Can monitor up to 3 systems at one time when they are temporarily connected in series A white light indicates the monitor is operating ? HOW DOES IT WORK? The Cable Monitor constantly measures the continuity of the floor heating cable. Tighten the screws to hold the wires in place. If the alarm sounds, stop work and consult the operation manual. It will give you peace of mind while installing the floor warming system. One 9v alkaline battery is required (For example ASIN: B00MH4QM1S). Simple connection of heating wire to the cable monitor, with convenient on/off switch. Compatible with most radiant floor heating mats, cables, and floor coverings Connect the system leads to the monitor prior to installation. A green light to indicate GO and a Red light to indicate STOP, there's damage ? HOW IS IT CONNECTED? Each lead wire from the floor heating cable is connected into the connection points on the Cable Monitor. The Cable Monitor is a continuity tester, which is easily connected to the heating system, and immediately sounds an alarm and shows a red light if the cable is damaged in any way during the installation of the radiant heating system or of the floor. HeatTech HTCM is an alarm unit used for monitoring the heating cable/mat integrity during the installation process HEATIT Floor Heating Alarm Monitor - Cable Screamer For Radiant Heating Installation Cable Monitor For Electric In Floor Heating System Installation Circuit Check Alarm Screamer Monitors Continuity Insulation Compatible Electric Underfloor H 8b4fd4be F440 4bac A82e 67a3f3e7caf8.266700c221d7287048e860a9af7449a2 The Installation Monitor sounds an alarm if the Heating Wire is cut or damaged, allowing for easy repair BEFORE the mat is covered with Mortar & Tile