The Snow Detector and Melting Control 667 from tekmar Control Systems is designed to control a single zone snow melting system with a single boiler. To provide slab and boiler protection, the 667 uses a variable speed injection pump. The system may be started manually or automatically through the use of a Snow/Ice Sensor. Multiple 667s can be combined with a single staging control to accommodate large, multi-zone systems. tekmar Control Systems Ltd.