The following is from your Users Manual:
Demo Mode IMPORTANT: This feature is intended for use on the sales floor with 120 V power connection and permits the control features to be demonstrated without heating elements or burners turning on. If this feature is activated, the oven will not work.
1. Press OPTIONS until "DEMO MODE" is displayed.
2. The current setting will be displayed.
3. Press the "1" keypad to adjust the setting.
4. Press START to save the setting.
5. Press OFF to exit and display the time of day http://www.kitchenaid.com/digitalassets/KERS306BSS/Use%20and%20Care_EN.pdf