getting this checked out as soon as possible is advised.


Strange Air Conditioning Sounds Inline

Probably one of the most concerning noises that your air conditioner will make is a loud banging. It will also be hard to ignore.

This could be an indication that there is a broken or loose part in your unit. This could be a connection rod, crankshaft, or piston pin—all of which are located inside the compressor.

It might also be a sign that your entire compressor needs to be replaced or that the indoor blower is unbalanced. Having a professional check out your system is the best option when it comes to quickly pinpoint the problem. They’ll also be able to get the issue fixed so that your air conditioner will run as quietly as possible.


If your heater and AC make a loud noise, especially a high-pitched squealing sound, this could be an indication that there are problems with your fan or blower motors. Generally, these are signs that they are about to fail.

If the squealing sounds like it’s coming from outside, this could mean that you have a bad compressor or a faulty fan motor.

Should the sound be coming from inside your home, then it is coming from the blower fan. This component is responsible for pulling in warm air so that it can be cooled. If this isn’t working properly, in addition to the squealing, you might also notice that your house isn’t as cool as it can or should be.

In addition to the squealing, you might also hear the sound of metal grinding on metal. This is an AC fan noise that could lead to serious problems if you ignore it. Getting this taken care of as soon as possible will prevent further damage from occurring to your AC.

Whining or Whistling

Should you hear whining or whistling while your air conditioner is running, this could be a sign that you have an issue with your ducts.

These are the tubes that run throughout your entire house and deliver the cold air from the central unit to every room in your home. If there are holes, cracks, or faulty connections, then the cold air won’t be able to reach its destination.

Not only does this mean that your house won’t be as cool as you prefer, but it could also mean that your air conditioner has to keep running to maintain the desired temperature. This will increase your utility bill.

Whining or whistling could also be an indicator that your air filter is dirty. If air can’t flow freely through the unit, this—again—might mean that your system has to work harder to keep the house cool. Again, this could mean that you are paying more than necessary to run your air conditioner.

As mentioned, you can change out your own air filter. However, if you do this and find that it doesn’t eliminate the whining or whistling noise, then you’ll need a professional to help you find the exact cause of the sound.

Constant Running Noise

In addition to having a noisy air conditioner, you may hear sounds like the unit is constantly running. This may be quieter, but it’s still a sound that should make you concerned.

This issue might be caused by bent coil fins or coil fins that are covered in dirt and grime. Either of these issues will mean that your AC is struggling to cool the air to the desired temperature. If it runs constantly, this will wear out and damage parts, which can lead to a complete breakdown.

Since it can be incredibly expensive to replace your entire AC unit, if you hear this sound, call out a professional as soon as possible. The call may wind up saving you a lot of money.


A rattling sound coming from your air conditioner could indicate a couple of different issues. It could be a sign that you have twigs, leaves, or other debris inside your system that are causing a clog.

It could also mean that your system is getting old and parts are starting to come loose.

In either case, it’s beneficial to call in a professional and have them check out the system. They’ll be able to easily find the problem and take care of it so that your AC works effectively and efficiently to keep you cool and comfortable.

How Often Should You Have Your AC Serviced?

While it’s possible that these sounds can occur unexpectedly, you can reduce their occurrence by having your air conditioner properly maintained and serviced.

Ideally, you should have your furnace checked in the fall and your AC checked in the spring. The system should be cleaned and inspected for any issues. By having this service done before you turn your heater or air conditioner on, you should be able to find and correct any issues before they become serious problems.

We recommend you consider an annual HVAC maintenance plan as it can save you money and keep your HVAC system lasting much longer.

What to Do With an Air Conditioner Making Noise

Customer Service Operator

Finding the right heating and cooling technician doesn’t have to be hard. At Crystal  Heating & Cooling, we have the skills and ability to take care of a wide range of air conditioner issues.

No matter what sound your system is making, we’ll be able to locate the problem and find a way to fix it. We’ll get your system back to keeping you cool and comfortable in no time.

Schedule your service today for an air conditioner making noise or for any other cooling need you might have.

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