Refrigerator (Fridge) Makes Constant Knocking Noise: 7 tips

refrigerator (fridge) makes constant knocking noise

Normally, the freezer doesn’t make a sound at the early stage. But some Whirlpool, Lg, Samsung, GE, and Frigidaire freezer/fridges/refrigerators are making constant knocking noises. Loud humming, popping, buzzing, hissing, sizzling, clunking noises, etc. may be created.

Some parts of the freezer are the reason for creating that noise. If you have faced these types of problems with your refrigerator, sometimes you don’t take it seriously.

Normally it is seen as a low sound in the good condition of the refrigerator. But if you see an unexpected or abnormal sound coming from your refrigerator, you should take specific steps for solving that issue.

If you don’t take that sound seriously, your fridge will damage quickly in the future.

Is a Noisy Freezer or Fridge Dangerous?

The cooling function of the refrigerator creates normal noise. This type of sound is low and you don’t need to stop that.

When there is any problem in the condenser fan or motor, evaporator fan, and compressor, it creates an uneasy sound that is bad for the refrigerator. This type of sound may be a sign of a faulty fridge.

If you see that the sound is higher than normal, you should take professional service. But if you find that the sound is normal, then you can easily reduce it by following some techniques.

Now you may ask me how to understand the exact source of noise in any refrigerator?
To get the answer to this question, you need to read the next part.

If you can easily know the noise source, you should easily take the required steps to remove that noise.

For knowing the exact noise problem, you need to know the basic idea of any refrigerator.

Don’t worry…

You don’t need to be a mechanical person to understand the function of the fridge and solve common problems.

Here I will share the basic working function and some basic parts of a common refrigerator so that you can easily understand the real problem of a fridge.

After sharing that information, I will also discuss the common source of popping noise in a refrigerator.

If you can understand the working activities of a refrigerator, you can also easily find the problem of the noisy fridge.

How Does a Refrigerator Work (Process Diagram)

To know the working function/operation of a normal refrigerator, you should know some common parts of a fridge. Such as:


It is one kind of fluid that is circulated in the refrigerator.


compressor for refrigerator (fridge)

Compressor type refrigerator creates noticeable noise. (source)

So for better understanding, you should know the function of the compressor below.
There are two functions of a compressor for a refrigerator/fridge. Such as:

One: Create the flow of refrigerant
Two: Create the pressure difference of that refrigerant

For creating the pressure difference, the compressor includes a crankshaft, connecting rod, piston, cylinder, inlet valve/suction, discharge valve, etc.


It is like a tube that is situated behind the refrigerator. It is the place where the refrigerant is cooled down and converted into liquid refrigerant.

An additional fan is adjusted near the side of the condenser coils so that the hot temperature goes out to the outside of the condenser.


It has two main functions. Such as:

One: Absorb heat surrounding the area
Two: Transfer liquid refrigerant to vapor refrigerant.

Working Principle of Refrigerator and Freezer (Diagram)

working principle of refrigerator and freezer with diagram

In this image, I have tried to indicate some parts of the refrigerator and you should understand their function.

To know more, continue reading…

For the movement of the piston of the compressor, it receives low-pressure vapor refrigerant. This Refrigerant is also compressed for the pressure of that piston.

After compressing the refrigerant, there is high pressure in the refrigerant substance. For this pressure, there is a high temperature in the refrigerant substance.

At the same time, the suction valve is closed and the discharged valve is opened. Now the vapor refrigerant goes to the condenser.

Here, the temperature of the refrigerant is higher than the surrounding internal temperature of the condenser. That is why condensers remove heat from the refrigerant (see the image). To remove this heat quickly, a fan is adjusted near the condenser.

N.B: When refrigerator fans have some problem, it may create unexpected noise. Besides, excess air pressure/airflow/water pressure of water supply lines may create noise. The water filter may also create the noise of water hammers. The water dispenser may make a banging sound in any situation. For mechanical problems in the water valve, hammering/bubbling/gurgling noise may be created. When the push switch of the refrigerator is off or on, you may hear the noise. the fridge may make a loud sound when first turned on. It also makes a clunking noise when it shuts off accidentally.

After cooling this refrigerant, it is gradually cooled and turns to liquid in the condenser. Next, this liquid refrigerant goes to the filter section.

Here moisture is absorbed in the filter. After that this refrigerant goes to the capillary tube (expansion device) where the pressure of the refrigerant turns from high to low.

This liquid refrigerant with low pressure and temperature goes to the evaporator. So in the area of the evaporator, there is a low temperature for this refrigerant.

This is why the evaporator coils absorb heat from the fridge (see the image). After absorbing heat, a refrigerant with low temperature converts to vapor refrigerant (low pressure).

N.B: For quick heat absorption, there is an attached freezer fan on the side of evaporation. Noise may create when this fan is not properly working.

This low-pressure vapor refrigerant again comes to the compressor and it is circulated again. Thus this system continues and removes heat from the refrigerator.

If you read above all the information, you can easily understand the notes below where I have described the noise issue and the solution for a fridge.

How to Find Out and Fix the Refrigerator Knocking Noise

You have already understood the working principle of a common fridge. Now you should fix the noisy fridge after finding the exact reason. Here, I will discuss some common reasons with solutions.

Point 1: Create a Gap

When you install a fridge in any location, be sure that it is not attached or touching any wall surface of a room. Impact noise may transfer through the wall when a refrigerator has a connection to any hard surface.

So the better idea is that you should keep a gap around the refrigerator so that any vibration sound can’t flow through any hard surface.

