Door Window Contact Security Sensors

What is a Door Window Contact security sensor?

Door Window contacts are security sensors that, when programmed into your alarm panel, allow you to monitor the open close status of a door or window. These contact sensors are two part devices consisting of a sensor with internal reed switch and a magnet. When the magnet moves away from the reed switch, this sensor is triggered sending an open/close signal to the alarm panel.

Depending on programming conditions and arming status of the panel, triggering a door window contact can cause an alarm state.

Common Wireless Door Window Contact Sensors

Every wireless or hybrid compatible security system works with one or more wireless communication protocols including 319.5MHz, 345Mhz, 433MHz, and PowerG. Part numbers for a variety of the most common sensors can be found below:

2GIG 345MHz Sensors
2GIG-DW10-345 Thin Door/Window Security System Contact Sensor

DSC 433MHz Sensors
DSC WS4945 Wireless Door/Window Contact Intrusion Detector

DSC PowerG Sensors
PG9303 PowerG Wireless Door/Window Sensor

Qolsys 319.5MHz Sensors
QS1135-840 IQ Mini Door/Window Sensor

Testing a Door Window Contact for Functionality

It is best to test the contact sensor before mounting and after. Before to ensure that the sensor works correctly and communicates with the panel and after to ensure the sensor is being triggered as intended when the door or window is opened and closed. Testing the sensor is as simple as:

  1. Programming the device into the panel
  2. Placing the magnet next to the side of the sensor with the reed switch for a few seconds
  3. Then pulling the magnet away from the sensor

When programmed this should cause an open status at the alarm panel.

After testing the sensor you will want to mount it in its intended location.

Mounting a Door Window Contact

While you should always follow manufacturer guidelines when it comes to mounting specifications, most door window contacts are mounted in a similar fashion. Installation manuals for common sensors can be found below.

  1. Choose the Location: Identify where on the door or window you want to place the sensor.
    • For doors, the magnet is typically placed on the top corner of the door itself, opposite from the hinge side, but depending on the door and frame, you might choose a different location. The sensor is mounted on the frame. When the door is closed, the sensor and magnet should be in contact with one another and the magnet should be on the reed switch side of the sensor.
    • For windows, the magnet should be mounted on the frame of the moving portion of the window. The sensor on the frame. Reed switch side of the sensor should face the magnet.
  2. Prepare the Surface: Most contact sensors come with double-sided foam tape and or mounting screws. If using included foam tape, make sure the area where you will place the sensor and its magnet is clean and dry. This helps ensure the adhesive sticks properly.
  3. Mount the Sensor and Magnet: If using adhesive remove the backing on the strip and attach one part of the sensor to the door and the other part (the magnet) to the door frame. Make sure the two parts are aligned and close enough to interact when the door is closed. Ensure the gap between the sensor and magnet does not exceed the recommended magnetic gap found in the manual.
  4. Test the Sensor: After installation, test the sensor by opening and closing the door or window. Check your control panel or mobile app to ensure that it registers the open and close actions.

Installation Manuals

2GIG-DW10-345 Thin Door/Window Security System Contact Sensor
2GIG DW10-345 Installation Manual

QS1135-840 IQ Mini Door/Window Sensor
QS1135-840 Installation Manual

DSC WS4945 Wireless Door/Window Contact Intrusion Detector
WS4945 Installation Manual

PG9303 PowerG Wireless Door/Window Sensor
PG9303 Installation Manual

Common Reasons for False Triggers

  1. Sensor and magnet aren’t properly aligned.
    • Each sensor has a magnetic gap distance, the maximum distance from the sensor for the magnet to reliably hold the circuit shut. If installed near the edge of that gap the sensor can open more easily, causing false alarms.
    • Sensors typically have an arrow or other marking identifying where the reed switch is found. The magnet must be centered on that spot. Misalignment will make it easier for false alarms to occur.
  2. Build material of the Door Window is metal
    • Metal doors can affect the magnetic gap and sensor signal strength. Try reorienting the sensor and keeping the magnet a bit closer.
      3.Incorrect programming, such as zone type
    • Is this supposed to be an entry door? If you enter a door expecting a disarm countdown and the alarm goes off, check to make sure you have that zone programmed as an Entry Exit type.
    • Most panels can be armed with no entry delay as an option each time you send an arm command (or at the panel). If you accidentally selected No Entry Delay this would be reflected in the history for that arming event.
  3. Is it a temperature controlled environment?
    • If the sensor is installed in an outdoor/unregulated environment like a garage, barn, shed, etc., it should be an outdoor rated model. A standard indoor sensor will have a variety of potential false alarm/failure causes.
    • Outdoor rated door window contacts will generally also have a wider magnetic gap, which better allows for the variability that looser doors like those on gates or sheds commonly exhibit.