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Common Types of Air Conditioner Noises


Having an air conditioner break down right in the middle of the summer is the worst! But you can prevent this from happening if you pay close attention to the warning signs that your air conditioning system gives you. Air conditioners tend to make unusual sounds when something’s amiss. If you can identify the problem before it gets worse, you won’t be stuck with the nightmare scenario of a broken air conditioner during a heat wave.

Is your air conditioner making noise? Our air conditioning repair experts have compiled a list of common air conditioner noises and what they mean, so you can catch any issues before they become bigger this summer.

Noises that Are Okay for Air Conditioners To Make

In order to spot a problem, you should have an understanding of what a healthy and well-maintained air conditioner sounds like first. You’re in good shape if you notice the following air conditioning noises: 

Low Humming Noises

A healthy air conditioning unit will make a low humming sound when it runs because of the fan and compressor. The fan is responsible for circulating air through the unit, while the compressor is responsible for cooling the air. The humming noise is caused by the vibration of these two components.

Light Clicking

Another healthy air conditioner sound is a light-clicking noise when it turns on. This is the relay switch engaging the compressor. The relay switch is responsible for controlling the current that flows to the compressor, and when it is engaged, it causes a light-clicking sound.

Light Rattling

The light rattling sound that an air conditioner’s outdoor unit compressor makes when it cycles on and off is caused by the pressure changes that occur inside the compressor. As the pressure inside the compressor changes, it causes the compressor to vibrate, which creates a rattling sound.

Noises that Are Not Okay for Air Conditioners To Make

If you hear the following sounds coming from your cooling system, you should call a professional HVAC technician as soon as possible:

Buzzing Sound

A buzzing noise could indicate a few different issues with an air conditioner. It could be caused by a failing compressor, a loose part inside the unit, or a clogged filter. A certified HVAC technician will be able to diagnose the problem and fix it within a few hours. 

Hissing Noise

A hissing sound can indicate a refrigerant leak in an air conditioning unit. Refrigerant is what allows an air conditioner to cool the air, so it is important to have the leak fixed immediately. And, since the refrigerant is toxic, there’s added importance to hiring a professional.

Rattling Noise

A loud rattling sound likely means there’s a loose part inside the unit, a clogged filter, or a faulty fan motor. Give an HVAC contractor a call to identify the problem.

Banging Noise

A banging noise can be caused by a faulty fan motor, a loose part inside the unit, or a clogged filter.

Clicking Noise

A clicking noise from an air conditioner could be caused by a faulty relay switch or a faulty fan motor. The relay switch is responsible for controlling the current that flows to the compressor, and when it is defective, it can cause a clicking sound. A faulty fan motor can also cause a clicking noise as it tries to start up or shut down. It is important to have a trained HVAC technician inspect your air conditioner to diagnose and repair the issue.

Call Robinson for High Quality and Affordable Air Conditioning Repair

Your AC unit is the most important appliance in your home during the summer. You can make sure it’s running properly and efficiently through the hottest days of the year with an annual tune up during the spring or early summer. Many of the problems we listed in this article can be prevented with regular maintenance. But, if it slips your mind to schedule a tune up, and you start to hear rattling, buzzing, banging, or clicking noises, Robinson is here to help you prevent a total breakdown. Contact Robinson Heating & Air Conditioning to schedule an air conditioner repair appointment.