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My Air Conditioner Is Making a Pulsating Noise

a white kitchen where you can hear the air conditioner unit making a pulsating noise

When you turn on your AC unit, you expect to hear a soft hum that lets you know your house will cool down in no time. So, when you turn on your unit and hear an odd pulsating sound, you naturally become worried. What is going on?

If your air conditioner is making a rhythmic or pulsating sound, there could be a number of issues going on. The complexity of these issues ranges from a quick fix to a much more complicated problem. While you can investigate on your own, the best way to deal with this kind of issue is to reach out to a professional.

Figuring out why your unit is making noises will involve removing panels to examine the problem further. This can be a complicated process and can lead to even larger issues if you don’t have the training or tools needed for the job. However, if you hire an expert, they can take care of everything for you. And, better yet, help keep you and your family cool throughout the hottest months of the year.

When a professional comes to your home, they will check several different parts of your system, depending on whether you’re hearing a pulsating noise indoors or outdoors. Some common problems that can cause this noise are issues with the compressor or a loose part like a wobbly fan blade.

For indoor components, some of the most common causes of a vibrating noise are problems with the motor blower, blower wheel or filter.

Bearings Are Going Out on the Motor Blower

The motor blower is the component inside the air handler that pulls air through the system, helps power the blower wheel and helps blow cool air into your home.

The Blower Wheel or Fan Blades Are Out of Balance, Damaged or Dirty

This is a circular-shaped part with fan blades that is attached to the motor blower and helps circulate air. Dirty blower wheels are particularly a problem in older systems because dust can build up on the blades. This makes it more difficult for the motor blower to turn the wheel. Additionally, if any of the blades on the fan are broken, warped or bent, this can cause the unit to make a weird noise.

Your Air Conditioning Filter Is Dirty

When the filter is dirty, the motor has to work extra hard to keep airflow going, which might cause a noise. If a dirty filter is causing the sound, then changing out the filters should fix the problem. Changing your air filters on a regular basis can also help to prevent the issue in the future.

If the outdoor part of your air conditioning system is making noise, some common causes include problems with the condenser or with the refrigerant.

The Bearings Are Going Out in the Condenser Fan Motor

This component plays an essential role in circulating air through the condenser and over the coils.

The Fan Blades in the Condenser Are Out of Balance

This can happen when the condenser coils get dirty, which can mess with refrigerant pressure. That’s why it is wise for homeowners to schedule regular maintenance checks on their air conditioners. During this checkup, the technician will clean the condenser coil and make sure the system is in good working order.

Some items that can clog a condenser include pet hair and lawn debris. For example, if plants, bushes or trees are too close to the condenser, branches can grow into or around the unit and get in the way of the blades or other parts. Leaves, sticks, pollen and other debris from plants might also block the flow of air through the unit. Likewise, if your pets spend a lot of time near or on your outside air conditioning unit, the system can sometimes pull in their hair.

The Refrigerant Pressure Is Low

Examples of some situations that can lead to low refrigerant pressure and the noises that can result include a freon leak or dirty condenser coils.

As you can see, many of these issues are complicated and require in-depth knowledge of how these systems work. This is why many homeowners opt to contact a licensed professional to make their air conditioning repairs.

Another part of the unit you may hear about is the compressor. But, what is an AC compressor?

an AC compressor

What is an AC Compressor?

The compressor is one of the most important parts of your air conditioning system. It sits inside the outdoor portion of your AC unit—also called the condenser—and it pumps refrigerant throughout the system. Refrigerant is the substance that essentially makes your AC work by absorbing the heat in your home as it travels between the compressor and the inside portion of your AC unit (also known as the air handler).

Some signs that your compressor might be having problems include:

  • you are hearing weird noises coming from the outside part of your AC system;
  • you see fluid leaking around or inside the unit;
  • your electrical bills have started to rise, and you can’t find an obvious reason for the increase;
  • air isn’t coming out as strongly as it used to or as cool as it used to;
  • you notice frost or ice on the AC coils;
  • your compressor keeps overheating or
  • the circuit breaker keeps tripping.

Some of the most common issues that can cause these AC compressor problems include the following.

The Outside Unit Is Too Crowded

If you have plants, trees or other vegetation too close to your outside AC unit, they can keep the compressor from working correctly or can even start to grow into the unit. Your AC unit needs plenty of room to blow out hot air. Otherwise, the compressor will likely overheat and maybe even die. To fix this issue, trim away or remove any vegetation that is close to your AC unit and avoid using any kind of decorative cover that can get in the way of airflow.

The System Is Low on Refrigerant

This can happen if there’s a refrigerant leak somewhere in your system. The best way to find and fix this leak is to contact an air conditioning and heating professional. They can get your system up and running as quickly as possible.

The Condenser Is Dirty

Dust, dirt and other debris can clog up the condenser fan and other parts of your AC unit, which makes it more difficult for the compressor to expel heat and can wear the compressor down more quickly. This can lead to your AC compressor not working. The best way to deal with this is to contact a professional, who can clean off the condenser fan and other parts of the unit. They can also set up an air conditioning maintenance schedule, where they will take preventative steps to help you avoid this problem in the future.

an AC condenser fan that isn't working

AC Condenser Fan Not Working

If there’s a strange noise coming from the outside part of your AC system, then your AC condenser fan might not be working properly. Other signs of trouble include if the fan is not spinning or is running slowly. Some of the most common causes of condenser fan issues include:

  • The fan motor has gone bad. This usually happens as a result of the capacitor starting to fail.
  • The capacitor for the fan motor is bad. This is one of the most common reasons for AC condenser fan issues. The hotter it gets, the more likely it is for a capacitor to fail. However, if you hire an AC specialist to perform routine maintenance on your system, they can check when the capacitor is starting to get weak and can replace it before it fails completely. This preventative step is pretty affordable and can help save you from the headache of your AC giving out at the worst possible time.

One way to narrow down whether your AC condenser fan is the root of your problems is to try to eliminate other things that might be causing your AC issue. For example, replace your air filters to make sure a clogged filter isn’t preventing air from flowing through your system. Additionally, make sure that your thermostat is turned on. You can also check to see if a circuit breaker has tripped. A simple problem unrelated to your AC unit might have caused the breaker to flip to the “off” position, but if your breakers keep tripping, this could indicate a larger problem.

The best way to figure out what is going on with your AC unit is to contact a licensed heating and cooling specialist. These pros have the right experience, diagnostic tools and skills to diagnose the AC problem and to make any needed repairs quickly and correctly.

ABC Can Get Your Air Conditioner Working Again

It can be concerning when noises are coming from your unit or if your unit isn’t working correctly. No matter what issue you’re experiencing, ABC Home & Commercial Services can help. Our pros are licensed and will be able to quickly diagnose your AC problem. Then, we can get to work on making all the needed repairs.

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