A hot water apparatus includes a heat exchanger and a housing. A case has a circumferential wall portion, a lower opening, and a flange portion. A case has a flange portion, a circumferential wall portion, and an upper opening. The circumferential wall portion includes a downwardly-extending wall portion inserted into the inside of the circumferential wall portion through the upper opening. In a state where the downwardly-extending wall portion is arranged inside the circumferential wall portion, the lower opening is located below an upper surface of the flange portion.

A 6-way valve (20) comprises two similar 3-way sub-valves (20a, 20b) being mechanically coupled with each other, such that both sub-valves (20a, 20b) are always in the same position, whereby each sub-valve (20a, 20b) has three different valve ports (33, 34, 35) and a valve member (22) with an internal connecting channel (29), which valve member (22) can moved between first and second end positions via an intermediate position such that in said first end position the first (33) and third (35) valve ports are connected with each other by means of said connecting channel (29), in said second end position the second (34) and third (35) valve ports are connected with each other by means of said connecting channel (29), and in said intermediate position said connecting channel (29) is disconnected from said first and second valve ports (33, 34). A simple and effective volume/pressure relief means (28) is provided at one of said valve members (22), which volume/pressure relief means (28) establishes a hydraulic relief connection between said first or second valve port (33, 34) and said third valve port (35) of the respective sub-valve (20a or 20b), when said sub-valves (20a, 20b) are in said intermediate position, and is inactive, when said sub-valves (20a, 20b) are in the first or second end positions.

A plumbing system pressure protection valve assembly that utilizes a unitary body to connect a hot water tank to a cold water supply, a vacuum breaker, and an expansion tank. The assembly includes two ball valves coupled to the unitary body to isolate the hot water tank from the cold water feed and to isolate and permit draining of the expansion tank. The assembly also includes a rod and foot coupled to a tab on the unitary body to provide support for the expansion tank service valve assembly.

A bypass valve is described comprising a delivery duct, a return duct and a central duct connecting the delivery and return ducts for the circulation of a heat-exchange fluid. A first ball valve is placed along the delivery duct and a second ball valve is placed along the return duct, at the intersection between the central duct and the delivery and return ducts. The rotation axes of the balls of the ball valves are perpendicular to each other.

A heat pump assembly (100) is presented. The heat pump assembly (100) comprises a heat pump (110) having a primary side inlet (122) and a primary side outlet (124); a primary side inlet valve assembly (126) comprising: a primary side inlet connection (126a) connected to the primary side inlet (122), a primary side inlet valve first conduit connection (126b) configured to be connected to a first conduit (12) of a thermal energy grid (10), and a primary side inlet valve second conduit connection (126c) configured to be connected to a second conduit (14) of the thermal energy grid (10); a first conduit temperature determining device (105a) configured to measure a local temperature, t.sub.1, of heat transfer liquid of the first conduit (12); a second conduit temperature determining device (105b) configured to measure a local temperature, t.sub.2, of heat transfer liquid of the second conduit (14); and a controller (108). The controller is configured to: receive hand t.sub.2 from the first and second conduit temperature determining devices (105a; 105b), receive information pertaining to whether the heat pump (110) is a heating mode heat pump or a cooling mode heat pump. The controller is configured to upon the heat pump (110) is the heating mode heat pump and upon t.sub.2>t.sub.1 set the primary side inlet valve assembly (126) to fluidly connect the primary side inlet valve first conduit connection (126b) and the primary side inlet connection (126a), primary side inlet valve assembly (126) to fluidly connect the primary side inlet valve or upon the heat pump (110) is the heating mode heat pump and upon t.sub.1>t.sub.2, set the second conduit connection (126c) and the primary side inlet connection (126a). The controller is configured to upon the heat pump (110) is the cooling mode heat pump and upon t.sub.1>t.sub.2, set the primary side inlet valve assembly (126) to fluidly connect the primary side inlet valve second conduit connection (126c) and the primary side inlet connection (126a), or upon the heat pump (110) is the cooling mode heat pump and upon t.sub.2>t.sub.1, set the primary side inlet valve assembly (126) to fluidly connect the primary side inlet valve first conduit connection (126b) and the primary side inlet connection (126a).

