A system produces domestic hot water and includes a tank having top and bottom portions and containing heat storing fluid, and a tapping unit including first and second tapping coils. The first tapping coil is immersed in the bottom portion of the tank. The second tapping coil is fluidly connected in series to the first tapping coil by a connection pipe, and to the hot water port, and is immersed the top portion of the tank A switching device switches between a first state in which water flows from the cold water port through only first tapping coil to the hot water port, and a second state in which water flows from the cold water port through the first tapping coil and, after flowing through the first tapping coil, through to the second tapping coil to the hot water port.

A boiler loop system including a primary-secondary piping loop interface apparatus including a flow diversion device, and a drain valve, and a drain port in branches from a circumferential sidewall. In an embodiment, supply branch piping and return branch piping connect the primary-secondary piping loop interface apparatus to a boiler and provide attachment points for auxiliary plumbing equipment. In an embodiment, the boiler loop is integrated into the primary loop.

A circulation pump assembly for a heating and/or cooling system includes an electric drive motor (108) and a connected pump housing (106) in which at least one impeller (118) is situated and which comprises a first inlet (112) and a first outlet (114). The pump housing (106) includes a second inlet (122) which is connected in an inside of the pump housing (106) at a mixing point (130) to the first inlet (112). A regulating valve (134), which is designed for regulating the mixing ratio of two flows mixing at the mixing point (130), as well as a control device, which controls the regulating valve (134) for regulating the mixing ration, are arranged in the pump housing (106). A hydraulic manifold is provided with such a circulation pump assembly.

A circulation pump assembly for a heating and/or cooling system includes an electric drive motor (108) and a connected pump housing (106) in which at least one impeller (118) is situated and which comprises a first inlet (112) and a first outlet (114). The pump housing (106) includes a second inlet (122) which is connected in an inside of the pump housing (106) at a mixing point (130) to the first inlet (112). A regulating valve (134), which is designed for regulating the mixing ratio of two flows mixing at the mixing point (130), as well as a control device, which controls the regulating valve (134) for regulating the mixing ration, are arranged in the pump housing (106). A hydraulic manifold is provided with such a circulation pump assembly.

A pump assembly includes an impeller (18), which for rotation is connected to an electrical drive motor (20) which can be driven in two rotation directions (A, B) and a valve (10) situated in an inlet of the pump assembly. The valve includes a valve element (48) movable between at least two switch positions and is connected for movement to a drive element (36, 60) subjected to the flow produced by the impeller (18). The valve element (48), in at least a first of the two switch positions, closes an inlet channel (44, 46) of the pump assembly (12) and is arranged such that the movement direction into this first switch position corresponds to the flow direction (S1, S2) through this inlet channel (44, 46). A hydraulic system is provided with two circuits and such a pump assembly. The valve serves as a switch-over valve between the two circuits.

A hydraulic system includes at least one pump assembly and a switching device which includes at least two switch positions. The switching device is configured such that on operation of the pump assembly in a first operating condition, the switching device is held in a stable manner in each of the at least two switch positions in each case by the hydraulic forces in the system. In a second operating condition of the pump assembly, the switching device is moved from a first switch position into a second switch position, assisted by switching energy stored in the first operating condition. The hydraulic system is configured such that in the first operating condition, the switching energy is stored independently of a switching-over of the switching device between the switch positions. A method is provided for operating such a hydraulic system.

A method switches a switching device (4) between two switch positions in a hydraulic system. The hydraulic system apart from the switching device (4) includes a pump assembly (2). The pump assembly (2) can assume at least two different operating conditions. A switching-over of the switching device (4) is initiated by the pump assembly (2) via the hydraulic system. The switch positions of the switching device (4) are reached depending on a stay duration of the pump assembly (2) in at least one of the two operating conditions. Further, a hydraulic system for carrying out the method is provided.

A boiler loop system including a primary-secondary piping loop interface apparatus including a flow diversion device, and a drain valve, and a drain port in branches from a circumferential sidewall. In an embodiment, supply branch piping and return branch piping connect the primary-secondary piping loop interface apparatus to a boiler and provide attachment points for auxiliary plumbing equipment. In an embodiment, the boiler loop is integrated into the primary loop.

A heating system combines a heat source for applying heat energy to a supply of heat transfer fluid including a polyol having five or less pendant hydroxyl groups and a polydimethylsiloxane and a pump that moves the heat transfer fluid through conduits to a heat exchanger. In one configuration, the heating system has a primary circuit including the heat source, delivery line, pump, heat exchanger and return line, and a sub-circuit including a bypass line interconnecting the delivery line and the return line to provide a flow path bypassing the heat source. The sub-circuit includes the bypass line, a portion of the delivery line, the pump, the heat exchanger, and a portion of the return line. Control valves and a control mechanism direct the flow of fluid between the primary and sub-circuit. The heat transfer fluid is a blended mixture of 5-15% glycerin, 20-40% propyl glycol and 45-75% silicone.

A hydraulic valve device includes a first inlet port (20) and a second inlet port (22) and a valve element (24) for selectively closing one of the first and the second inlet port. The valve element (24; 24) is rotatable between two valve positions such that a surface of the valve element is moved in a direction parallel to openings of the inlet ports. The valve element includes two separate sealing portions (72, 74), a first sealing portion (72) for closing the first inlet port and a second sealing portion (74) for closing the second inlet port. The two sealing portions are arranged such that in a first valve position a first sealing portion closes the first inlet port and in a second valve position a second sealing portion closes the second inlet port. A centrifugal pump device includes such hydraulic valve device.