How to Replace a Security System Sensor on an Exterior Door

Exterior door security systems use a wireless sensor, installed on the interior side of the door, that aligns with a magnet on the door frame. When the two parts are in alignment, the circuit is closed. If the door is opened while the system is armed, and the sensor and magnet break contact, the alarm sounds. The wireless sensor transmits a signal to the security base unit, so there are no wires for a burglar to cut. Replacing a sensor takes only a few minutes using basic tools.

Things You'll Need

• Screwdriver set

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Instructions

1. • 1

     Disarm the security system using your passcode. The red "Armed" light will turn off.

   • 2

     Take out the screws holding the rectangular or square sensor to the door and remove it.

   • 3

     Place the new sensor in the same place on the door and screw it down tightly.

   • 4

     Unscrew and remove the magnet plate on the interior door frame.

   • 5

     Place the new magnet plate in position on the door frame, so it aligns with the sensor on the door. Secure the magnet plate with screws.

   • 6

     Test the system at the control panel using your passcode.