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Error code reference

Sub-Zero Refrigerator Error Code 10 1 10

Zone 1 evaporator thermistor open circuit detected.

Sub-Zero codesSub-Zero refrigerator codes

Zone 1 evaporator thermistor open circuit detected.

First step from the service manual

Check ohms and verify temperature readings.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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  • Step-by-step tests with expected resistance, voltage, and continuity values
  • Wiring diagram references and connector pinouts from the OEM service manual
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What 10 1 10 means on a Sub-Zero refrigerator

Error code 10 1 10 on a Sub-Zero refrigerator indicates that the control board has detected an open circuit condition in the Zone 1 evaporator thermistor. The evaporator thermistor is a negative temperature coefficient (NTC) resistor that changes its resistance value in response to temperature. The control board monitors this resistance continuously to determine evaporator coil temperature and regulate the refrigeration cycle accordingly. An open circuit means the board is receiving no signal from the thermistor, which typically corresponds to an infinitely high resistance reading outside the expected operating range.

The Zone 1 evaporator thermistor is positioned on or near the evaporator coil in the primary refrigeration compartment. When this sensor fails to report a valid reading, the unit cannot accurately manage defrost cycles or compressor operation for that zone. The first diagnostic step is to check the thermistor's resistance with a multimeter and compare the reading against the expected value at the measured ambient temperature. A functioning NTC thermistor will show a finite, temperature-dependent resistance, while a failed open-circuit thermistor will read OL or infinite resistance.

Common root causes include a physically broken thermistor, damaged or corroded wiring in the sensor harness, or a loose connector at either the thermistor end or the control board header. In some cases, moisture intrusion into the connector can cause intermittent open circuit faults. If wiring and connectors check out, the thermistor itself will need to be tested at a known temperature to confirm whether the sensor element has failed internally.

Source: manufacturer service documentation.

Common causes of 10 1 10

  1. 01

    Failed evaporator thermistor

    Part replacement

    The thermistor's internal sensing element can break or degrade over time, causing the resistance to read as infinite (open circuit). Testing with a multimeter at a known temperature will confirm this if the reading shows OL rather than a finite resistance value.

  2. 02

    Broken or damaged wiring harness

    Part replacement

    The wires connecting the thermistor to the control board can crack, fray, or break, especially at points where they flex or pass through cabinet panels. Visually inspect the harness for cuts, pinch points, or corrosion and use a multimeter to check for continuity through each wire.

  3. 03

    Loose or corroded connector

    Wiring / connection

    The connector joining the thermistor lead to the main wiring harness can back out or corrode over time, interrupting the circuit. Disconnect and reseat the connector, inspecting the terminals for oxidation or bent pins.

  4. 04

    Moisture intrusion at connector or sensor

    Wiring / connection

    Water or ice buildup near the evaporator can infiltrate the thermistor connector and cause intermittent or permanent open circuit faults. Check for signs of moisture, corrosion, or ice accumulation at the sensor mounting location and connector body.

  5. 05

    Control board failure

    Part replacement

    In rare cases, the input circuit on the control board that reads the thermistor signal can fail, causing the board to report an open circuit even when the thermistor and wiring are intact. This should only be considered after the thermistor and all wiring have been confirmed good.

See the test procedure for each cause

Frequently asked questions about 10 1 10

What does 10 1 10 mean on a Sub-Zero refrigerator?
Error code 10 1 10 means the control board has detected an open circuit in the Zone 1 evaporator thermistor. This thermistor monitors the temperature of the evaporator coil in the primary refrigeration zone. An open circuit means the board is receiving no readable resistance signal from the sensor, which prevents accurate temperature management in that zone. The issue can stem from a failed sensor, broken wiring, or a loose connector.
Can I fix error code 10 1 10 myself on a Sub-Zero refrigerator?
Some steps, such as reseating a loose connector or inspecting visible wiring for damage, can be performed by a knowledgeable DIYer. However, accurately diagnosing this code requires a multimeter to check thermistor resistance and wire continuity, and accessing the evaporator thermistor may require partial disassembly of interior panels. If the thermistor or wiring needs to be replaced, a technician familiar with Sub-Zero units is recommended to ensure correct component selection and reassembly.
Is it safe to keep using my Sub-Zero refrigerator when error code 10 1 10 is active?
When the evaporator thermistor is in an open circuit state, the refrigerator cannot accurately monitor or control the cooling cycle in Zone 1, which can lead to improper temperatures and potential food spoilage. It is advisable to check and record the actual compartment temperature and avoid storing temperature-sensitive items until the fault is resolved. Continued operation without repair could also affect defrost cycle management and lead to secondary issues.
How much does it cost to repair error code 10 1 10 on a Sub-Zero refrigerator?
Repair costs vary depending on what has failed. If the fix is simply reseating a connector, the cost may be limited to a service call fee, which typically ranges from $100 to $200. Replacing a thermistor sensor is generally a lower-cost repair, with parts and labor often falling in the $150 to $350 range. If the control board is the root cause, total costs including parts and labor can range from $400 to $800 or more depending on the specific unit.
Will resetting my Sub-Zero refrigerator clear error code 10 1 10?
A reset may temporarily clear the error code from the display, but if the underlying hardware fault in the thermistor circuit has not been corrected, the code will return once the control board re-runs its diagnostics. Resetting is not a repair and should only be used as part of the diagnostic process, for example to confirm whether the fault is intermittent or persistent. The thermistor, wiring, and connectors should be tested and repaired before considering the issue resolved.

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