Sub-Zero Refrigerator Error Code 01: Thermistor Fault... | appliancefaults.com

Technical Background:

Error Code 01 on a Sub-Zero refrigerator typically indicates a problem with the refrigerator compartment thermistor. The main control unit (MCU) monitors the thermistor's resistance to determine the compartment temperature. The MCU sends a low DC voltage (typically 5V DC) through the thermistor circuit, and the voltage drop is proportional to the thermistor's resistance. If the MCU detects an abnormal voltage reading, it triggers Error Code 01.

Symptoms:

The homeowner observes that the refrigerator compartment is warmer than usual. The unit may be cycling on and off frequently, or not at all. Error Code 01 is displayed on the control panel. Food may be spoiling prematurely.

Possible Causes:

Open or shorted thermistor
Wiring harness damage to the thermistor circuit
Loose or corroded wire connections
Faulty main control board (MCU)
Thermistor out of calibration
Ice build-up on the thermistor

Solution:

1

Disconnect power to the Sub-Zero refrigerator at the breaker panel.
2

Locate the thermistor in the refrigerator compartment (usually near the evaporator).
3

Using a multimeter, measure the resistance of the thermistor. Refer to the Sub-Zero service manual for the correct resistance value at the measured temperature.
4

Inspect the wiring harness and connectors for any signs of damage or corrosion. Repair or replace as needed. Use a wire stripper and crimping tool for repairs.
5

If the wiring is good and the thermistor resistance is incorrect, replace the thermistor with a new, OEM Sub-Zero part.
6

If the thermistor and wiring are good, suspect a faulty main control board. Replacement of the MCU may be necessary.
7

Reconnect power to the refrigerator and verify the Error Code is cleared.

Safety Warning:

Disconnect power to the refrigerator at the breaker panel before performing any repairs. Lock Out/Tag Out (LOTO) procedures should be followed to prevent accidental re-energization. Some components may retain a high voltage charge even after power is disconnected. Exercise caution when working around electrical components.

Prevention:

Regularly check the refrigerator compartment for ice build-up, especially around the evaporator and thermistor area. Ensure proper door seals to prevent excessive moisture from entering the compartment. Avoid overloading the refrigerator, which can restrict airflow and affect temperature regulation. Clean the condenser coils at least every six months.

Expert Tip:

Sub-Zero refrigerators have a service mode that allows you to test individual components and clear error codes. Consult the service manual for the specific sequence to enter service mode on your model. Use caution; incorrect inputs can cause damage to the unit.

Frequently Asked Questions

•Where can I find the service manual for my Sub-Zero model?

You can often find service manuals online from various appliance parts retailers or directly from Sub-Zero's website. Make sure to have your model number handy when searching.

•What is the typical resistance range for a Sub-Zero refrigerator thermistor at 70 degrees Fahrenheit?

While it varies by model, most Sub-Zero refrigerator thermistors read between 5,000 and 10,000 ohms at 70 degrees Fahrenheit. Refer to your model's service manual for the specific value.

•How do I clear the error code 01 after replacing the thermistor?

Some Sub-Zero models clear the error code automatically after the faulty component is replaced. However, other models require you to manually clear the code through the control panel or within the service mode. Consult the service manual for the specific procedure for your model.

Sub-Zero Refrigerator Error Code 01: Thermistor Fault Troubleshooting

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•Where can I find the service manual for my Sub-Zero model?

•What is the typical resistance range for a Sub-Zero refrigerator thermistor at 70 degrees Fahrenheit?

•How do I clear the error code 01 after replacing the thermistor?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: