Oven displays E13, and the interior lamp does not work, even though heating is normal.

Safety: Switch off the power and allow the oven to cool.

Replace/Check Lamp:

• Open the oven door and locate the lamp cover (usually glass) inside the cavity.
• Unscrew or unclip the cover and remove the lamp. Inspect the filament; if broken or blackened, replace it with a Bomann-compatible high-temperature oven bulb of the same wattage and base type.
• If the new bulb does not light, check the lamp holder for signs of burning or looseness, and inspect the wiring behind the cavity (access from the rear panel).
• If the wiring and holder are fine, the lamp control on the main control board may be defective.