This is typically caused by a mounting issue. Please check the following:
- Ensure one piece is mounted on the door or window and the other piece is mounted on the frame
- Ensure the arrows (or notches) on the transmitter and magnet are facing each other
- The space between both the transmitter (larger piece) and magnet (smaller piece) should not exceed 3/4", or a thumbs width.
- Check for any recess in the door/frame. Ensure both pieces are on the same plane
If the sensor is mounted correctly but the sensor is still showing opened, please contact Customer Support for additional troubleshooting assistance.