Topics:

• How to manually defrost the freezer section
• Ice or frost building up inside top area of freezer section
• Ice on the back wall of the freezer

Answer:

To Manually Defrost a Sub-Zero:

A manual defrost is completed by disabling the refrigerator or freezer section. 

• It is possible to disable the freezer or refrigerator section alone in Sub-Zero units with an electronic control panel, depending on model.
• For other units, the unit as a whole can be turned off at the control panel. 
• For dial control units, turn the control down past 1 to the "off" position.
• Refer to the product links below for model-specific defrost instructions.

Model-specific instructions:

• Classic (CL) Series Products:
  • It is not possible to disable only one section of a Classic (CL) Series product.
  • The entire unit must be turned off to defrost.
• Classic (BI) Series Manual Compartment Disable and Defrost
• Designer (IT, IC, ID) Series Manual Compartment Disable and Defrost
• 648PRO Manual Zone Disable and Defrost
• 700 Series Manual Compartment Disable and Defrost
• 600 Series units:
  • Starting with serial number 1810000: 600 Series Disable and Defrost Single Section.
  • For 600 Series units prior to serial number 1810000, it is not possible to disable a single section. The entire unit must be turned off to defrost. 
    • See also. 600 Series Disable and Defrost Single Section.
• 200, 300, and 500 Series Sub-Zero products have dial controls.
  • Refer to Turn Dial Control Off to Disable Refrigerator or Freezer for more information.

See also, Refrigerator and Freezer Temperature Settings.

General tips for defrost:

1. Remove food and place in another unit if possible.
2. Place towels on the floor of the freezer or refrigerator, or on the kitchen floor in front of the unit to catch water created during the defrost process.
3. Leave the door open during defrost. The entire defrost process could take several hours, depending on the original circumstances requiring the process.
   • Alternatively, fill a bowl with hot water and place inside the freezer with the door closed. As the hot water evaporates, it may speed up the defrosting process, but this does require frequent changing of the hot water.
4. Wait 24 hours for the unit to return to normal temperatures after correcting any of the above.

Refer to the product Use and Care Guide for further information.