Error code reference

Sub-Zero Freezer Error Code 20

Defrost under-heat with no voltage feedback through Gray/White wire at defrost start.

SourceSub-Zero 700-3 Tall Freezer - Service Manualp. 3-24, 8-3

Diagnostic procedure

The full 20 procedure

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MyPros+ · DiagnosticsStep 1 preview

First diagnostic step

With cold evaporator (<10°F), initiate Manual Defrost, then Diagnostic Mode to observe evap temp. If temp exceeds 45°F and defrost lasts longer than 5 minutes, error is false. Otherwise check Gray/White wire continuity from defrost heater to J4-4.

SourceSub-Zero Freezer - Service Manual: Integrated (700-2) Seriesp. 3-24, 8-4

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Where this code is documented

10 manuals in the MyPros+ library document this code for Sub-Zero freezer.

Models covered by the manuals that document this code

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The full 20 procedure

Where this code is documented

Models covered by the manuals that document this code

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