Neff oven shows E021 and the child lock or key symbol may be displayed

Safety first: No internal live work is required for basic checks, but disconnect power before removing panels.

• Disable child lock: Follow the user manual to deactivate the child lock (often by holding a specific key combination for several seconds). If E021 remains, continue.
• Clean control panel: Wipe the touch area with a slightly damp cloth and dry thoroughly. Grease or moisture can cause false key presses.
• Power cycle: Turn off power for 10 minutes, then restore and test.
• Inspect UI board: If the error persists, remove the control panel and inspect the user interface PCB for damage or corrosion.

If cleaning and resetting do not clear E021, the user interface board may need replacement.