Wireless sensors offer great flexibility and speed when installing a security system. They are great until they fall off. In commercial installations we always screw the sensor and magnet in place. In homes that is not always practicable or desirable. Double back tape works well but under certain conditions it fails. The surface adhering too must be clean, dry and not to hot or cold.
It is always advisable to place the sensor on the non-moving part. A slamming door can cause issues with a sensor over time. Windows don’t slam but we always try to place sensors on the fixed part and the magnet on the moving part.
You should always place a sensor and magnet in the vertical position. In a horizontal position, as in over a door, it can allow the sensor to roll off the door jam or wall. The top will come loose first and slowly roll over and fall off.
To further reduce the chance of sensor or magnet falling off, I always use clear silicone in a tight bead on the outer edges. A small bead and smoothing with a finger or paper towel leaves a clean seal that will last a long time. If your sensor has a fixed base and removable top part, make sure you only secure the base.
Verify Sensor Clearance
A very common mistake made by even professional installers is placing the sensor or magnet to close to the edge of a door. As the door opens clearance can reduce. This is often the case with exterior doors that open outward. BEFORE you remove the tape cover, hold the sensor and magnet where you plan to secure it. Open the door or window and make sure nothing hits.
Sensor Gap Test
After you have installed your sensors you should perform a gap test. A gap test is checking the point at which the sensor thinks the door or window is open. If your alarm system has a chime feature, turn it on. Slowly open the door or window until you hear the chime. If you move the door or window less than ½ and inch and the chime occurs you may need to relocate the sensor and(or) magnet.
If you live in a high wind area, make sure you close, lock the door and press gently on the outside of the door. If your sensor chimes with the door locked you might wish to reconsider your sensor installation.