ERROR CODE EXPLAINED
Sub Zero 600 Series Refrigerator
Sub Zero 600 Series Refrigerator EC 21 Error Code
What it means
The freezer defrost system detected an overheat condition.
Try this first
- If temperatures are high, contact service.
- If temperatures are near normal, clean the condenser.
- Press and hold the door-ajar alarm key for about 15 seconds to clear the code if your model has that key.
- If the error returns or temperatures rise, contact service.
Can I keep using it?🔴 Defrost overheat
Repair usually required?⚠ Service may be required
If the error keeps returning
If the condition returns after troubleshooting, qualified service may be required.
Official source
Troubleshooting information verified against manufacturer support documentation.
View manufacturer support page →Safety note:ApplianceSignal provides general troubleshooting information. Always follow the appliance manufacturer's safety instructions and disconnect power when required.