How to fix refrigerator knocking noise

When summers are just around the corner, nothing freaks you out more than unexpected refrigerator problems. Especially when your refrigerator begins to make a knocking noise. In which case, this is the high time that you should seek out the root of the cause otherwise it could end up costing you a fortune.

However, fear not as we have all the bases covered, from the initial warning signs to the possible fixes.

The most likely reason for your refrigerator to make a knocking noise is down to the compressor or condenser fan.
This is commonly a case of the fan becoming blocked from a build up of dust, reducing air flow, resulting in a knocking or clicking noise.

Probable Causes:

Before delving into how you can begin to fix this issue, let us have a quick look through some of the most common causes:

Condenser fan motor or blade:

Next time your refrigerator makes a knocking noise, try to listen as to where the noise is coming from. For instance, if it comes from behind or at the bottom of the refrigerator, chances are that the condenser fan motor or blade are to blame. To reach the condenser fan motor, you may have to remove the panel, which takes less than a few seconds.

After this, you can check if the blades of the fan need cleaning, if not you’re probably going to need to check the motor.

If it is the motor causing this knocking noise, this is the first indication of a faulty motor. Luckily, such motors are replaceable so you won’t need to purchase a whole new refrigerator.

Evaporator fan motor or blade:

Evaporation is one of the significant processes of refrigeration. If it is malfunctioning, you’ll hear a knocking sound when the fridge door opens. This needs the same procedure as mentioned above, ensure that the blades are dirt-free or go for a new motor.

The Compressor:

Let us clarify further that the noise coming from the behind of the refrigerator is an indication of a plethora of causes. This can be a condensing mechanism or an unbalanced compression system. With this one, it is important to seek professional help.

Refrigerant circulation:

With all these probable causes, we can’t overlook the most obvious reason. This being the result of the refrigerant, which is pretty normal. You don’t have to go for any expert help, as with the transformation from gas to liquid proceeds, Freon passes through the compressors and condensers. That is how the knocking sound occurs which does sound alarming at first.

If it isn’t excessively loud and your refrigerator shows no decline in the cooling levels, then we suggest you simply ignore this knocking sound.

Water Hammers:

Water Hammers may sound daunting but they are easy to understand. Water Hammers occur when water flowing through pipes is forced to stop or change direction. Such as when a tap is turned off or a valve from an appliance shuts. This produces a loud knocking or “hammering” sound and if left unattended can cause damage.

Consider Reading: Why is my refrigerator making a humming noise?

How to diagnose a knocking noise on a Refrigerator compressor:

Let us share with you a few tips to help you diagnose the problem for yourself.

Step 1:

First of all, you have to figure out the place knocking noise is coming from. If your refrigerator makes knocking noise from the outside or behind the panel, it is most probably the leveling issue.

Step 2:

Get a helping hand and tilt the refrigerator backward, in this way it becomes easier for you to access the front legs. See if they are uneven, if so balance them out.

Step 3:

Thirdly, place the fridge back to it’s normal position. If the knocking persists, check whether the compressor it loose and get a screwdriver to tighten the bolts.

Normal Sounds and Noises made by your refrigerator:

Not every sound is worth worrying about, here is a list of common noises you’ll hear from your refrigerator that shouldn’t concern you.

Chirping sound:

This one is the most conventional sounds to hear while opening or closing the damper door. The damper door helps in preventing the sudden jolts while you shut the fridge door. The extra coating may cause a chirping sound which is typical and needs no special attention.

Clicking sound:

A clicking sound is produced when the defrost timer switches on or off.

Gurgling sound:

A gurgling sound takes place because of the water in the drainpipe, it can occur after several instances especially after closing the door. Freon converts from the gas state into liquid and the evaporation may leave behind some water. This water accumulates in the drain pipe and produces a gurgling sound.

Knocking sound:

The primary reasons include the consistency in the refrigerant circulation cycle. It may suggest the onset of many other problems like malfunctioning compressor or the condensing mechanism, as discussed above.

Consider Reading: Signs your refrigerator needs more Freon

Frequently Asked Questions:

Q1. Why does my refrigerator make a clunking noise?

Clunking noises occur when the compressor is loose or needs some professional maintenance.

Q2. Why does my refrigerator sound like a jackhammer?

This specific problem suggests that the water valve has stopped working or there’s some leakage in the drain pipes.

Q3. How do I stop my fridge from clicking?

The clicking sound can be stopped by replacing the compressor. Most of the time, it suggests a worn-out compressor or condensing pipes.

Conclusion

Let us end this debate on a concise note; the knocking noise isn’t always concerning and would be good advise to leave it a while to check if it persists. In the majority of cased, this noise comes from the compressor region or the condensing system. Above all, balancing the front legs of the refrigerator can also be an easy fix.

After all the suggested tips, if the knocking continues, consider contacting an expert.

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.

Conclusion

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.

Miguel Mores worked for 5 years as a member of the product management team for a home appliance company in the Philippines. He started 101appliance to answer the most common customer questions that he has encountered during his time in the industry. He now works in the digital marketing field and manages a small online bookstore on the side.