LG Range Error Code C-20

The C-20 code on an LG range means the control board has detected that the oven temperature sensor is operating outside its acceptable resistance range. A properly working sensor reads around 1090 ohms at room temperature. If resistance climbs above 2850 ohms, the sensor circuit is open. If it drops below 830 ohms, the circuit is shorted. Either condition prevents accurate temperature control and triggers this fault.

No, you should not attempt to use the oven while C-20 is active. The error means the control board cannot accurately monitor oven temperature, which removes a critical safety safeguard against overheating. Disconnect power and have the sensor or wiring inspected before operating the range again.

If only the oven temperature sensor needs replacement, parts typically run in the range of $20 to $60 depending on the specific model, and a repair technician may charge $100 to $200 in total including labor. If the main PCB is at fault, parts alone can range from $150 to $300 or more, with labor added on top. Diagnosing the fault accurately before ordering parts will keep costs as low as possible.

A knowledgeable DIYer can diagnose and often fix C-20 by disconnecting power, opening the back cover, and measuring the sensor resistance at connector CN320 on the main PCB. If the reading is outside the 830 to 2850 ohm range, the sensor or its wiring needs replacement. Replacing an oven temperature sensor is a straightforward repair involving unplugging the harness and removing a few screws, but working inside the appliance does require comfort with basic electrical testing.

Resetting power by unplugging the range or switching off the circuit breaker may temporarily clear the display, but the code will return as soon as the oven attempts to operate if the underlying sensor or wiring fault is still present. A permanent fix requires diagnosing and correcting the out-of-range resistance condition in the sensor circuit.