Topics:

• Does a Sub-Zero unit have to be manually defrosted?
• When does a Sub-Zero unit defrost?
• Is there an automatic defrost feature on a Sub-Zero?

Answer:

Sub-Zero refrigerator and freezer sections have an automatic defrost feature and should not require manual defrosting under normal operating conditions.

• If needed, refer to Manually Defrost a Sub-Zero for more information.

• 600, 700, Classic Series (BI), Designer Series (IT, IC, ID), UC Undercounter, and 648PRO units:
  • Freezer section is controlled by an energy-saving adaptive defrost system and defrosts as needed.
  • Refrigerator section will defrost during each off cycle of the refrigerator compressor.
• 200/300 and 500 Series units:
  • Freezer section automatically defrosted based off compressor runtime.
  • Depending upon model, compressor runtime ranged from 6 hours 21 minutes, 12 hours, or 24 hours.
  • Refrigerator section did not have an automatic defrost feature. Defrosting should not be required under normal operation.
• For units with electronic controls, the temperature change during defrost will not show as a rise in temperature on the display since it only provides an average temperature over time.

• Turn Off One Section of a Sub-Zero Refrigerator
• Sub-Zero Warm Refrigerator Troubleshooting
• Sub-Zero Warm Freezer Troubleshooting