What is the difference between manual and thermostatic radiator (TRV) valves?
A thermostatic radiator valve measures the room temperature and adjusts the flow accordingly. It does this by means of a sensor in the centre of the handle. As the room temperature rises expansion causes a rod to push down on the valve mechanism restricting the inlet flow of hot water. The desired temperature is set by turning the handle. At the outlet (return) end of the radiator is attached the lockshield valve. This is adjusted by the plumber to balance flow rates through the system, ensuring all radiators get an adequate share of the available hot water. Thermostatic radiator valves are recommended by plumbers and the government as energy saving. They are, if the temperature is set and maintained. In practice people may think it’s a little chilly then turn the valve full on. Left fully open they will save no energy at all. The term thermoregulating valve is also used to mean thermostatic radiator valve. Strictly speaking a thermoregulating valve has both hot and cold supplies, such
