FHV provides an economical method of incorporating a radiant floor heating system into an existing hot water or radiator system. FHV self-acting regulators are well suited to handle underfloor heating temperature in single rooms(bathrooms, entry ways,kitchens). FHV control valves are available in two versions: FHV-A control valves are suited to control individual underfloor heated rooms.The FHV-A is placed on the supply side of a floor heating system, and is capable of providing hydraulic balancing via the FHV-A’s integral pre-setting feature. A standard RA 2000 operator is fitted to the FHV-A valve. FHV-R valves are designed for systems using floor heating in conjunction with radiators.The valve is place on the return side of the radiant floor system.The valve’s operator, FJVR, senses the return fluid temperature of the system and regulates the valve appropriately. When the FHV-R is used for a radiant heating system, the maximum floor heated area should not be greater than 110 sq. ft.