A circulation pump assembly includes a first inlet (84), an outlet (80), an electric drive motor (30) and at least one impeller (68; 100) driven by the drive motor (30). The circulation pump assembly has at least one first flow path (26; 48) positioned in a connection between the first inlet (84) and the outlet (80) for increasing the pressure of a fluid. The circulation pump assembly has a second inlet (86). The at least one impeller (68; 100) has at least one second flow path (28; 50) for increasing the pressure of a fluid, which is positioned in a connection of the second inlet (86) to the outlet (80). A heating system is provided having a circulation pump assembly of this type.

Hydraulic system comprising a three-way valve, the three-way valve comprising a first port for the connection to a primary heat exchanger through the circulation pump, a second port and a third port for connection to the heating circuit and to a secondary heat exchanger, respectively. The three-way valve is switchable between two positions in which the first port is in fluid communication with the second port or with the third port. The three-way valve is responsive to the pressure applied by a circulation pump, and has a displaceable obstructing member that may be moved due to transitions between an off-state and an on-state of the circulation pump. The obstructing member comprises a pair of sealing surfaces facing away from each other and suitable to engage reciprocatingly respective opposed seats of the three-way valve.

Three-way valve drivable by a pump, switchable between at least two switch positions wherein a first port is selectively in fluid communication with a second port or with a third port. The three-way valve comprises a movable support and a pair of obstructing members carried by the movable support, at least one of which is responsive to the pressure applied by the pump at the first port, at least one of the movable support and obstructing members to being movable due to transitions between an off-state and an on-state of the circulation pump. The obstructing members are adapted to engage reciprocatingly the respective seats of the three-way valve. The obstructing members are capable of changing shape synchronously when the pump switches from the off-state to the on-state.

A hydraulic system includes a circulation pump assembly (2) provided with a speed controller (4, 26), a hydraulic circuit (A, B) connected to the circulation pump assembly (2) as well as a mechanical switch device (86, 88; 120, 122; 120, 122) which is subjected to pressure from a fluid in the hydraulic circuit (A, B) and which can be moved into at least two different switch positions. The mechanical switch device (28; 86, 28; 120, 122) can be moved by the circulation pump assembly (2) by way of a hydraulic coupling via the fluid. The speed controller is configured to initiate a movement of the switch device (86, 88; 120, 122; 120, 122) by way of at least one hydraulic force acting thereon and causing a movement of the switch device (86, 88; 120, 122; 120, 122), produced via the hydraulic circuit, via a speed adaptation of the circulation pump assembly.

A mixing device includes a first inlet (84) and a second inlet (86) inlet and an outlet (80). The first inlet (84) is connected to the outlet (80) via a first flow connection and the second inlet (86) is connected to the outlet (80) via a second flow connection. A circulation pump assembly (24; 46) includes an electric drive motor (30), a control device (34), for controlling the speed of the drive motor (30), and at least one impeller (68; 100) driven by the drive motor. The at least one impeller (68; 100) is positioned in the first flow connection. The flow connections are configured such that at least one hydraulic pressure generated by the impeller (68; 100) in the first flow connection acts as hydraulic resistance in the second flow connection.

A centrifugal pump assembly includes an electrical drive motor (4, 6), an impeller (14) which is driven by the electrical drive motor (4, 6) as well as with at least one valve element (18) which is directly or indirectly movable along a first movement path between at least two switching positions, by the electrical drive motor (4, 6). At least a part of the valve element (18) is additionally movable along a second movement path which is different to the first movement path, between a released position, in which the valve element is distanced to at least one contact surface and a bearing position, in which the valve element bears on the at least one contact surface.

A centrifugal pump assembly includes an electrical drive motor (4, 6), an impeller (14) which is driven by the drive motor and a pump casing (12) surrounds the impeller and including two branches (27, 32, 34). A movable valve element (18) is arranged in the pump casing and is movable between two switching positions, in which the flow paths through the two branches (27, 32, 34) are opened to a different extent. The valve element (18) is configured and arranged in the pump casing (12) such that it separates a suction chamber (24) which is connected to a suction side of the impeller (14) from a delivery chamber (26) which is in connection with the delivery side of the impeller (14). The valve element (18) is mechanically and/or hydraulically coupled to the drive motor (4, 6) for at least a movement between the two switching positions.

The system includes: a heat pump unit; a hot water supply heat exchanger; heating heat exchangers; a pump; heat medium pipes that connect a discharge side of the pump, the heat pump unit, the hot water supply heat exchanger, the heating heat exchangers, and a suction side of the pump in order; a first bypass pipe that bypasses the hot water supply heat exchanger from the heat medium pipe; a second bypass pipe that bypasses the heating heat exchangers from the heat medium pipe; a four-way valve that regulates flow distribution of the heat medium between the hot water supply heat exchanger and the first bypass pipe 22, and between the heating heat exchangers and the second bypass pipe; and a control unit for controlling the four-way valve in accordance with a hot water supply request and a heating request.

A pump assembly includes pump casing (2), an impeller (14) rotatably arranged in the pump casing, a two rotation directions (A, B) electrical drive motor connected to drive the impeller and a valve arrangement (28) arranged in the pump casing to switch a flow path downstream of the impeller between two exits (24, 26) of the pump casing, depending on a rotation direction of the impeller. The valve arrangement includes a first movable valve element (34) at a first exit (24) and a second movable valve element (36) at a second exit (26). The first valve element partly closes the first exit in a closed position and is movable into an opened position by flow in the first rotation direction and the second valve element partly closes the second exit in a closed position and is movable into an opened position by flow in the second rotation direction (B).

In a method for operating a heat pump system, heat can be supplied to a heating circuit medium using a heat pump; a heating circuit medium flows through a heating circuit; in a first operating mode of the heat pump system, heat is supplied to at least one heat sink located in the heating circuit between a flow line of the heating circuit and a return line of the heating circuit; in a second operating mode of the heat pump system, heat is supplied to a buffer located in the heating circuit between the flow line and the return line and in parallel with the at least one heat sink. In a third operating mode of the heat pump system, an electrical heating device is used to supply heat to the heating circuit medium located in the buffer in order to start the heat pump.