What to do if your air conditioner is making a weird noise

What to do if your air conditioner is making a weird noise

fix air conditioner noise


Note: The information in this article is intended to provide guidance on the proper maintenance and care of systems and appliances in the home. Not all of the topics mentioned are covered by our home warranty or maintenance plans. Please review your home warranty contract carefully to understand your coverage.

Many things occurring inside your air conditioner (A/C) unit can cause weird noises. However, these loud noises almost always indicate that various components like the thermostat, air filter or compressor are wearing out and that your A/C unit is likely on the verge of some kind of failure, potentially leaving your home hot in the summer heat. 

If your air conditioner is making strange noises, it’s important to act on the issue prior to purchasing a home warranty, as the issue could be deemed as a known pre-existing condition. If you purchase a home warranty, though, and your A/C then experiences a mechanical failure, you’ll be able to initiate a claim.

This article covers the ins and outs of the weird noises that air conditioners can make, some of the likely causes and what you can do about it.


Understand what’s normal and not normal when it comes to A/C noise

Make sure you understand the various noises that naturally come out of your air conditioner. For example, it can be perfectly normal for your air conditioner to make an “airplane takeoff” noise upon startup. When in operation, air conditioners tend to make steady blowing noises. You may hear clicking noises briefly after a complete cooling cycle as the machinery comes to a stop.

If the sounds you hear fall outside the standard and expected sounds made by an air conditioner under normal operation, pay close attention to whether the noise changes over time and what the unit does when starting. Try to describe the sound, identify when it occurs and see if you can find out where in the system it’s coming from.


Different types of noises your air conditioner can make (and what they mean)

Anyone who has ever been around appliances knows they can make quite a variety of sounds, from banging noises, hissing noises, squealing noises, humming noises, clanking and more. Some noises occur during normal operation, while others are a sign of a broken part or that the appliance is about to stop working. In this case, you should call a repair person immediately.

When it comes to air conditioners, loose parts can shake around, causing clunking or rattling noises. There can also be problems with airflow and compression, leading to whistling or other strange sounds. You can’t always tell what’s wrong by the sound, but often, you can get a good idea. 

Air conditioner is making a pulsating noise

Pulsating is an alternation between loud and soft sounds coming from your air conditioner. This alternation may have a rhythmic quality to it. 

There are many moving parts inside the compressor. If those parts aren’t properly insulated, the movement can’t be dampened or subdued. This can make it easier to hear the motion of parts like the fan motor, blower or condenser coils, and that motion can result in resonance — the entire machine pulsating rhythmically. 

If your air conditioner is on a plastic pad, the compressor’s motion may transform and create pulsating. Other causes include motion transfer from the refrigerant line if it’s in direct contact with the wall instead of insulated. If the sound is more like a metallic whirring, it could be a loose condenser fan or fan blade.

While it can be a good idea to start troubleshooting on your own, if you can’t identify the problem without disassembling your unit, it’s time to call a technician for help. 

Air conditioner is making a loud popping noise

If cracking, popping or clicking sounds happen when the air conditioner is first turned on or has completed a cooling cycle and then goes away, there’s nothing to be concerned about. These sounds can occur naturally as the metallic components expand or contract due to temperature changes. 

However, if the sound continues or is particularly loud, you may have a problem on your hands. Sometimes, the formation of ice inside the unit causes this sound, which can happen if the unit is not draining properly or there is a failure of sensors that cause it to turn off to thaw. 

Water in the unit, even unfrozen, could also cause these sorts of sounds. Air conditioners need to drain built-up moisture properly, or the moisture can get inside more sensitive components and lead to damage. You should turn your air conditioner off and unplug it before looking it over for excess moisture. If debris clogs the drain, you can probably remove it yourself. Otherwise, it’s time to call in a professional. 

Air conditioner is making a gurgling noise

Gurgling or bubbling noises might indicate problems with the refrigerant line. If the lines aren’t properly sealed, air can be trapped in with the liquid coolant due to a refrigerant leak, leading to this sort of noise as the air bubbles move through the system. 

If your air conditioner is making gurgling sounds, it’s likely still safe to operate, but it’s a good idea to call in an expert to make sure. A technician can also replace the coolant lines if the problem or noise is particularly loud. 

Air conditioner is making a loud buzzing noise

If you hear buzzing noises coming from your unit, the odds are that it’s an electrical problem. If there’s power flowing to the contactor switch but doesn’t pass through it to start the compressor, for example, this results in loud buzzing. 

Capacitors, compressors and other components can also buzz due to getting power but not being able to put that power to use due to some sort of fault.

Buzzing might be non-electrical, as well. In such cases, it often has similar causes as pulsating noises, such as loose parts. After all, very fast pulsating sounds the same as buzzing. Buzzing may also occur if your unit becomes frozen. It’s a good idea to call in a repair professional for help.


When you should call a professional for your air conditioning unit

Air conditioner repair is best done by an experienced HVAC professional. Professionals understand the complete workings of air conditioning units, including potential hazards and what safety precautions to take to avoid them.

Refrigerant lines, for example, can be dangerous if handled improperly, even cutting off oxygen to your vital organs if inhaled. Mishandled electrical components can cause shock. This can happen even if the device is unplugged since components like capacitors can hold a voltage. 

If you forego caution and attempt to disassemble and repair your unit on your own, you run the risk of damaging it further due to a lack of understanding of how the components work. It’s always best to leave it to the professionals. Not only is it safer, but also you can rest assured that professionals handle the problem correctly and you aren’t going to make it worse, driving up the cost of the fix.


A/C repair is made easy with a home warranty

An air conditioner breakdown is never fun, particularly in the heat of summer. If you live somewhere hot and humid, it makes for a particularly miserable time. Moreover, finding a qualified repair person can feel nebulous and stressful, and you’re likely to be surprised by an unpleasant bill at the end of it all.

A home warranty plan not only saves you a great deal of the repair cost but also the warranty company uses their vetted network of expert service professionals to find you the best person for the job. In fact, even if you need to replace the whole air conditioning unit, your home warranty will more than pay for itself by covering a large portion of the cost for the new unit. Check out the Cinch protection plans page to learn more about what home warranty plans have to offer. You can also get a free quote today and learn just how affordable home warranty coverage can be.


Weird noises can be caused by many things occurring inside your air conditioner unit and may indicate problems requiring a technician’s help.

Your home protection is ready and waiting!