Fridge Humming Loudly? – 6 Causes & Easy Fixes

Loud humming noises coming from a refrigerator can be disruptive and concerning, so I decided to write this guide that addresses the most common causes AND DIY fixes.

After reading this guide you’ll know what parts of your noisy fridge are the common culprits, how to test them and whether they can be fixed or need a replacement.

1. Cause: Malfunctioning Compressor

The compressor is a vital component of your refrigerator’s cooling system, responsible for compressing refrigerant gas and circulating it through the appliance.

A failing compressor can create a loud humming noise due to mechanical issues or overheating. Reasons for compressor malfunction may include dirty condenser coils, insufficient ventilation, or worn-out components.

Fix: Clean condenser coils and ensure proper ventilation

1. Unplug the refrigerator
2. Locate the condenser coils (typically behind a grille at the bottom front or rear of the refrigerator)
3. Remove the grille and any debris surrounding the coils
4. Use a soft brush or vacuum with a brush attachment to gently clean the coils
5. Ensure there is at least 1 inch of space between the refrigerator and the wall on all sides for proper ventilation
6. Replace the grille and plug the refrigerator back in

Fix: Assess the compressor condition before considering professional technician assistance

1. Unplug the refrigerator
2. Locate the compressor (typically found at the bottom rear of the refrigerator)
3. Inspect the compressor for visible damage or signs of overheating, such as discoloration or oil leakage
4. Check the start relay and capacitor, which are responsible for initiating the compressor’s operation: A. Remove the start relay by pulling it off the compressor terminals B. Shake the start relay gently; if you hear a rattling sound, the relay may be faulty and should be replaced C. Using a multimeter, test the capacitor for continuity; if there is no continuity, the capacitor is defective and should be replaced
5. If the start relay and capacitor appear to be in good condition, you may attempt a hard-start kit installation to temporarily resolve the issue: A. Purchase a hard-start kit compatible with your refrigerator model B. Disconnect the start relay and capacitor from the compressor C. Connect the hard-start kit to the compressor according to the manufacturer’s instructions D. Plug the refrigerator back in to test if the compressor operates without the loud humming noise
6. If the issue persists or the hard-start kit does not resolve the problem, it is advisable to call a professional technician for compressor replacement

By following these steps, you can assess the condition of your compressor, attempt basic troubleshooting, and try a temporary fix before resorting to professional assistance.

Keep in mind that the hard-start kit is a temporary solution, and a professional technician should be consulted for a more permanent fix, such as compressor replacement, if necessary.

2. Cause: Faulty Evaporator or Condenser Fan Motor

Both the evaporator and condenser fan motors play crucial roles in your refrigerator’s cooling process, circulating air through the appliance. A faulty fan motor can result in a loud humming noise due to mechanical issues or imbalanced rotation.

Fix: Replace the fan motor

1. Unplug the refrigerator
2. Locate the fan motor in question (the evaporator fan motor is typically behind a panel in the freezer compartment, while the condenser fan motor is usually near the bottom rear of the refrigerator)
3. Remove any covers or panels to access the motor
4. Disconnect the wiring harness from the motor
5. Remove the motor mounting screws and pull out the motor
6. Install the new motor, reattach the wiring harness, and secure it with the mounting screws
7. Replace the covers or panels and plug the refrigerator back in

3. Cause: Obstructed Fan Blades

Obstructed fan blades can create a loud humming noise as they struggle to rotate smoothly. Proper fan function is essential for maintaining cooling efficiency within your refrigerator.

Fix: Clear obstructions or replace damaged fan blades

1. Unplug the refrigerator
2. Locate and access the fan motor as described in the previous section
3. Inspect the fan blades for obstructions, debris, or damage
4. Remove any obstructions, clean the blades, or replace them if necessary
5. Reassemble the covers or panels and plug the refrigerator back in

4. Cause: Refrigerant Line Vibrations

Refrigerant lines carry refrigerant gas throughout your refrigerator. Vibrations in these lines can create humming noises as they transmit throughout the appliance. Increased vibrations may be due to loose mounting brackets, excessive pressure, or damaged lines.

Fix: Secure mounting brackets and check for damage

1. Unplug the refrigerator
2. Locate the refrigerant lines (usually near the compressor or along the back of the refrigerator)
3. Inspect the mounting brackets and tighten any loose connections
4. Check the lines for damage or signs of excessive pressure, such as bulging or kinking
5. If damage is found, contact a professional technician to repair or replace the lines

5. Cause: Damaged or Worn Bearings

Bearings in fan motors and compressors help ensure smooth rotation of moving parts. Damaged or worn bearings can cause a loud humming noise due to increased friction or misalignment.

Although replacing bearings can be a complex task, there are some steps you can take to mitigate the issue temporarily or diagnose the problem more accurately.

Fix: Lubricate the bearings (temporary solution)

1. Unplug the refrigerator
2. Locate the fan motor or compressor with the suspected worn bearings (the evaporator fan motor is typically behind a panel in the freezer compartment, while the condenser fan motor is usually near the bottom rear of the refrigerator)
3. Remove any covers or panels to access the motor
4. Locate the bearings within the motor (these may be visible as small metal or plastic rings around the motor shaft)
5. Apply a small amount of high-quality lubricant, such as white lithium grease or silicone lubricant, to the bearings using a syringe or a precision oiler
6. Rotate the motor shaft manually to distribute the lubricant evenly around the bearings
7. Reassemble the covers or panels and plug the refrigerator back in Note: This solution may only provide temporary relief from the humming noise. If the noise persists or worsens, consider seeking professional assistance for a more permanent fix.

Fix: Inspect and assess the severity of bearing damage

1. Unplug the refrigerator
2. Locate and access the fan motor or compressor as described above
3. Carefully inspect the bearings for visible signs of damage, such as excessive wear, corrosion, or deformation
4. If the damage appears minor, consider lubricating the bearings as outlined in the previous fix
5. If the damage appears severe or if lubrication does not resolve the issue, it is advisable to consult a professional technician for bearing replacement

By following these steps, you can attempt to diagnose the issue and apply a temporary fix. However, due to the complexity of replacing bearings, seeking professional assistance is recommended for a more permanent solution.

6. Cause: Loose Components or Panels

Loose components or panels within the refrigerator can create a humming noise as they vibrate against other parts during operation. Regular maintenance checks can help identify and address these issues before they become more serious.

Fix: Tighten or replace components as needed

1. Unplug the refrigerator
2. Inspect the interior and exterior of the refrigerator for any loose or damaged components, such as shelves, drawers, or panels
3. Use a screwdriver or wrench to tighten any loose screws, bolts, or fasteners
4. Replace any broken or damaged components by ordering new parts from the manufacturer or a reliable supplier

Conclusion

By understanding the various causes of loud humming noises in refrigerators and their corresponding fixes, you can address the issue effectively and maintain the efficiency and longevity of your appliance.

Some problems may require professional assistance, so do not hesitate to consult a technician for more complex issues or when in doubt.

Regular maintenance and timely repairs can help keep your refrigerator running smoothly and quietly for years to come.