Does the display of your cooker show the code N-O?

When the code N-O appears in the display, it means that the oven is in safety mode (child lock). You can deactivate the safety mode by pressing the thermostat button (the button that is used for configuring the temperature) for 5 to 10 seconds. After a few seconds, you will hear a beep and ''OFF'' will appear in the display. You can now use the oven again.