When I press the ‘Arm’ or ‘At Home Zoning Mode’ button on the keypad, the keypad plays an alert sound, and the Open Door Window Sensor LED lights up, along with a Zone number (1-3). What should I do?

This means that a door or window in that zone has been left open.

If you wish to leave the door/window(s) open then you can force arm the system by pressing Arm ka_arm/Home ka_at_home_zoning_mode button on the keypad a second time.

Otherwise please first go and close the relevent door/window(s) before continuing to arm the system by pressing the Arm ka_arm/Home ka_at_home_zoning_mode button on the keypad.