Although it might be normal to make certain sounds, the refrigerator making knocking noise might be disturbing at times. Certain mild sounds such as buzzing and humming might occur due to the normal operation of the fridge. However, this knocking sound is not normal and needs attention. It may come from the cooling fans or the compressor, which shows a malfunctioning component in your appliance. So it is recommended to troubleshoot and fix it as soon as possible to avoid potential damage to the other components and negatively affect your refrigerator’s performance. Here is all you need to know when your refrigerator makes banging or knocking noises and which components to check.
Always make sure to turn off the power supply and unplug your refrigerator before you attempt any troubleshooting. Make sure to handle components with care and wear necessary PPEs to avoid personal injury and potential hazards.
- 1 Evaporator Fan
- 2 Condenser Fan
- 3 Compressor
- 4 Refrigerant Circulation
- 5 Three-Way Valve and Dampers
- 6 Water Hammers
- 7 How To Diagnose A Knocking Noise On A Refrigerator Compressor?
- 8 Frequently Asked Questions
- 9 Conclusion
The function of the evaporator fan is to distribute the cold air throughout the refrigerator. So, if this is broken, the refrigerator won’t cool properly. You can determine that this is the case if you hear a knocking sound and find that the interior temperature is warmer than usual. The reason might be that the evaporator fan motor could also malfunction. If the problem is with the evaporator fan, there may be obstructions on the fan, or the fan blades might be bent and damaged. When the fan blades are out of shape, they would be hitting something, making the refrigerator tapping noise.
How to Fix a Malfunctioning Evaporator Fan?
- Since there might be ice blocking the evaporator fan, you first need to defrost the refrigerator.
- If that doesn’t solve your problem, access the evaporator fan by removing the panel of your fridge.
- Examine the evaporator fan to check whether something is caught up in the blades prevents it from spinning. If the blades are dirty, take them off and clean them well. Ensure not to submerge the evaporator fan in water since it would damage the electronic parts inside it.
- If the fan is bent and out of shape, do not bend it back into shape as it would still be unbalanced and make a banging sound. The only thing you can do in this situation is to replace the evaporator fan right away.
- If you identify that the fan motor is responsible for causing the knocking noise, you would have it replaced by a technician. They would also check for loose parts inside the evaporator fan and fix them if required.
If the refrigerator tapping noise comes from behind the refrigerator, then the reason for this might be the condenser fan. Heat is transferred from the inside of the fridge to the exterior through the transfer coils. As these coils get hot in the process, they should be cooled down, and the older models have this air-cooled by exposing the back of the appliance. The newer no frost refrigerators have the condenser coils covered and cool down by a special condenser fan.
The condenser fans get accumulated with dust and dirt while spinning, which might cause obstructions to the spinning of the blades. Sometimes, the blades might be damaged and disfigured, which would cause the refrigerator to make knocking noise.
How to Fix a Malfunctioning Condenser Fan?
- Unplug the refrigerator from power and move it out from the wall so you’ll have easy access to its backside.
- Next, access the condenser fan by removing the back panel.
- Take off the fan and remove the dust using a brush. Try to spin it around to check whether there is anything that might have caught around the fan preventing it from spinning properly.
- Do not bend the condenser fan blades back into shape if it is bent or disfigured. Instead, replace it, and also, the condenser fan motor should be replaced if it is found to be defective.
If your Refrigerator making knocking noise has no relation to either the condenser fan or the evaporator fan, then the compressor might be at fault. Since the compressor is the main component of the fridge, there would be expensive repairs if this is the case. You might even have complete replacements to be done to restore your fridge.
A possible cause for a defective compressor is a malfunctioning or loose crankshaft inside the compressor. Sometimes the compressor itself would have come loose. The best option is to get the compressor inspected by a technician to determine the exact cause of the fault.
How to Fix a Malfunctioning Compressor?
If the diagnosis shows that the problem is loose parts, then you can get it fixed inexpensively. However, if you are to replace the compressor itself, then it would be better to buy a new refrigerator since the compressors are so inexpensive. Replacement of the compressor would cost something between $200 and $500, but it would not guarantee that the problem is solved completely.
Refrigerator making knocking noise might be due to the refrigerant being circulating in its normal cycle. The refrigerant keeps the interior cool by converting from gas to liquid by absorbing the heat from the warm air inside the refrigerator. Then the refrigerant evaporates as gas and goes back into the compressor, which is constricted and pressurized. Then this pressurized gas is then pushed into the condenser coils and transformed back into a liquid. A consistent temperature is maintained inside the refrigerator by repeating this cycle.
Three-Way Valve and Dampers
Certain refrigerators have a 3-way valve and dampers that control and distribute the airflow. These valves and dampers are commonly found in most LG refrigerators and have a knocking sound common in its normal operation.
Another possible cause for the refrigerator making knocking noise or a loud banging sound from the water supply would be a water hammer. This occurs when water is forced to change direction rapidly in a high-pressure water line, also known as a hydraulic shock. For example, this might happen when the water is used to create ice cubes and dispense water or when the water is turned on or off, like when the washer is being filled. Water hammers could damage the components and result in leaks and other repairs.
How To Diagnose A Knocking Noise On A Refrigerator Compressor?
Follow these tips to diagnose the problem yourself.
- STEP 1: Figure out the area on your refrigerator from where the knocking noise is coming from. If the refrigerator’s knocking noise comes from the outside or behind the panel, then the problem is probably a leveling issue.
- STEP 2: Tilt the refrigerator backward with the help of someone. This would make it easy for you to access the front legs. If you see that the front legs are uneven, balance them by adjusting.
- STEP 3: Place the fridge back in its normal position and check for the sound. If the knocking sound continues, check whether the compressor is loose and tighten its bolts with a screwdriver.
Frequently Asked Questions
Why does my refrigerator make a clunking noise?
Clunking noises occur when the compressor is loose, and you would need professional maintenance to repair this.
Why does my refrigerator sound like a jackhammer?
This might be due to a malfunction of the water valve or a leakage in the drain pipes.
How do I stop my fridge from clicking?
The refrigerator clicking noise might be due to a worn-out compressor or condensing pipes. This can be overcome by replacing the compressor.
Why does my fridge make noise at night?
You might have heard a series of loud noises such as pops and cracks coming out of the refrigerator at night. It has been found that the noises occur due to the contraction and expansion of the fridge components and panels as they change temperature.
How to troubleshoot Whirlpool refrigerator making knocking noise?
If the sound is coming from the compressor, loosen the bolts and slightly change the level of the compressor. The problem is internal to the compressor due to a weak mounting spring of the motor inside. Changing the level would lean more weight on the other springs, and the sound can be eliminated. Otherwise, the only repair is to replace the compressor, which might be quite expensive.
The primary reason behind the fridge making knocking noise is due to the consistency in the refrigerant circulation cycle. Malfunctioning of compressor or the condensing mechanism can also be major causes of this. If you hear a refrigerator clicking noise, it is most likely due to the switching on and off of the defrost timer. The best remedy to try out when encountering this problem is to check and adjust its legs and level them properly. However, if the refrigerator tapping noise continues, you should investigate the relevant components and get support from an experienced technician to overcome it.