Zone Thermistor Shorted

Appliance: Sub-Zero 700 Series Models: 700TR, 700TC/I, 700TF/I, 700BR, 700BF/I

⚠ What This Means

The display shows 55 (sometimes displayed as -55-) with the corresponding zone indicator flashing. This indicates the zone thermistor in that zone has a short circuit. This can cause the compartment to run too cold as the control cannot accurately read temperature.

Caution: A shorted thermistor can cause the compartment to run excessively cold and potentially freeze food in the refrigerator zone. Address this error promptly.

🔧 How to Fix

Identify which zone indicator is flashing.
Check the wiring to the zone thermistor for damage, pinched wires, or bare wire contact.
Test thermistor resistance: should read approximately 32,500 ohms at 32°F and 10,000 ohms at 77°F.
If resistance reads near zero or very low, the thermistor is shorted — replace it.
After replacement, turn the unit OFF at the master power switch for 10 seconds.
Turn the unit back ON to clear the error mode.

Test Specifications
Thermistor at 32°F (0°C): ~32,500 ohms
Thermistor at 77°F (25°C): ~10,000 ohms

🛒 Replacement Parts for This Fix

Zone Thermistor ~32,500 ohms at 32°F

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❓ Frequently Asked Questions

What does error 55 mean on Sub-Zero 700?

Error 55 or -55- means the zone thermistor has a short circuit. The zone indicator that flashes tells you which zone is affected.

Can a shorted thermistor damage my Sub-Zero?

A shorted thermistor causes the control to misread temperature, potentially running the compartment too cold. It won't damage the unit but may freeze food.