Why Is My AC Making Loud Noises?

The air conditioning unit at your home helps you maintain cooler indoor temperatures during the hot summers. However, like any piece of machinery, an AC needs routine maintenance and servicing. It might also occasionally require repairs. Sometimes, negligence in these areas can cause the AC to malfunction. One of the early signs of an AC malfunction is a loud noise coming out of it. When you hear a noise from your AC, it is best to have a professional HVAC expert look at it. Here are some common types of noises that air conditioner units typically make and their causes.


Rattling is a fairly common type of noise that comes out of an AC. If you hear a rattling or shaking noise coming out of your AC, this likely means that there’s a problem with the AC components. When one or more components become loose, the AC begins to rattle whenever you turn it on.

If the loose components are on the outside, such as screws or the ducts, you can tighten them on your own and eliminate the noise. However, if the rattling comes from inside the AC unit, you need a professional HVAC expert to resolve it.


A buzzing noise means that there’s a problem with one of the electrical components in your AC unit. One of the key problems that cause buzzing is a failing motor. Buzzing may also be caused by debris in the outdoor or indoor AC units or loose components in the air conditioning system. You may want to check the AC unit and the ducting to carry out an inspection on your own.

If you hear a buzzing sound and the AC does not sufficiently cool the indoor, this could mean that there’s a refrigerant leak. In such a case, you will need to fix the leak and then have the refrigerant recouped to the optimal level.


Clicking is a distinct and common type of noise made by an AC unit. In many AC units that have aged beyond 8 to 10 years, it is common to hear a clicking sound when you turn the AC on and off. However, a more persistent clicking could mean that there’s a more serious problem with the AC.

In some cases, a small object may get stuck in the AC unit and hit against the fan blades. This can create a consistent and annoying clicking sound. Alternatively, a clicking sound could also mean that an electrical component within the AC unit has malfunctioned and come loose. It is important to have this looked into as soon as possible or the problem may get worse quickly.


If you hear a loud banging noise coming out of your AC, you probably have a major problem. A banging noise is most commonly caused by a problem with the compressor. When a component becomes loose inside the compressor, it starts to bang against the compressor’s outer shell.

You can inspect the compressor closely to ensure that the noise is coming from the compressor. If it is, you will need professional help. In the case of a compressor malfunction, you will need a full replacement in most cases. On average, AC compressor replacement costs around $850.


If your AC unit was repaired and had its parts replaced, a whistling sound may be caused by a compatibility issue. A common cause of whistling noise is a problem with the ducts – the ducts are either too narrow or they are damaged, causing air to escape.

If your AC’s filter hasn’t been cleaned in a while, it can become clogged. This can also create a whistling noise. You can inspect the air filter to see if it is full. A quick filter replacement can resolve the problem and eliminate the noise.

Why Hire A Professional HVAC Expert?

In most cases, it is possible to troubleshoot loud noises from an AC unit on your own. However, you run the risk of further damaging the AC in doing so. A far better way is to hire a professional expert to look at the AC components and find the cause of the noise. A professional HVAC expert will be able to identify the problem quickly and suggest the most efficient solution.

Contractors for AC Repair in Greenville, SC

Here at General Air, we handle a huge range of AC repairs on a routine basis. If your AC is making loud noises, you must have it looked into as soon as possible. A timely troubleshooting will eliminate the problem at the earliest, preventing it from getting worse and costing more in the long run. Contact General Air today, our Greenville technicians and experts will be with you in no time.

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