What does Samsung Oven C-21 Error Code - Causes & Fix mean?

C-21 means the oven climbed past a safe temperature. A drifting temperature sensor is the usual cause, so test and replace it first.

How do I fix Samsung Oven C-21 Error Code - Causes & Fix?

Follow the step-by-step diagnosis below. The most likely fix is identified by checking power, sensor resistance, and control-board signals in order — using a multimeter and the part numbers documented in the parts reference table.

Can I keep running the equipment with 21 active?

Generally no. Faults on Appliance units are emitted when a sensor, safety, or control circuit is outside its operating envelope. Running through an active fault risks compressor, heater, or control-board damage. Diagnose and clear the fault first.

What part is most commonly replaced for Samsung Oven C-21 Error Code - Causes & Fix?

The most frequently replaced parts for Samsung Oven C-21 Error Code - Causes & Fix are listed in the Parts Reference section of this guide with OEM part numbers and typical price ranges. Check the table for direct replacements.

Is Samsung Oven C-21 Error Code - Causes & Fix a DIY repair or do I need a technician?

Sensor swaps, fan motor replacements, and condenser cleaning are typical DIY-level repairs. Anything involving refrigerant, gas, or high-voltage (>240V) work requires a licensed technician for both safety and code-compliance reasons.

Samsung Oven C-21 Error Code - Causes & Fix

Samsung Oven C-21 Error Code — What It Means

C-21 is an overheat code on Samsung ranges. The control board saw the oven cavity rise above the safe limit and shut down heating to prevent damage.

Most of the time the oven did not actually run that hot. A temperature sensor that reads low tricks the board into driving the element too hard, and the real heat then overshoots. Treat C-21 as a heat safety event and stop using the oven until it is checked.

Jump to Fix

Common Causes

Out of spec temperature sensor A sensor reading low makes the board overdrive the element until the cavity truly overheats.
Stuck heating relay A relay on the control board welded closed keeps the element powered after the board commands off.
Shorted sensor wiring A harness short feeds the board a false low reading that leads to runaway heat.
Blocked or failed cooling Poor airflow around the control area lets reported temperatures spike.
Control board fault A failed board output can leave the element energized regardless of the sensor signal.

Step-by-Step Fix

Turn the oven off and cut power at the breaker to stop any active heating.
Let the cavity cool fully before opening panels.
Pull the range and remove the back panel to reach the sensor and harness.
Test the temperature sensor with a multimeter. Look for about 1080 ohms at room temperature.
Replace the sensor if the reading is well off that value.
Inspect the bake element and relay area for signs the element stayed on, such as scorching.
If the sensor and wiring test good, have the control board checked for a stuck relay.

Parts Often Needed

Part	Notes
Samsung oven temperature sensor (probe)	Amazon \| OEM part DG32-00002B fits many Samsung ranges. Verify against your model first.
Samsung range main control board	Amazon \| Needed when a welded relay keeps the element powered.
Oven sensor wire harness	Amazon \| Replace if the leads show a short or burn damage.

When to Call a Pro

An oven that keeps heating after the board commands off is a fire risk. If the sensor tests good but the oven still overheats, stop using it and call a tech to check the relay and board before any further cooking.