Microwave displays E18 and emits a continuous beep; door may not unlock on some models with child lock.

Safety first: If the door is locked and food is inside, unplug the microwave and allow it to cool before attempting to open.

• Disable child lock: On most Telefunken models, press and hold the STOP/CANCEL or a dedicated lock key for 3–5 seconds until the lock icon disappears. Refer to the user manual for the exact sequence.
• Power reset: Unplug the unit for 5–10 minutes to clear any temporary logic error, then plug back in.
• Check keypad for stuck keys: Inspect the lock button area for physical sticking. If stuck, the membrane keypad may need replacement.
• Control board replacement: If E18 persists and the lock cannot be toggled, the control board may be defective and should be replaced.