Regularly used to separate central heating and hot water systems or heating circuits between floors, motorised valves come in two varieties; 2 port zone valves and 3 port diverter valves. 2 port zone valves will control the water flow to either the central heating or hot water circuit. A 3 port, mid-position or diverter valve will control the water flow to two destinations simultaneously. A mid-position or diverter valve may be operated via the room/cylinder thermostat or directly through the system programmer. This section contains motorised valves and circuit controls packs from several leading heating controls manufacturers.