Oven shows E12 and beeps, with some functions locked out.

Safety: No internal high-voltage work is needed for basic checks.

Reset and test:

• Consult the Bomann user manual for the specific model to confirm the child lock activation/deactivation sequence (often by holding a specific key for several seconds).
• Try to deactivate the lock by holding the lock symbol or a combination of keys for 3–5 seconds.
• Disconnect the oven from power for 5–10 minutes to reset the control board, then reconnect and test again.
• If the lock symbol remains and keys do not respond, the touch control panel or main control board may be faulty and require replacement.