Testing your door or window sensor is simple:
Make sure that the chime setting for your panel is turned on and loud enough for you to hear at the location of the sensor.
Slowly open and close the door or window three times in a row, listening for the chimes.
If you hear the chime every time you open the door or window, then your sensor is working. If you do not hear the chime, verify the sensor is mounted correctly.
Proper mounting criteria includes: arrows/notches are aligned, the two pieces of the sensor are within 3/4 inch of each other (thumbs width), and are flush on the same plane. If you're still having an issue, please contact Support.