Sub-Zero Ice Maker Error Code Rapid flashing light

A rapidly flashing control board indicator light means the ice maker has detected an over-temperature condition, with internal temperatures reaching or exceeding 170°F (77°C). The unit shuts down automatically to protect itself from heat damage. The fault points to either a genuine overheating problem in the refrigeration or airflow system, or a failed liquid line thermistor that is reporting a false high-temperature reading.

No. The rapid flash indicates the unit has already shut down due to an over-temperature condition, so it will not produce ice in this state. Attempting to force the unit to operate without addressing the root cause risks damage to the compressor and other refrigeration components. The unit should remain off until the overheating source is identified and corrected.

Repair costs vary depending on the cause. A condenser cleaning is typically the least expensive service, often in the range of $75 to $200 for a service call. Replacing a liquid line thermistor generally costs between $150 and $400 including parts and labor. If the issue involves a refrigerant recharge or refrigeration system repair, costs can range from $300 to $700 or more depending on the extent of the problem and local labor rates.

Start by checking that the ambient temperature in the installation space is within Sub-Zero's specified operating range. Inspect and clean the condenser coil, and confirm the condenser fan is operating. If environmental conditions are acceptable, test the liquid line thermistor resistance and compare it to the expected value for the current temperature. If the thermistor is out of spec, replace it. If the coil is clean and the thermistor tests correctly, a refrigerant or refrigeration system issue may require a certified technician.

A reset may temporarily clear the fault indicator, but the light will return rapidly if the underlying cause has not been resolved. If the unit overheats again after a reset, the control board will shut down and flash again. Clearing the code without fixing the root cause, whether it is a dirty condenser, an out-of-range ambient temperature, or a bad thermistor, will not result in normal, sustained operation.