May 3, 2025

Samsung Oven Error Code C-21 – How to Fix It

Getting a C-21 error on your Samsung range or oven? This code means there’s an issue with the oven temperature sensor, which monitors the internal oven temperature during cooking and self-clean cycles.

What Does the C-21 Error Mean?

The oven is detecting a temperature that is either too high or is not responding properly to the sensor readings. Common causes include:

• Faulty oven temperature sensor (RTD)
• Broken or damaged sensor wiring
• Defective main control board (less common)

How to Fix Samsung Oven Error C-21

1. Unplug the Oven: Disconnect power at the breaker or unplug the unit to ensure safety.
2. Locate the Sensor: Open the oven door and locate the temperature sensor on the rear wall inside the cavity.
3. Inspect Wiring: Check the sensor harness and connector for loose, damaged, or burned wiring.
4. Test the Sensor: Use a multimeter to measure resistance. At room temperature, the sensor should measure ~1080 ohms. If the reading is far off, replace it.
5. Replace if Necessary: If the sensor checks out, the main control board (PCB) may need to be replaced.

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