Abstract: The invention relates to a hydraulic separator to be fitted between a primary liquid circuit and a secondary liquid circuit, in such a manner that the first and secondary liquid circuits are hydraulically independent. The hydraulic separator has an elongate body with an internal space which is delimited by a wall. In the internal space there is a feed port leading to the primary liquid circuit and a discharge port leading from the primary liquid circuit, which are located substantially on one longitudinal side of the hydraulic separator. Also in the internal space there is a feed port leading to the secondary liquid circuit and a discharge port leading from the secondary liquid circuit, which are located substantially on a different longitudinal side of the hydraulic separator. The feed port leading to the primary liquid circuit and the discharge port leading from the secondary liquid circuit are located substantially at a first height region of the hydraulic separator.