FHV-A return temperature limiters with wall-mounted installation boxes enable automatic individual room control for pre-regulated underfloor heating circuits. A sensor element of type RA 2000 (for FHV-A) is required for controlling the room temperature. FHV-R return temperature limiters with wall-mounted installation boxes are designed for floor temperature regulation. A sensor element of type FJVR is required for controlling the return temperature. The installation housings can be used in all wall constructions due to their low installation depth of only 5 cm. The Euro cone connection ensures easy compatibility with all common piping systems.