Topics:

• Humming, vibrating, singing, crackling, knocking, or sizzling noise from freezer, refrigerator, or Wine Storage
• Is humming, vibration, or grinding a normal operating sound?
• Is it safe to operate the unit if humming?
• Buzzing noise stops when drawer or door is opened or knocking noise stops after a door or drawer is closed
• How to determine which fan motor is causing noise
• Glowing red inside freezer section

Cause:

• Fan blade or fan motor not working properly
• Ice build-up on the fan inside the freezer
• Obstruction due to over-filling the unit
• Normal operation

Troubleshooting:

These steps assume a standard refrigerator and freezer combination unit.

• Adjust troubleshooting accordingly for all refrigerator, all freezer, or Wine Storage units.
• Freezers go through normal defrost cycles, and moisture on or near a defrost heater can cause a sizzling or crackling noise.

First, determine if the noise is related to a fan motor:

1. Open all doors to determine if the noise stops.
   • If the noise stops with all doors open, continue to step 2.
   • If the noise continues with all doors open, close the doors and skip to the next section for issues not related to a fan motor.
2. Close only the refrigerator section door (or upper door on a Wine Storage unit) to see if the noise returns.
   • If it does, and the unit has an Air Purification System, verify the noise is not from the air filter fan.
   • Refer to Air Purification System Fan Noise for troubleshooting and more information.
   • If the Air Purification System is not the source of the noise, or the unit does not have an Air Purification System, then the noise is related to the refrigerator evaporator fan motor. Contact Factory Certified Service.
3. Open the refrigerator door again.
4. Close only the freezer section door (or drawer in a Wine Storage unit) to see if the noise returns.
   • If it returns, the noise is related to the freezer evaporator fan motor. Contact Factory Certified Service.
   • The freezer fan is usually not visible, but ice may be.
5. Close the doors after testing.

If the noise is not related to a fan motor:

1. If the product has not been cleaned in the last 6 to 12 months, Clean the Condenser.
2. If ice build-up is visible, defrost the section. In some models, it is possible to disable the freezer section for a manual defrost.
3. Make sure food packaging is not pushed into the refrigerator or freezer fan.
4. If any burning odor or other unusual symptoms accompany this noise, contact Factory Certified Service.
5. If the refrigerator or freezer still makes abnormal noises after the troubleshooting steps are complete, no further troubleshooting advice is available. Contact Factory Certified Service to schedule an appointment for repair.

For other noises, see:

• Sub-Zero Beeping
• Sub-Zero Grille Vibration
• Sub-Zero Gurgling or Hissing
• Sub-Zero Noisy Door Hinge
• Noise from Compressor Area for banging, buzzing, clicking, or humming noises.

Additional resources:

• Condenser Fan Motor Operation
• Sub-Zero Ice Bin Installation
  
• Manually Defrost a Sub-Zero
• Red Glow in Freezer

Disable a refrigerator or freezer zone:

• 600 Series Disable Single Section Starting with Serial # 1810000
• 700 Series Manual Zone Disable Mode
• Classic (Formerly Built-In) Manual Compartment Disable
• Designer (Formerly Integrated) Manual Compartment Disable Mode