New forms of self-sterilizing and antiseptic surfaces are provided. In some embodiments, a handled surface or GUI comprises internal hardware performing a heavy rinse of the handled surface triggered by an end-of-use function. In other embodiments, pressure on a handled surface instead causes the surface to uniformly exude water and other antiseptic compositions from a refillable source.

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.

Technologies for use with a hot water recirculation system containing a hot water source, a booster pump downstream from the sensor, a conduit connecting the booster pump and water source, a flow sensor external to the conduit for sensing water flow within the conduit, and a plumbing fixture downstream from the pump are provided. The technologies enable a controller to couple to the sensor and the pump, and operate in a calibration mode and a control mode. Such operations can increase energy efficiency of the pump and increase operational longevity of the pump.

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.

Water quality maintenance system are disclosed herein. The systems are configured to automatically switch between an open state allowing for purging of water from a water line and a closed state preventing water flow. The systems comprise a controller is configured to automatically generate a control signal and a purge valve comprising an electromagnetic actuator in electromechanical communication with the controller. Also disclosed herein are fixtures comprising the systems and methods of using the systems.

Technologies for use with a hot water recirculation system containing a hot water source, a flow sensor downstream from the source, a booster pump downstream from the sensor, and a plumbing fixture downstream from the pump are provided. The technologies enable a controller to couple to the sensor and the pump, and operate in a calibration mode and a control mode. Such operations can increase energy efficiency of the pump and increase operational longevity of the pump.

Disclosed is a two-way check/bypass valve assembly connected between the hot and cold-water standpipes under the sink that allows convective circulation of hot water from an existing water heater, through the existing hot water distribution pipes, through the valve assembly to the cold water standpipe, through the existing cold water standpipe and distribution pipes, and back into the water heater. The convective water flow is induced by the temperature difference between the hot water in the pipe rising above the water heater, and the slightly cooled, and denser, water flowing back down into the water heater. The valve will allow this low circulation water flow so long as both hot and cold faucets at the outlet are closed, and will prevent any cross flow between the hot and cold pipes under the sink when either the hot or cold faucet is opened.

Disclosed is a two-way check/bypass valve assembly connected between the hot and cold-water standpipes under the sink that allows convective circulation of hot water from an existing water heater, through the existing hot water distribution pipes, through the valve assembly to the cold water standpipe, through the existing cold water standpipe and distribution pipes, and back into the water heater. The convective water flow is induced by the temperature difference between the hot water in the pipe rising above the water heater, and the slightly cooled, and denser, water flowing back down into the water heater. The valve will allow this low circulation water flow so long as both hot and cold faucets at the outlet are closed, and will prevent any cross flow between the hot and cold pipes under the sink when either the hot or cold faucet is opened.

A hot-water supply system 1 comprises a temperature responsive valve 61 provided in a first bypass passage 60, an orifice 31 provided in a second bypass passage 30, a flow rate sensor 24 provided in a water supply passage 11 downstream from a connection point with the second bypass passage 30, a circulating pump 33 provided in the water supply passage 11 downstream from the connection point with the second bypass passage 30, and a controller 4. The controller 40 operates the circulating pump 33 and executes circulation heating operation for operating a burner to heat the hot water circulating through a circulation circuit 80, when a flow rate detected by the flow rate sensor 24 is equal to or more than a specified flow rate.