Provided is a heat medium circulation device with a simple structure, capable of reducing power consumption in performing an anti-freezing treatment. A first heat medium circuit 2 and a second heat medium circuit 3 are connected via a connector 5. An anti-freezing control unit 42 activates the first pump 22 with the second pump 32 in a stopped state, when preventing the heat medium in the first heat medium circuit 2 from freezing.

A manifold (15) comprising a flow chamber (35) for receiving flow heat exchange water from respective heat sources (3, 5, 7) through first inlet ports (47, 48) and from which the flow heat exchange water is delivered to heat exchange circuits (8, 9) through flow ports (57, 58). A return chamber (36) in the manifold (15) for receiving return heat exchange water from the heat exchange circuits (8, 9) through return ports (57, 58), and from which the return heat exchange water is returned to some of the heat sources (3, 5, 7) through first outlet ports (53, 54). A bypass chamber (37) located in the manifold (15) between the flow chamber (35) and the return chamber (36) receives flow water from the flow chamber (35), which has not been drawn off by the heat exchange circuits (8, 9), through a communicating passageway (40). Heat exchange water from the bypass chamber (37) is returned through second outlet ports (55, 56) to others of the heat sources (3, 5, 7).

A hydraulic separator for hydronic systems for heating and/or cooling, including a hollow body with a casing, internally defining a chamber; at least two first through openings for the delivery of a fluid, and at least two second through openings for the return of the fluid, said first openings and said second openings being made on said casing of the body and being suitable to put in fluid communication said chamber to external circuits by hydraulic connecting means, further includes at least a mobile element suitable for separating said chamber of the body in a first portion and a second portion, in such a way to reduce the opening section of passage and of fluid contact between said first portion and said second portion. The invention further includes a control method tor the hydraulic separator and hydronic systems for heating and/or cooling.

A pressure compensation and mixing device for a fluid heater has a mixing unit and a pressure compensation unit. The mixing unit is configured to mix a fluid guided in the mixing unit. The pressure compensation unit is configured to restrict pressure rising in the fluid. The mixing unit and the pressure compensation unit are integrated in a container unit. A bottom side of the container unit is closed by a bottom portion on which at least one connection is located via which the fluid may be discharged.