Oven shows E021, interior light may flash or not work

Safety: Disconnect power. The lamp glass can be hot and fragile.

• Replace bulb: Remove the glass cover inside the oven and unscrew the lamp. Fit a new Siemens-compatible high-temperature oven bulb of the correct wattage.
• Inspect lamp holder: Check for burning or cracking around the lamp holder. Replace the holder if damaged.
• Check wiring: Inspect the lamp wiring at the rear of the cavity for insulation damage or short circuits to the chassis.
• Control board check: If bulbs and wiring are fine but E021 persists, the lamp control triac or relay on the main board may be faulty and the board may need replacement.