A 6-way valve (20) comprises two similar 3-way sub-valves (20a, 20b) being mechanically coupled with each other, such that both sub-valves (20a, 20b) are always in the same position, whereby each sub-valve (20a, 20b) has three different valve ports (33, 34, 35) and a valve member (22) with an internal connecting channel (29), which valve member (22) can moved between first and second end positions via an intermediate position such that in said first end position the first (33) and third (35) valve ports are connected with each other by means of said connecting channel (29), in said second end position the second (34) and third (35) valve ports are connected with each other by means of said connecting channel (29), and in said intermediate position said connecting channel (29) is disconnected from said first and second valve ports (33, 34).

A simple and effective volume/pressure relief means (28) is provided at one of said valve members (22), which volume/pressure relief means (28) establishes a hydraulic relief connection between said first or second valve port (33, 34) and said third valve port (35) of the respective sub-valve (20a or 20b), when said sub-valves (20a, 20b) are in said intermediate position, and is inactive, when said sub-valves (20a, 20b) are in the first or second end positions.

The disclosed technology includes an on-demand water heater which uses a heat pump to heat the fluid. The on-demand heat pump water heater can have a low fluid capacity heating chamber which has an inlet and an outlet, a heat pump for heating the fluid, and a controller to control the heat pump and maintain the temperature of the fluid at a predetermined temperature. The on-demand heat pump water heater can include one or more temperature sensors, flow sensors, fluid mixing valves, or supplemental heat sources.

A valve device includes: a case having a valve chamber and first to third water communication ports communicating with the valve chamber; first and second valve bodies disposed in the valve chamber; and a shaft body connected with the first valve body. The first valve body is rotated about a central axis of the shaft part. The second valve body is rotated about the central axis together with the first valve body. When rotated about the central axis in a first angle region, the first valve body changes a first flow rate, i.e., a flow rate of water between the first and third water communication ports, and a second flow rate, i.e., a flow rate of water between the second and third water communication ports. When the first valve body is rotated about the central axis in a second angle region, the second valve body changes the second flow rate.

A recirculation valve according to the present invention comprises: a warm-water housing communicating with a warm-water supply tube for supplying warm water generated by heating raw water, thereby forming a warm-water channel provided such that warm water flows through the inside thereof; a direct-water housing communicating with a direct-water supply tube through which direct water (raw water) is supplied, thereby forming a direct-water channel provided such that direct water flows through the inside thereof; a recirculation housing through which the warm-water channel and the direct-water channel communicate with each other, thereby forming a recirculation channel provided such that warm water in the warm-water channel flows to the direct-water channel; and a water-pressure opening/closing body provided inside the direct-water housing to be able to move according to a reference direction in order to close or open the recirculation channel. The water-pressure opening/closing body comprises an upstream pressurizing unit and assuming that the direction in which direct water flows into the direct-water channel from the direct-water supply tube is a reference direction, a downstream pressurizing unit positioned in the reference direction from the upstream pressurizing unit. The inner surface of the direct-water housing, which defines the direct-water channel, comprises an upstream inner surface positioned on the outside of the upstream pressurizing unit when the water-pressure opening/closing body is positioned to open the recirculation channel, and a downstream inner surface positioned in the reference direction from the upstream inner surface. A stepped portion is formed between the upstream inner surface and the downstream inner surface so as to correspond to a stepped portion formed between the upstream pressurizing unit and the downstream pressurizing unit.

A hot water recirculation system for a house or other building causes water to be recirculated to a water heater for reheating until the water is above a set-point temperature at which time the heated water is made available for use at a faucet or other hot water plumbing fixture. Recirculation of hot water takes place only when there is demand for hot water at a hot water plumbing fixture. A flow switching module for use in the hot water recirculation system can selectively direct water supplied to the flow switching module from a water heater either to a hot water plumbing fixture or to return piping for returning the water to the water heater. The flow switching module may be operated manually, automatically, or semi-automatically.