Oven overheats, burns food, or temperature rises far above the set value

Safety first: Turn off power immediately if the oven overheats or emits burning smells.

• Check cavity sensor: Access the temperature sensor at the rear of the cavity. Remove and test resistance at room temperature; a very low resistance (near 0 Ω) suggests a shorted sensor. Replace if out of specification.
• Inspect sensor mounting: Ensure the sensor tip is correctly positioned in the airflow and not pushed back into insulation, which can cause incorrect readings.
• Check safety thermostat: From the top or rear of the oven, locate the safety thermostat (often a small round device with two terminals, sometimes with a manual reset button). Verify continuity when cold; if it never opens on severe overheat or is bypassed, replace it.
• Examine control board relays: Look for a relay welded closed (contacts stuck). If the oven heats even when off, or continues heating after reaching temperature, the heating relay on the PCB may be stuck. Replace the main control board.
• Functional test: After replacing faulty parts, run the oven with an oven thermometer inside and verify that the actual temperature matches the set temperature within a reasonable tolerance.