Samsung Range Error Code C-21

C-21 on a Samsung range indicates that the oven has experienced an abnormal temperature rise, or that the oven temperature sensor circuit is open or shorted. The control board monitors oven temperature continuously and triggers this code when conditions fall outside safe operating parameters. It can also appear if the main PCB itself detects an abnormally high internal temperature.

Disconnecting power for a few minutes may temporarily clear the C-21 code, but if the underlying fault is still present, the error will return once the oven is used again. A reset is useful for confirming whether the fault is intermittent, but it is not a repair. The sensor, heating elements, relays, and wiring should all be inspected to find the root cause.

Repair costs vary depending on the failed component. An oven temperature sensor is typically a lower-cost part, with replacement parts and labor generally ranging from around $100 to $250. A main PCB replacement is more expensive, often ranging from $250 to $500 or more depending on the model and labor rates in your area. Getting a diagnosis before committing to a repair is recommended, since multiple components may need to be inspected.

No, you should not continue using the oven while the C-21 code is active. This fault can indicate an uncontrolled heating condition where the oven temperature is rising beyond safe limits. Disconnect power and keep the oven door closed until a technician has diagnosed and resolved the underlying cause.

Start by disconnecting power completely before touching any components. Measure the oven temperature sensor resistance and compare it to the expected value of approximately 1080 ohms at room temperature. Next, check the resistance of the bake, broil, and convection heating elements for continuity and shorts. Finally, inspect the DLB, broil, bake, and convection relays on the main PCB for signs of damage or welding.