The oven heats but cannot reach the set temperature; food is undercooked, and the temperature seems too low.

Safety first: Disconnect power before testing components.

• Verify with thermometer: Place an oven-safe thermometer in the center of the cavity and compare the actual temperature to the set temperature.
• Check elements: Visually inspect elements while heating; they should glow evenly. Dark spots or an uneven glow indicate a failing element. Test resistance and replace any suspect element.
• Sensor check: Test the NTC sensor resistance at room temperature and at a known elevated temperature (e.g., 100°C in hot water, if removable). Replace it if readings are inconsistent with specifications.
• Control calibration: Some Clatronic models allow temperature offset adjustment in the settings. Refer to the manual to recalibrate if the oven is consistently off by a fixed amount.