If the fridge is attached to a wall, move the position of the refrigerator and make a gap around it. You should also check the electrical cord or outlet that has a minimum distance or not. If you see that there is no gap, you should keep them some distance.

Point 2: Place Sound-Reducing Material Under the Fridge

During running the fridge, it may create vibration and create some sound. This sound may pass through the floor easily.

To create a barrier between a refrigerator and the floor surface, you need to keep acoustic elements under the refrigerator.

According to your budget, you can use the strong sound-reducing elements that I am sharing now.

a. Placing of Anti Vibration Pad
You can get an anti-vibration pad from any local market. This type of pad instantly stops machinery vibration. Besides, you can also use sound deadener foil under the fridge.

b. Placing of Foam Mat
This type of rubber mat/panel has high anti-vibration capability. Some mats also have adhesive so that you can adjust them on any surface. So you can place it under the refrigerator if you choose it.

c. Placing of Soundproof Rugs or Underlayment or Blanket
You can place a fridge on a thick blanket or rugs. You can also use acoustic underlayment if possible. Because this type of underlayment reduces sound vibration too.

d. Using of MLV (Mass Loaded Vinyl)
MLV is great for stopping the transfer of sound waves. After collecting the MLV, you can cut it easily according to your measurement. If you prefer this MLV, you can place it under the fridge for removing vibration noise.

Point 3: Place Acoustic Material Behind the Fridge

You can use Rockwool or mass-loaded vinyl to the backside of the fridge. Maximum noise comes from the backside because the compressor is situated there.

It will be better if you collect a board and attach the acoustic material like MLV and finally attach that board to the back wall side of the fridge.

Point 4: Check the Compressors/Linear Compressors

This part may make knocking sounds and you should inspect it to avoid the compressor knocking noises on the fridge. If you don’t find the location of this area, you should see the image.

If you are unable to inspect the compressor, you should take help from technicians. If abnormal noise comes from the compressor, you need to contact the supplier or manufacturer. Because only registered people have the right to fix noisy and defective compressors. For compressor replacement, you can take the help of a professional person.

Point 5: Check the Condenser and Evaporator Fan

Sometimes noise may be created from the blades of the evaporator and condenser fan of a fridge.

If you are used to opening the fan, you should check whether the fan blades are working fine or not. If any dust is stored in the evaporator fan cover and dirty coils, you should clean it immediately. If the fan still creates noise, you should replace it.

Point 6: Clean the Total Fridge

My recommendation is to use dust cleaner (high-pressure air) for cleaning the required area.

By using a vacuum cleaner, you should clean the dust of the freezer compartments with a soft brush or vacuum brush attachment.

You should focus on the area of the condenser, evaporator, and compressor. You may try to clean other appliances in the fridge if possible.

Point 7: Replace a New One

If you have used your running fridge for many years, that fridge is creating a regular irritating sound, and it is expired, then you should think of new models immediately.

You Should collect the silent or quietest fridge from the marketplace.

Is the Refrigerator/Freezer Making a Buzzing Noise Every Few Minutes?

Sometimes this type of buzzing sound may be created after being left open. When the compressor, ice maker, or fan is not working properly, this noise may be created. Call an expert to solve this type of noise.

N.B: If possible, you may use the refrigerator cabinet for reducing effective noise.

My Viewpoint

In summary, I will tell you that you should know basic knowledge of the working principle of the fridge. It will be better if you know the different parts of the refrigerator.

For easy understanding and finding the noise source, I have shared some basic parts with specific problems.

I have also tried to share the information with images so that you can get the point easily. You should check the leveling legs of any refrigerator because noise may be created by improper leveling of the fridge.

Sometimes, you may hear the sound of falling ice cubes. If you read the solutions (shared in this post), I think you can learn and find the exact sound problem from the fridge.

You should also read the answers (FAQ section) for more information.

FAQ: The Freezer or Fridge is Making Loud Humming Noises

Is the Brand New Refrigerator/Fridge Making Knocking Noises?

The refrigerator doors may create a squeaking or popping sound or whistle sound when you close the door.

In the cage of the new fridge, rubber material (gasket) may be the reason for that loud refrigerator noise.

When this seal of the gasket and upper hinge are tightly closed, then it may create sound. The freezer and other refrigerators may make noise and start thawing when the door is closed. After a few days, when this gasket will be flexible, that sound will be closed.

If the Fridge Constantly Makes Knocking Noises, What to Do?

First, you should read the entire writing of this post. You should read some possible ways that you may follow to find the source of the sound.

Then check the control unit carefully step by step. You can get help finding the real noise source from a professional repairer.

Why Does a Fridge/Freezer Make Noise at Night?

In the nighttime, the environment stays in silent mode. This is why you may hear the sound from a noisy fridge.

However, you should check the total process (shared in this blog), especially the circulation fan of the condenser and evaporator. For that reason, a deep freezer may also make a loud humming sound in any situation.

What Does a Bad Evaporator or Condenser Fan Sound Like?

Condenser or evaporator fans may create a chirping or clicking sound when it has some problem.

Can a Noisy Fridge or Refrigerator Cause a Fire?

If the noise comes from the compressor and overheats, it may cause a fire. So you should check that the compressor is heated or not when it creates noise.

Why Does the Sound of the Freezer Like it’s Sizzling?

When water drips in the defrost heater during the defrost cycle of the fridge, it may create sizzling noise.

Besides, if the freezer/freeze is making a banging noise after defrosting, you should fix it. Water dripping noise may be created by the problem of the drain pan.

So you should clean that area of the drain pan with soapy water. You should be careful of any kind of sound that may be created from your fridge and at the same time you should take the necessary steps as required.

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