Air Conditioner Noise | General Heating and Air Conditioning

Why is my air conditioner so loud?

Carrier Air Conditioner
Air conditioners are machines made up of moving parts; therefore, it is natural for some noise to happen while your unit is running. However, when you reach a higher noise frequency, there may be an issue at hand.

There are a few common answers to the question of, “Why is my air conditioner so loud?” First, these can depend on what make and model of air conditioner you have. Additionally, the type of noise your AC unit is making means a different issue is likely causing the problem with your air conditioner.

Common Sounds (and Causes)

When the noise your unit is making seems to move beyond a “normal” noise that an AC unit would be making, that’s when you want to look at the possible cause. One thing to keep in mind is that older units typically make more noise.

Some noises have simple fixes, such as your unit may have parts that require lubrication or a fan blade may be dirty. These issues are usually caught during annual maintenance by an HVAC professional of your machine.

However, other noises, such as the noises outlined below, can require more immediate action for your unit. If you hear any of these sounds, you want to turn off your unit to eliminate further damage. Next, for serious issues, you want an HVAC professional to diagnose the issue and fix it.

Some common noises a unit can make are:

A Grinding Noise: This is typically a more serious issue with your unit. A grinding noise usually signifies a problem with one of the fan motors on your unit. To solve this problem, you need to identify what could possibly be going wrong with the motor.

A Rattling Sound: If you hear a rattling noise, this could mean several different things. If it is in your outdoor AC unit, something, such as sticks, rocks, or other debris, could have fallen through the vents. On a similar note, this type of noise could also signify loose bolts, screws, or fasteners. These are the two “simple” diagnoses.

A less simple diagnosis is that this sound could also come from a part of your AC unit called the compressor. Basically, as the compressor begins to age, it can get louder and make noises. These noises would be the first sign that there is an issue with your compressor.

A Noisy Fan: There are several issues that can arise from the fan in your AC unit. If there is debris on or around the fan, this can cause your unit to be noisy. Additionally, blades on your unit could be bent, and even the slightest bend on a blade will cause noise to occur.

A Hissing Noise: This is usually a serious issue with your AC unit only when it is coming directly from the AC unit. If it is coming from the ductwork, this is not as serious. This noise coming from the AC unit itself will typically signify a refrigerant leak. This is something that an HVAC professional needs to handle.

Noise could also be coming from your AC ductwork, which has its own category of possible issues.

How can you prevent these issues?

There is no sure way to prevent any issue from happening, but there are some ways that lessen the probability that your air conditioner will have issues.

Regular Maintenance: Having your unit regularly checked by an HVAC professional allows any issues your unit may be experiencing to hopefully be caught before they turn into larger issues.

Change Your AC Filter: You should change your AC filter routinely. If this is dirty and clogged, then it is not operating as it is meant to. When you purchase a new filter, it will include a manufacturer’s recommendation on how often the filter should be changed. This is just a recommendation, so if you notice your filter getting clogged, you want to change it more frequently.


If any of these problems sound familiar to you, contact our HVAC professionals at General Heating and Air Conditioning or call us at (608) 271-3900 to help you figure out what may be wrong with your unit. Your home comfort is our priority.

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