Door & Window Sensors

Contact sensors report whether a door or window is open, feeding both security alerts and everyday automations like pausing heating on an open window.

They are the simplest smart home device to install: two magnets, adhesive backing, no wiring. The gap tolerance is the specification to check, usually between 15mm and 30mm. Older frames that have moved out of true can exceed a tight tolerance and produce false "open" reports.

Beyond security, the highest-value use is climate. Pairing a contact sensor with a thermostat so heating pauses when a window opens pays for the sensor quickly in a draughty room, and it is the automation most people keep once they have it.