A hybrid tank and tankless hot water system with an inlet bypass and an outlet bypass are configurable between a hybrid heater configuration and an on-demand configuration. In the hybrid heater configuration, the inlet bypass supplies cold water to a cold water inlet of a storage tank and the outlet bypass supplies hot water from an outlet manifold to a recirculation inlet of the storage tank. In an on-demand configuration, the inlet bypass supplies cold water to a cold water manifold for directly providing cold water to hot water heaters and the outlet bypass supplies hot water from the outlet manifold directly to a system hot water outlet. In the bypass configuration, a storage tank and/or recirculation pump are fluidically isolated from one or more hot water heaters to facilitate their maintenance, repair, replacement while still supplying hot water on demand from the hot water heaters.

A hot water supply apparatus of the present invention includes: a direct water inlet pipe into which direct water is introduced; a heat exchanger for heating direct water introduced through the direct water inlet pipe with combustion heat of a burner; a hot water supply pipe for discharging the hot water heated in the heat exchanger; a bypass pipe connected between the direct water inlet pipe and the hot water supply pipe so as to mix a part of the direct water introduced through the direct water inlet pipe with the hot water discharged through the hot water supply pipe; and a pressure reducing valve provided on the bypass pipe and configured to reduce the pressure of water passing through the inside of the bypass pipe to supply the water to the hot water supply pipe when hot water is supplied.

A hot water supply apparatus has: a thermo-sensitive valve which is connected in parallel to a cold water delivery pipe and a hot water delivery pipe and which is closed when the hot water temperature to flow inside the valve is above a predetermined temperature to thereby shut off communication between the cold water delivery pipe and the hot water delivery pipe; and a circulation pump. By operation of the circulation pump, water circulation takes place from a heat exchanger through the hot water delivery pipe, a return pipe, the circulation pump, and a cold water supply pipe back to the heat exchanger. When the thermo-sensitive valve is open, water circulation takes place also through the thermo-sensitive valve. Instantaneous hot water supply operation is finished when an amount detected by a flow sensor falls below a predetermined amount during the instantaneous hot water supply operation.

A water heating and treatment system with UV lamp water treatment sanitation for suppression of pathogens and undesired bacterial content in a domestic hot water system includes a water heater, and a cold water supply line to supply water to the water heater. The cold water supply line includes a UV sanitation lamp. A single or multiple temperature regulating mixing station supplies a temperature regulated heated water to one or multiple temperature zones. A three-way return water diverter valve provides a portion of a re-circulated hot water from a hot water recirculation line including a temperature sensor to the single or multiple temperature regulating mixing station and a remaining portion of the re-circulated hot water to the drain. A method for treating hot water to suppress pathogens and undesired bacterial content in a domestic hot water system is also described.

A fluid heating apparatus according to an embodiment disclosed herein may include a burner, a heat exchanger, a first flow rate sensor that detects a flow rate of a fluid supplied to the heat exchanger, a temperature sensor that detects a temperature of a fluid discharged from the heat exchanger, and a controller that controls a first pump provided in an internal circulation flow path on the basis of the flow rate detected by the first flow rate sensor to manage the flow rate of the fluid supplied to the heat exchanger and controls an operation of the burner on the basis of the temperature detected by the temperature sensor.

A water heater system includes a controller configured to integrate control of both recovery and recirculation operations of a recovery pump and a recirculation pump. As such, a separate device, installation location, and power source (e.g., available outlet) is not needed with the controller. Because a single controller is configured to control both recovery and recirculation operations, additional control functions are available. The controller may be in communication with an internal controller of the water heater and configured to receive an error notification upon abnormal operation of the water heater. The controller can stop recovery and recirculation operations in response to an error notification, unlike with traditional water heating systems which may otherwise continue to function. The recovery and recirculation operations are based on a setpoint temperature of the water heater such that changes made to the setpoint temperature will automatically adjust in the recovery and recirculation operations.

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.

Surface disinfecting and sterilizing devices, systems and methods are provided. Surface disinfecting systems provided include a control system with one or more camera(s) and an aimable, rapid disinfecting and/or sterilizing device(s), all of which may be installed within a public or other high-traffic environment, and configured to monitor and treat all touched surfaces within the environment. The control system determines a cooling time for each such touched surface and type of treatment, and prevents treatment from occurring when treated surface(s) are accessible by human body part(s) or other objects within the environment. The invention may be provided on or in any form of user interface that may be physically touched by a user. For example, in some embodiments, the invention may be provided to treat, disinfect and sterilize door handles, touchscreens, or other user controls, and any other user interfaces bearing a risk of carrying microbes and pathogens.

A hot water supply device includes a heater, a water channel, a mixing valve unit, and a circulation mechanism. The mixing valve unit has a valve member and a drive unit configured to drive the valve member to change a mixing ratio of supply water heated by the heater and unheated water. The circulation mechanism has: a connection passage that connects the water channel to the heater by being branched from a part of the water channel between the mixing valve unit and the heater; an on-off valve that opens and closes the connection passage; and a pump configured to return the supply water remaining in the water channel through the connection passage to the heater. A drive amount acquisition unit acquires a drive amount of the drive unit, and a controller controls the circulation mechanism based on the drive amount acquired by the drive amount acquisition unit.

A water heater system includes a water heater having a first water outlet and a second water outlet. The water heater system further includes a flow detection device coupled to the first water outlet to detect a water flow through the first water outlet. The water heater system also includes a flow control valve fluidly coupled to the second water outlet. The flow control valve is configured to control a flow of water through the second water outlet based on whether the water flow through the first water outlet is detected by the flow detection device.