Window contacts use magnets to detect the opening of windows. Homeowners mount a magnet on the window frame and a metal strip to the window sill, and upon contact, these two devices form an electric circuit.  When the window is shut, the magnetic field closes the circuit between the window contacts, telling the control panel the system is secure.  When the window is opened, the magnet moves away, and the electric circuit is broken.  If your alarm system is activated when the window is opened, the window contacts alert the control panel, which in turn, sounds your alarm.

Placement of Window Contacts

You do not need to fit all windows in your home with window alarm contacts. The location of your home's windows and your personal needs determine the best placement of window contacts.  The following guidelines will help you identify  the best placement of your window contacts if your main concern is keeping burglars out of your home.

• Protect windows that are shrouded by bushes, hedges, or trees

Install window contacts on windows located in dark areas

• Secure windows in the back of your home, which aren't easily seen by your neighbors

If your primary worry is to ensure no one exits your home without your knowledge or consent, especially your teenage child, window contacts ought to be placed on windows in:

• the person's bedroom and bathroom
• the living room or family room
• all areas that can be accessed without your knowledge

Window contacts are a great parenting tool. As teenagers tend push the boundaries set by their parents, but installing window contacts in your home shows your teenage child that you are still in charge.

Two to three sets of window contacts come standard with most security systems, but more are usually needed to properly secure your home. The Home Security Store sells a large variety of additional alarm contacts to integrate into your existing home security system. Window contacts aren't the sole way to secure your windows; oftentimes burglars shatter windows to gain entry into a home.