Oven displays F3 and will not start a cooking program.

Safety first: Disconnect the oven from mains power before working on the door or switch wiring.

Steps to diagnose and fix:

• Check door closure: Ensure the door closes fully and evenly. Look for bent hinges or deformed door seals that prevent full closure.
• Locate door switch: The door switch is usually located behind the front frame where the door latch engages. Access it by removing the top panel or front trim.
• Inspect switch and actuator: Verify that the switch actuator is pressed when the door is closed. Adjust the latch or switch position if necessary.
• Test switch: Disconnect the switch and use a multimeter to check continuity. The switch should change state (open/closed) when pressed and released. Replace if it does not operate correctly.
• Check wiring: Inspect the wires from the switch to the main PCB for breaks or loose connectors. Repair or replace as needed.
• Control board input: If the switch and wiring are good but F3 persists, the door input circuit on the main control board may be faulty, requiring board replacement.
• Test: After repairs, reassemble, restore power, and confirm that the oven recognizes door open/closed correctly and that F3 is cleared.