My door/window contact does not work.

Alarm systems, Sensors and accessories / Alarms, Detectors /

Make sure there is a battery in your detector. The ES-D3B is powered by 1 23A battery.
If there is already a battery in your detector, make sure the battery comply with the requirements (23A). If it does, make sure you have registered the detector in the control panel of your alarm system. To register the detector in the control panel, we advise you to use our Connection Assistant