Oven display shows F12, oven lights and fan may work but heating is disabled.

Safety first: Turn off power at the breaker. This fault involves mains wiring; if you are not qualified, contact a licensed electrician or service technician.

• Check supply voltage: Verify that the oven is connected to the correct voltage (typically 230–240 V single-phase in many regions). Use a multimeter at the wall outlet or junction box.
• Inspect terminal block: Remove the rear cover to access the terminal block where the power cord or cable connects. Tighten all terminal screws and look for signs of overheating or melted insulation. Replace the terminal block if damaged.
• Examine power filter / noise suppression board: Some Asko ovens use a separate power filter board. Inspect for burned components or cracked solder joints. Replace if defective.
• Control board power section: If external wiring is correct, the internal low-voltage power supply on the main control board may have failed. Replace the main control board.