A bypass valve is for support between hot and cold water lines that connect to respective hot and cold fixtures. The bypass valve includes a valve body having an internal chamber, a hot water inlet port, a hot water outlet port and a discharge port; a bi-metal spring; a support member for mounting the bi-metal spring within the internal chamber of the valve body; and a shuttle mounted to the bi-metal spring and constructed and arranged to mate with the discharge port in a closed position of the bi-metal spring. The bi-metal spring assumes an open position to disengage from the discharge port at a predetermined water temperature to enable the hot water to discharge through the discharge port to the cold water line.

The invention is a water conservation system for conserving water supplied by a hot water tank, the system functioning to selectively open a diverter fluid path extending between a hot water supply line and a cold water supply line, and operating a return module to return unheated water in the hot water supply line back to the hot water tank using the cold water supply line until the water in the hot water supply line flows hot.

The concepts relate to reducing energy loss associated with hot water systems. One example is manifest as a system with an automatic hot water recovery apparatus and selective hot water isolation devices. In one example a selective hot water isolation device is configured to be connected in fluid flowing relation with a first water line and a second water line and the selective hot water isolation device is configured to control water cross-over from the second water line into the first water line based upon water flow through the first water line.

A water tempering system comprising a mixing tank located downstream from the main hot water storage tank, the mixing tank receiving a supply of hot water at a first temperature and a supply of cold water, the hot water and cold water supplies mixing within the mixing tank to provide a source of tempered hot water at a reduced, second temperature that is discharged from the mixing tank for distribution and use within an overall system. The amount of cold water directed to the mixing tank is controlled by a variable frequency drive pump which can adjust depending on system demands to ensure that sufficient cold water is directed to the mixing tank to ensure adequate mixing occurs to bring the temperature of the hot water to the second reduced temperature even during periods of low demand.

A water heating system having a system inlet pipe (1.002), a hot water delivery pipe (1.003) and a hot water return pipe (1.006) connected to a building hot water distribution network (1.024); the water heating system including one or more water heaters (1.001), the or each water heater having a heater inlet (1.022) and a heater outlet (1.023), a hot water return pipe (1.006) connected between the system inlet and delivery outlet via the building hot water distribution network to form a close loop hot water supply-return circuit; a pump (1.005) connected to circulate water through the hot water supply-return circuit whereby the pump can circulate water through one or more of the water heaters; a valve means (1.007) [a first non-return valve] adapted to prevent inlet water (water delivered to the system inlet) from flowing into the hot water return pipe or the building hot water distribution network.