Air Conditioner Crackling? Here’s Why & What to Do

Air Conditioner Crackling? Here's Why & What to Do

Have you ever heard the crackling sound that some grasshoppers make? Is your air conditioner crackling just like that? If so, it could be a little unnerving.

However, sometimes it’s quite normal for your air conditioner to make a crackling sound. It could be normal expansion and contraction as the unit changes temperature, it could be the sound of vents moving up and down, or it could be something more serious like your unit freezing over.

Keep reading and we’ll explore the most common causes of crackling or popping sounds from your air conditioner and what you can do to address them.

What You’ll Need

For the most part, you won’t need any tools for the issues mentioned below. However, you may need the following.

  • Screwdriver
  • Soft cloth
  • Brush
  • Spray bottle
  • Dish soap and warm water

Why Your Air Conditioner Is Crackling

Whether you have a central system, a portable, a window air conditioner, or a split system, any one of them can crackle for different reasons.

So if you’ve ever turned on your air conditioner and heard a strange crackling or popping sound, you’re not alone. These noises can be alarming, but fortunately, they’re often easily fixable. 

Normal Expansion & Contraction

One of the most common reasons for crackling sounds from your air conditioner is simply normal expansion and contraction. When your air conditioner cools the air, the metal parts of the unit will naturally contract as they get colder. This can create popping or creaking sounds as the metal shifts and settles into its new position.

While these sounds may be annoying, they’re usually not cause for concern. If you’re hearing popping sounds that seem to be coming from inside your walls or ceilings, it’s possible that the ductwork is expanding and contracting as well. This is also a normal occurrence and should not be a cause for concern.

Dirty Filters

Another common reason for popping or crackling sounds from your air conditioner is a dirty filter. When the air filter in your air conditioner is clogged with dust and debris, it could create popping sounds as the unit works to cool the air.

To avoid this problem, it’s important to follow your air conditioner’s filter maintenance schedule. This usually involves changing the filter every one to three months, depending on how often you use your air conditioner, how dirty the air in your home is, and what type of air conditioner you have. 

Your Air Conditioner is Icing Over

How to Fix a Portable Air Conditioner That Freezes over

If you’re hearing crackling sounds and your air conditioner is also not working properly, it’s possible that the unit is icing over. This can be caused by a variety of factors, including low refrigerant levels, dirty coils, or blocked airflow.

What Causes Icing

When your air conditioner is icing over, it means that the evaporator coil is getting too cold and causing moisture in the air to freeze. This ice buildup can cause your air conditioner to stop working altogether, as well as create popping or crackling sounds.

Do the following to fix an air conditioner that’s frozen over.

Step 1

Unplug your air conditioner and let it thaw completely.

Step 2

Once the ice has melted, check for dirty coils and blocked airflow.

Step 3

Use a soft cloth or brush to remove loose dirt and debris from the coils and then mix together some warm water and dish soap in a spray bottle to clean them.

Step 4

In some cases, your air conditioner may ice over due to low refrigerant levels. If you suspect that’s the problem, you’ll need a professional to address the issue.

Loose Parts

Do the crackling or rattling sounds seem to be coming from inside your air conditioner? If so, it’s possible that there are loose parts in the unit. Over time, the vibration and movement of the air conditioner can cause screws, bolts, and other parts to loosen and rattle around.

To fix this problem, here’s what to do.

Step 1

Unplug, or power down the unit. 

Step 2

Carefully inspect the inside of the air conditioner. Check for any loose parts and tighten them up as needed. Be careful not to overtighten, as this can cause additional problems.

Wiring Issues

If you’re hearing crackling or popping sounds that seem to be coming from the electrical components of your air conditioner, it’s possible that there’s a wiring issue. Loose or damaged wires can create arcing or sparking sounds, which can be dangerous if left unaddressed.

Here’s what to do.

Step 1

Power off and unplug your air conditioner

Step 2

Access the inside of the unit according to type and manufacturer’s instructions.

Step 3

Carefully inspect the wiring, looking for any loose or damaged wires. Tighten and replace them as needed. If you’re not comfortable working with electrical components, it’s best to call a professional.

Something Stuck in a Vent

A crackling sound could be the result of something stuck between one of the louvers or vents of your air conditioner. Even something like a stiff piece of paper or cardboard could make a clicking or crackling noise as the fan blows through the vents.

Inspect all of your air conditioner vents, looking for anything that may be stuck in them.


A crackling air conditioner is probably irritating, but sometimes it might be normal, meaning there’s really nothing you can do about it. That would be the expansion and contraction that can happen as components heat up or cool down.

Otherwise, as mentioned above, there are several other reasons for crackling or popping noises. To recap, they are:

  • Dirty filters
  • An air conditioner that’s icing or freezing over
  • Loose parts
  • Wiring issues
  • Something stuck in a vent

Thankfully, there’s something you can do to fix each of these, so hopefully one of them solved the issue for you.

While you’re here, why not check out our related posts below? Perhaps we can help you with something else.

I've been helping homeowners with appliance repair since 2016. Starting out as an enthusiastic amateur, I've since worked with many Appliance, HVAC, and DIY experts over the last 7+ years. My mission is to help fix your appliances and prevent future issues - saving you stress, time, and money. Visit my author page to learn more! Read more