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Error code reference
Sub-Zero Refrigerator Error Code 20 4 50
Defrost heater has failed open.
SourceSub-Zero IW-30CI Wine Refrigerator - Full Service Manualp. 54
Diagnostic procedure
The full 20 4 50 procedure
Step 1 is visible so you can confirm you are on the right page. The remaining steps, the ones that tell you whether to actually replace a part, unlock with any pass.
MyPros+ · DiagnosticsStep 1 preview
1
First diagnostic step
Ohm the defrost heater.
SourceSub-Zero IW-30CI Wine Refrigerator - Full Service Manualp. 54
More steps, wiring diagram references, and verified part numbers
Includes expected resistance and voltage values, connector pinouts, and supersession notes for replacement parts.
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Where this code is documented
9 manuals in the MyPros+ library document this code for Sub-Zero refrigerator.
Models covered by the manuals that document this code
- BI-36F
- BI-36R
- BI-36S
- BI-36U
- BI-42S
- BI-42SD/O
- BI-42SD/S
- BI-42SD/S/CH
- BI-42SD/S/PH
- BI-42SD/S/TH
- BI-48S/O
- BI-48S/S
- BI-48S/S/CH
- BI-48S/S/PH
- BI-48S/S/TH
- BI-48SD
- IC-24C(I)
- ICBBI-30U/O-LH
- ICBBI-30U/O-RH
- ICBBI-30U/S/PH-LH
- ICBBI-30U/S/PH-RH
- ICBBI-30U/S/TH-LH
- ICBBI-30U/S/TH-RH
- ICBBI-30UG/O-LH
More models are covered than are listed here.
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