Is Your Refrigerator Making Knocking Noises? (Troubleshoot It)

It can be frustrating to hear knocking noises from your refrigerator, and you undoubtedly want to find the reason behind the unpleasant sounds. While refrigerators have their humming noises daily during regular operation, it can be alarming to hear something new.

Refrigerators make knocking noises because of condenser fan problems, issues with the compressor, and occasionally an ice maker jam. In addition, your evaporator may be bad, or there may be an issue with the refrigerant circulation.

Sometimes you can fix the problem yourself, but you’ll also want to call a professional to help address the issue. While you don’t need to jump on the phone with customer service immediately, you must address the issue so it doesn’t lead to additional problems.

We will look at what is causing a knocking sound in your LG refrigerator and what familiar sounds you should hear from your fridge.

What is Causing a Knocking Sound in My LG Refrigerator?

We have outlined the seven leading causes behind a knocking sound in your LG refrigerator. As with most issues, you usually have to look at various parts of your fridge to determine the exact cause.

If one troubleshooting solution doesn’t solve your knocking sound, it’s best to move on to the next one. Often, it would be best to try several things before you discover the root cause of your problem.

1.   Condenser Fan Problems

One of the most common reasons you hear a knocking sound on your LG refrigerator is a problem with your condenser fan. If you notice the sound coming from the back of your fridge, it’s likely due to a faulty condenser fan.

The condenser fan is responsible for cooling the condenser coils, and if there is an issue causing them to overheat, your fridge cannot cool. In addition, a faulty condenser fan can cause knocking noises if it hits something, like ice, in the back of your refrigerator.

You want to inspect the back of your refrigerator to check for signs of damage, obstruction or if it is frozen. If you don’t find any snags or issues, move on to the next step.

2.   Evaporator is Bad

If your evaporator is bad, it can’t evenly distribute air throughout your refrigerator. When this occurs, your evaporator fan might begin making knocking noises. You can determine whether the evaporator is faulty by checking if the temperature in your fridge is warm and not properly cooling.

Here are the steps to checking your evaporator fan:

  1. Let your fridge defrost by unplugging it from the wall
  2. Once it is defrosted, plug it back in and see if you still hear the knocking sounds
  3. If defrosting didn’t resolve the issue, remove the cover from your evaporator fan and ensure it is clean
  4. Next, rotate the fan to determine whether anything, like ice build-up, is obstructing it and preventing it from operating correctly
  5. If you notice any obstructions, remove them and check whether noises are still coming from the refrigerator
  6. If no obstructions are found, you should disconnect the evaporator fan and test for continuity with a multimeter
  7. If the unit shows continuity and is still making a knocking sound, you should move on to the next step. However, if no continuity is found, you will need to replace the evaporator fan
  8. After you replace the fan, ensure the knocking sound is eliminated

 3. Problems With The Compressor

The compressor is vital to the proper operation of your refrigerator because it distributes refrigerant throughout your fridge. For example, a faulty compressor can cause knocking sounds within your refrigerator.

You should unplug your refrigerator, find the compressor on the back of your fridge, and look for loose parts. If there is an issue with the compressor, you’ll want to contact a service tech to aid in replacement.

However, compressors are expensive, and you might find it worth replacing your refrigerator if you are confident the problem is with the compressor.

4. Refrigerant Circulation

Refrigerant circulation is one of the most basic reasons you hear a knocking sound in your refrigerator. As the gas turns into a liquid, Freon must pass through the condensers and compressors in your fridge.

A knocking sound due to refrigerant circulation is normal and isn’t a call for concern. However, if you can’t live with the sound, you can contact a tech to inspect the problem further.

5. Water Hammers Could Be The Issue

If water flows through the pipes and is forced to switch direction, you experience water hammers. You want to ensure this isn’t what is causing the knocking sound, as it can lead to damage.

In addition, water hammers occur when the water valve opens and closes due to the high pressure sent to your refrigerator. You may also hear the knocking sound when using the dispenser for water or ice.

Sometimes if the water is shut on or off, you will hear a knocking sound, like when your washer fills up. However, you should note when the knocking occurs, and if it doesn’t coincide with the use of another appliance, water hammers are not your problem.

If you’ve determined water hammers cause the issue, you will want to contact a professional to help with the problem. For example, a plumber can install a water hammer arrestor in your pipes where the sound originates.

6. Ice Maker Jam

If you are still trying to determine the cause of knocking noises in your refrigerator, it might be due to your ice maker. While the ice maker will make a noise as it’s filling, you may experience a louder knocking noise if there is a jam.

Turn off your refrigerator and clean the blockage to fix an ice maker jam. You will likely experience an ice maker jam if there are hard water mineral deposits, frozen water, or dirt.

If you plan on thawing out your freezer, ensure you have towels on the floors to help absorb excess water.

