LG Oven Error Code C-20

The C-20 code on an LG oven means the oven temperature sensor circuit is open or shorted while the oven is running. The control board cannot receive a valid temperature reading from the sensor probe inside the oven cavity. This prevents the oven from regulating heat properly and triggers the error to alert you to a sensor circuit fault.

You should not continue using the oven while C-20 is active. The error means the oven cannot accurately monitor its internal temperature, which creates a risk of overheating or unpredictable cooking results. Stop using the oven until the sensor circuit fault has been diagnosed and repaired.

If only the oven temperature sensor needs to be replaced, parts typically range from around $20 to $60 depending on the model, with additional labor costs if a technician performs the repair. If the main PCB is at fault, parts alone can range from $100 to $300 or more, making professional diagnosis worthwhile before committing to that repair.

Some causes of C-20 are DIY-friendly. Checking and reseating the sensor connector at the main PCB requires no tools and no parts. Testing the sensor probe with a multimeter and replacing it if faulty is also a manageable repair for someone comfortable working with appliances. If the fault points to the main PCB or extensive wiring damage, a qualified technician is recommended.

A reset, such as powering the oven off at the circuit breaker for a few minutes, may temporarily clear the C-20 code. However, if the underlying fault in the sensor or its wiring still exists, the code will return as soon as the oven attempts to operate again. A reset alone is not a repair and should only be used as a step in diagnosis.