LG Range Error Code C-31

C-31 indicates that the temperature sensor mounted on the main PCB has either shorted or is reading a resistance below 972 ohms. The fault must persist for at least 10 seconds before the code is displayed. This is a board-level fault rather than a fault with the oven's cavity temperature probe. Resolving it requires replacing the main PCB.

You should not continue using the range while C-31 is active. The error indicates the control board cannot reliably monitor its own thermal state, which means protective shutoff functions tied to board temperature may not operate correctly. Discontinue use until the PCB has been replaced.

Cycling power or performing a reset may temporarily clear the C-31 code from the display, but the error will return once the control board re-checks the sensor resistance and again detects a reading below 972 ohms. A reset does not address the underlying hardware fault. Permanent resolution requires PCB replacement.

There is no field-serviceable repair for C-31 short of replacing the PCB, because the temperature sensor is integrated directly onto the board rather than connected as a separate component. Cleaning connections or resetting the unit will not correct a confirmed sensor short. If you are comfortable sourcing and installing a compatible replacement PCB, the repair is technically straightforward for an experienced DIYer.

The primary cost is the replacement PCB, which typically runs between $150 and $350 depending on the specific model. If you hire a technician to perform the repair, expect total costs including labor to fall in the range of $250 to $500 or more. Getting a repair quote from an authorized service provider before committing is advisable, particularly for older units where part cost may approach replacement cost.