Oven heats but temperature is inaccurate; food is undercooked or overcooked without any error code.

Safety first: Allow the oven to cool before removing panels or touching internal parts.

• Measure actual temperature: Place an accurate oven thermometer in the center of the cavity. Preheat to a known temperature (e.g., 180°C) and compare the reading.
• Adjust calibration: If your De Dietrich model supports temperature offset, enter the settings menu and adjust the calibration to match the thermometer.
• Inspect sensor and seal: Check the temperature sensor for secure mounting and the door gasket for leaks. Replace the sensor or gasket if defective.
• Check fan operation: Ensure the convection fan runs properly in fan modes to avoid hot or cold spots.