5 Reasons Why Refrigerator Is Making A Knocking Sound

It’s normal for a refrigerator to make several types of sounds. After all, even the best fridges on the market aren’t entirely silent. However, a knocking sound coming from the appliance is not normal. Instead, it’s a sign that there’s a problem.

When you hear knocking sounds coming from your refrigerator, it’s likely because of an ice buildup around the evaporator fan. Besides that, the water pipes behind the fridge could be knocking on the appliance or the wall, causing similar noises. Next, check for an ice maker jam or if the sounds come from the fridge’s plastic parts. Lastly, the sound could also come from the compressor.

This guide will help you understand all the most likely reasons your fridge makes a knocking sound. The problem isn’t severe in many cases, and you can fix it quickly.

What Does It Mean When Your Refrigerator Is Making A Knocking Noise?

Before you begin troubleshooting the knocking sound coming from your fridge, there’s one crucial thing you must understand. Not all fridge knocking sounds are the same.

So, there’s no need to panic when you first hear that sound. In most cases, it’s not a severe problem.

Here are the most likely causes of that knocking noise you’re hearing in your fridge:

#1 Ice Around Evaporator Fan

The first thing to consider is a buildup of ice and frost around the evaporator fan.

The evaporator is the section of the fridge cooling system inside the refrigerator compartment. This part absorbs heat and releases the cold air needed for refrigeration.

Also at the evaporator is a small fan that drives cold air and distributes it throughout your fridge compartment. It consists of a fan motor and fan blades that spin like any other fan.

However, if ice and frost build-up around those fan blades, they can produce the knocking noise that you’re troubleshooting. That’s because the spinning fan blades will repeatedly hit the ice buildup, causing the noise.

One telltale sign that this is the root cause is that the knocking sound is rapid and continuous, mainly when the fan runs.

By removing the ice and frost buildup around the evaporator fan blades, you can resolve this issue. However, suppose the buildup is pretty severe and hard to remove. In that case, you must defrost the fridge and let the ice and frost melt away naturally.

Read: 4 Reasons Why Samsung Fridge Is Making Knocking Noise

#2 Water Pipes

Next, listen closely to see whether or not the knocking noise is coming from the water pipes.

Refrigerators with water dispensers and ice makers will connect to your household water supply through pipes and hoses. You’ll find those pipes and hoses behind the fridge, between the appliance and the wall.

The knocking noise you hear is likely coming from those water fixtures hitting the wall or the back of the fridge. This movement will happen if there are drastic changes in water pressure in the pipe or hose or a water hammer effect in action.

The solution to this problem involves a little plumbing. Firstly, check that the water connections are tight, as they should be.

Then, ensure that you mount the hoses and pipes securely to the wall or the back of the fridge. When those parts are secured to a flat surface, they can’t move and hit anything else.

Bottom line: when they can’t move, they can’t cause any knocking noises anymore.

Read: Your Fridge Is Not Cooling, Light Is ON? | How To Fix It

#3 Ice Maker Jam

Suppose your fridge model has a built-in ice maker. In that case, you’ll want to troubleshoot that part of the appliance as well.

Generally speaking, ice makers freeze ice cubes and push them into an ice bin. However, depending on the fridge brand and model you have, the ice might also slide out to a dispenser outside the fridge door.

However, knocking noises from this part of the fridge is likely a cube jamming the ice maker. 

When the ice maker’s moving parts struggle against a stuck ice cube, what you’ll hear is a repetitive knocking noise coming from that section of the appliance.

The fix for this issue is pretty straightforward: you must remove the ice cube that’s stuck. Careful, though, as it’s dangerous to stick your finger or anything else near moving parts to free the cube.

Instead, disconnect the fridge from its power supply before you try to free the stuck ice cube. Alternatively, you can also defrost the ice maker, so the stuck ice cube simply melts away.

Read: 3 Reasons Why Ice Maker Is Leaking Water On Floor

#4 Fridge Plastic Parts

Believe it or not, the plastic parts that line your fridge compartment can also cause the knocking noise that you hear.

Remember: your fridge has plenty of plastic panels and parts inside. Plus, there is plenty of space for air to get trapped behind the plastic rear panel and other sections.

Remember: your fridge doesn’t just stay cold all day long. Instead, several times a day, the appliance will run an automatic defrost cycle. During this time, a heating element somewhere around the evaporator will turn on to melt away any ice or frost buildup.

So, as your fridge repeatedly warms up and cools down throughout the day, all air inside will expand and contract. That will cause the occasional ‘pop’ sound that’s loud enough to sound like knocking.

In this case, there’s nothing you can do to fix it. These kinds of noises don’t point to any real problem. Instead, it’s a natural part of the fridge’s wear and tear after being in use for many years.

Read: Does Fridge Need To Be Level And Why?

#5 Worn-Out Compressor

Once you finish ruling out all of the above, then it’s time to consider that your compressor might be the source of the noise.

The compressor is the heart of your fridge’s cooling system. It compresses the refrigerant and drives it throughout the sealed cooling system.

Fridge compressors typically last more than ten years. However, when yours has a knocking sound coming from it, that means it’s going bad, or there’s a faulty component inside.

Unfortunately, you cannot troubleshoot or repair the compressor by yourself. 

The US Environmental Protection Agency (EPA) says that only someone with the necessary training and certifications can troubleshoot a sealed system like the one on your fridge, which includes the compressor.

So, the only step you can take is to contact a qualified and certified technician to troubleshoot your compressor. They’ll likely advise that you replace the faulty compressor with a new one.

Depending on how long you’ve had the fridge, it might be a better idea to upgrade to a new fridge entirely when this happens.

Read: How Do You Know If Refrigerator Compressor Is Bad?

Frequently Asked Questions (FAQs)

Here are some other frequently asked questions (FAQs) that you’ll find helpful to understand the knocking sound coming from your fridge.

What Is The Fastest Way To De-Ice A Fridge?

The fastest way to thoroughly de-ice your fridge is to force its defrost cycle to begin. That will activate the heating element that melts all ice and frost build-ups inside. 

The precise steps to do this will differ between fridge brands and models, so you must refer to the user manual to learn how to do this.

Can You Defrost A Freezer Without Turning It Off?

Yes, you have several options to defrost a freezer while keeping it on. Firstly, you can force the fridge’s defrost cycle to start. Besides that, you can fill a pot with boiling water and let it sit inside the freezer. The steam will quickly melt excess ice and frost inside the freezer, especially any around the evaporator fan that causes a knocking sound.

Is It Safe To Use A Hair Dryer To Melt Ice Around The Evaporator Fan?

No, it’s not safe to use a hairdryer anywhere inside your refrigerator. That’s especially true around the evaporator fan. The fan blades are made of plastic, so exposing them to a blast of hot air from a hairdryer will warp or melt the fan blades.

How Do I Stop My Ice Maker From Making Noise?

You can stop your fridge ice maker from making a knocking noise by removing any ice that’s jammed in its moving parts. For the time being, turning the ice maker off will also stop it from making knocking sounds until you can fix it.

Can Fridge Compressor Be Repaired?

Yes, in some cases, a technician can repair a fridge compressor. However, if yours is making knocking sounds, it’s safe to assume the compressor has reached the end of its life. Therefore, you’re several times a daybetter off replacing your compressor with a new one.