Why Is My Refrigerator Making A Knocking Noise?

While it’s operating, a refrigerator will make a variety of noises. From buzzing, humming, and gurgling, these noises are a normal part of the every-day operation of your fridge. However, when your refrigerator makes a disturbing banging or knocking noise during operation, you may want to call a technician ASAP.

The knocking noise that you’re hearing may be coming from the cooling fans or the compressor of your refrigerator. Unfortunately, this isn’t normal, and it means that there is a malfunction of some sort.

In this article, we will discuss why your refrigerator is making a banging or knocking noise, and what you can do to fix it.

What makes the knocking noise in your refrigerator

There are three probable sources of the knocking noise you’re hearing inside your refrigerator. These are the (1) evaporator fan, (2) condenser fan, and (3) the compressor.

It could be that there is a defect in your fridge, or they may be a loose part inside of your unit. If you’re lucky, the parts may just be too dirty to function. Whatever it is, it should be fixed quickly as this malfunction can affect your refrigerator’s performance negatively.

Malfunctioning evaporator fan

If the knocking noise is coming from inside the refrigerator, and it is accompanied by a warmer than usual temperature in the interior, then this is probably the case.

The evaporator fan is responsible for distributing the cold air throughout your refrigerator. If you do not fix this, your no frost refrigerator won’t cool properly.

The fan motor itself may also be malfunctioning; there may be something obstructing the evaporator fan, or the fan blade may be bent out of shape and is hitting something which is causing the knocking sound.

How to fix a malfunctioning evaporator fan

The first thing you’ll want to do is to defrost your refrigerator to melt the ice (if any) that is blocking your evaporator fan. If that doesn’t solve your problem, then you’ll have to take off the panel of your fridge so you can access the evaporator fan.

If the evaporator fan is dirty, just take it off and remove all of the gunk out with a brush. Try to spin it a few times, there may be something caught around the fan that is preventing it from spinning properly.

Warning: Do not submerge the evaporator fan in water as there are electronic parts inside it.

If the fan is bent out of shape, then it won’t do you any good if you try to bend it back into shape. It will just come out unbalanced and will still make a banging sound. You should replace the evaporator fan right away.

When the fan motor is the one causing the problem, then you’ll have no other choice but to have it replaced by a technician. They can also check for loose parts inside the evaporator fan.

Malfunctioning condenser fan

If the s knocking noise is coming from the back of the refrigerator, then it may be the condenser fan that is causing the issue.

The condenser coils “transfer” the heat from inside the refrigerator to its exterior. Since these coils get hot, they need to be cooled somehow. In older refrigerator models, the condenser coils are air-cooled, hence why they are exposed at the back of the fridge.

For newer no frost refrigerators, the condenser is hidden at the back of the fridge, which necessitates the help of a fan to cool it down.

During its operation, the condenser fan accumulates dust, grime, and lint that can hamper the fan’s spinning. The fan blade itself can also be bent if a foreign object somehow gets caught while it is spinning. These can cause the knocking noise you’re hearing from your refrigerator.

How to fix a malfunctioning condenser fan

Unplug and move your refrigerator where you’ll have easy access to its backside. Next, remove the rear panel (if any) so you can have access to the condenser fan. If it is dirty, take the fan off and remove the grime out with a brush. Try to spin it a few times, there may be something caught around the fan that is preventing it from spinning properly. Check for loose parts as well.

Warning: Do not submerge the condenser fan in water as there are electronic parts inside it.

As with the evaporator fan, don’t try to bend it back into shape if it is warped – have it replaced right away. The same goes for a faulty condenser fan motor.

Malfunctioning compressor

If you find no fault in either the condenser fan or the evaporator fan, then the squealing noise is most likely coming from the compressor itself.

This is problematic as the compressor is the “heart” of the fridge, and if there is any problem with it, it will mean expensive repairs on your side or complete replacement of your refrigerator.

The most likely reason may be a malfunctioning crankshaft inside the compressor. It could also be a loose part, or the compressor itself has come loose. Whatever it is, the best course of action is to have it diagnosed by a technician.

How to fix a malfunctioning compressor

If the problem is caused by loose parts, or if the fix is relatively inexpensive, go have it fixed.

However, if the fix entails a replacement of the compressor itself, don’t even bother. The cost of replacing a compressor is so expensive that you would be better off just buying a brand new refrigerator.


In summary: the knocking noise your refrigerator makes is a serious matter that should be dealt with ASAP! Call a technician to properly diagnose your problem.


1 thought on “Why Is My Refrigerator Making A Knocking Noise?”

  1. I appreciate your explanation when you told us that the noise we are hearing from the refrigerator might be due to the condenser fan accumulating dust, grime, and lint, which has been hampering the spinning of the fan. Coincidentally, it seems like my fridge at home needs a new condenser fan soon since it has been causing us problems at home these days so I was advised to have it replaced. I’ll keep this in mind while I look for appliance stores around Hartford that sell the fridge parts I need as replacement.


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