The VT15 radiator thermostat, which has full CEN Standard approval to EN215, regulates individual radiator output in wet central heating systems. Radiator thermostats are particularly useful in taking advantage of uncontrolled heat gains (e.g. solar gain or an open fire in a living room). Because the valve body design is not sensitive to water flow direction and its radiator tail and copper tube connections are interchangeable, the VT15 radiator thermostat can be mounted vertically or horizontally at either end of the radiator. The VT15 should not be fitted to a radiator in a room where there is a room thermostat. Suitable for two pipe systems only.