A 2-Port motorised valve supplied with 28mm compression fittings. It is to be used for the flow control of central heating or hot water in 'S plan' central heating systems. The valve operates in conjunction with either a room thermostat or a cylinder thermostat. It will open only when in demand from the thermostat with the actoin of a geared synchronous motor and closes by a spring return mechanism. When the valve is in the open position, a limit switch operates to switch on the heat source. Please note that this valve must be installed according to the direction of the flow as indicated by the arrow on the valve body. It is only suitable for open vented or sealed pumped systems.The valve comes with a 5 core colour coded flexible cable at a length of 1 metre for ease of installation. Power consumption of the unit at 6W, with a temperature range of 5°C to 88°C and a maxiumum differential pressure of 1 Bar.Both the actuator heat and synchronous motor are replaceable."