Non-electric TRVs

NON-ELECTRIC THERMOSTATIC RADIATOR VALVES or TRVs are devices which can be added to a steam or hot water radiator to control temperature at the individual radiator. A wax element in the valve expands and contracts with ambient room temperature, opening and closing the valve to maintain whatever temperature is set on the operating dial. These devices are useful in control of over-sized or overheating radiators, as they shut the radiator off when the desired room temperature is reached. They are installed between the radiator and air vents on steam units and in place of the hand valve on hot water radiators.

Rooms can be individually zoned simply by installing trvs on their radiators. The operating head of the valve can be placed directly on the radiator or the valve can be operated remotely with a wall-mounted dial, attached to the valve via capillary tube.