7. Fridge Plastic Parts

Your fridge’s plastic parts can make knocking noises due to thermal expansion; despite the alarming sound, it is normal. So, while you set your fridge at an exact temperature, it fluctuates during the day, and during thermal expansion, the parts change sizes as they warm up.

As the parts expand, you’ll hear a popping or knocking sound, especially during defrosting. In addition, fridges vibrate throughout the day, which can also cause plastic parts to make unusual noises.

You may experience a knocking sound in your fridge’s plastic parts regardless of age, as it’s a part of the operation process. You should inspect the interior and ensure all shelves and drawers are correctly in place to reduce the chance of knocking noises.

What are the Normal Sounds Made By Your Refrigerator

There are various reasons why your refrigerator makes noise, including obstruction or an issue with your compressor or evaporator fan. There are several normal noises, like clicking or gurgling, but you should investigate further if it’s a new noise.

While unusual sounds from your refrigerator can be alarming, it’s always good to know which are normal sounds. So here’s a look at the top sounds you may hear from your fridge that doesn’t require maintenance or repair.

However, if you are ever concerned about a sound coming from your fridge, don’t hesitate to investigate further or contact a professional to address the matter.

Why does my refrigerator sound like a jackhammer?

If your refrigerator sounds like a jackhammer, it’s likely because of a water valve malfunction or a drain pipe leak. You might also hear the jackhammer sound when you first turn on or off the water.

Chirping Sound

You shouldn’t worry about a bird in your fridge; instead, you might hear a chirping sound if there is an issue with your evaporator fan. However, it’s also normal to hear a chirping sound when the damper door opens and closes. You may also hear a strange sound after dispensing water; however, it should stop after seven seconds.

Clicking Sound

A clicking sound in your refrigerator could be caused by a broken connection resulting in the ice maker not operating correctly. However, you may also hear a clicking sound when the defroster timer turns on and off. A click is often heard on a fridge when the temperature control unit turns on and off or after a power outage.

How do I stop my fridge from clicking?

If you hear a clicking sound from your fridge, it’s probably due to worn-out condensing or compressor pipes. Therefore, a replacement of your compressor should fix this issue.

Gurgling Sound

It is normal to hear a gurgling sound from your refrigerator when the evaporator cools a boiling gas. This process is how your refrigerator is cooled, so it is entirely normal if you hear a gurgling sound. Occasionally, you’ll hear a gurgling sound when you close the fridge door because water is in the drain trap area.

Knocking Sound (sometimes)

A knocking sound is sometimes typical, mainly due to refrigeration circulation. If you typically hear the sound at specific times, you likely won’t have an emergent issue. However, if the noise is new and doesn’t go away with maintenance, you should further investigate the problem.

How To Diagnose A Knocking Noise On A Refrigerator Compressor

To properly diagnose a knocking noise on a refrigerator compressor, you want to follow these steps:

  1. Determine the area of your fridge where the knocking noise is coming from, and if the issue is on the outside, you likely have a leveling problem
  2. With the help of a partner, lean the fridge back and see whether the front legs are level or require adjustment
  3. Place your refrigerator back in its correct spot and listen for the knocking noise. If you still hear the knocking noise, you want to ensure the compressor isn’t loose and tighten any loose bolts
  4. Remove the evaporator fan and check for debris or stuck ice. If your fan is damaged, it requires replacement.
  5. Check the back of the fridge, locate the compressor, and inspect it for damage. You may have to remove a grate or back cover to access the compressor and ensure it is properly tightened.
  6. Check the cooling fan for damage or obstructions. Also, if the fan is loose, you should tighten it or replace it if damaged.

This YouTube video offers an animated tutorial on diagnosing a knocking noise on a refrigerator.

Frequently Asked Questions

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

You can put a pot of boiling water in your fridge to help speed up the deicing process. The steam created from the hot water will help thaw the ice. You want to put the pot on a towel to help absorb the water as it melts and repeat the process every 30 minutes until your fridge is defrosted.

Can You Defrost A Freezer Without Turning It Off?

You can defrost a freezer without turning it off and start by moving all the items into the refrigerator. Next, place a pot of boiling water inside the freezer and use an ice scraper to help remove excess ice. Remember to place towels on the floor in front of your freezer to help soak up the water.

How Do I Stop My Ice Maker From Making Noise?

You always want to ensure there is no build-up in your freezer, which can cause noises from your ice maker. You also want to inspect the fan motors and drain line for damage or obstruction.


If your refrigerator makes knocking noises, you probably have an issue with your evaporator or condenser fan. Other times, the knocking noise is normal and caused by refrigerant circulation. You always want to inspect the interior and exterior of your refrigerator for obstructions or damage, including ice. Ensuring your refrigerator is properly operating will help extend its life and offer a suitable place to keep your food.