Oven overheats, burning food even at low temperature settings.

Safety: Turn off power before testing components.

• Verify with thermometer: Place an oven-safe thermometer inside and compare actual temperature to the set temperature.
• Check sensor: Measure resistance of the oven temperature sensor at room temperature and at a known higher temperature (e.g., 100°C after heating). Compare with specifications.
• Inspect relays: On the relay board, check if a heater relay is stuck closed (signs of melting or discoloration).

Repair: Replace the temperature sensor if readings are incorrect. If the sensor is good, replace the relay board or main control board responsible for temperature regulation.