Safety first: Disconnect mains power and allow the oven to cool before working on it.

Steps to diagnose:

Check with thermometer: Use an oven thermometer to confirm that the actual temperature is significantly higher than the set temperature.
Test temperature sensor: Access the cavity sensor and measure its resistance at room temperature and at a known elevated temperature (if possible). Replace if readings are out of specification.
Inspect sensor wiring: Look for shorts to chassis or between sensor leads. Repair or replace damaged wiring.
Control board relays: Inspect the main PCB for a relay stuck closed. If the oven continues heating when it should cycle off, replace the control board.
Recalibration (if supported): Some OBH Nordica models allow temperature offset adjustment via the user menu. Consult the manual and adjust if minor correction is needed.
Test: After repairs, run the oven at 180°C and verify that the temperature cycles correctly around the set point.

Oven overheats and burns food even when set to a moderate temperature.

Possible Causes