Provided is an instant water boiling device, which comprises: an instant water boiler provided with a water inlet and a water outlet communicated with a faucet; a control panel arranged on the faucet; and a controller in signal connection with the control panel and the instant water boiler. According to the invention, the control panel is separated from the instant water boiler, which is convenient to install, the instant water boiler with a larger volume can be installed in a cabinet under a tabletop, which saves a space of the tabletop, and meanwhile, the control panel is installed on the faucet, which is convenient for a user to operate the control panel, thus facilitating the operation, simplifying the installation, and saving the space of the tabletop.

A water heater including an inflow terminal for connecting a tankless water heater to a cold water supply and an outflow terminal for connecting the tankless water heater to a tap. A fluid channel proves a fluid connection from the inflow terminal to the outflow terminal. A heat element arrangement is arranged at or within at least a section of the fluid channel for transferring heat to fluid present within the fluid channel. An electronic controller is configured to control a heating power provided to the heat element arrangement. A flow sensor is arranged at or within the fluid channel downstream the heat element arrangement. The electronic controller is further configured to detect the presence of air bubbles within the fluid channel based on a change of a flow signal provided by the flow sensor and to adapt the heating power provided to the heat element arrangement in reaction to the determination of air bubbles.

A water heater can include a housing and a heating system disposed within the housing, where the heating system is configured to heat a fluid. The water heater can also include a switch coupled to the heating system, where the switch operates between a first position during normal operations and a second position during an outage. The water heater can further include a primary power source coupled to the switch, where the primary power source is configured to provide primary power to the heating system through the switch during the normal operations. The water heater can also include an uninterruptible power supply (UPS) coupled to the switch, where the UPS is configured to provide reserve power to the heating system through the switch during the outage, and where the UPS is integrated with the housing.

A scale adhesion prevention operation of a circulation pump operated in an instant hot water operation is efficiently and appropriately performed. An instant hot water circulation path is formed to bypass a hot water tap outside a hot water supply device and to pass through a heat exchanger inside the hot water supply device by operating a circulation pump when the hot water tap is closed. A controller performs a protection operation which operates the circulation pump when a first condition in which stop of the circulation pump is continued for a first time is satisfied and a second condition related to stop of a hot water supply operation is further satisfied.

A tankless water heater with an impeller flowmeter having multiple K factors significantly improving the accuracy of flowmeter readings, particularly at low water flow rates, such as under 1 gallon per minute. Rather than use a single K factor impeller flowmeter in a tankless water heater that is particularly inaccurate at low flow rates, this disclosure provides an impeller flowmeter with multiple K factors to obtain precise flow rate readings to precisely control heating of the water at low flow rates. The flowmeter has an onboard memory with multiple K factors stored for a controller to access and read. These multiple K factors are established for flowrates across the entire dynamic range of the flowmeter at the time it is manufactured. Just enough K factors are determined to provide good curve fitting. The flowmeter onboard memory is programmed with the multiple K factors.

A tankless water heater with an impeller flowmeter having multiple K factors significantly improving the accuracy of flowmeter readings, particularly at low water flow rates, such as under 1 gallon per minute. Rather than use a single K factor impeller flowmeter in a tankless water heater that is particularly inaccurate at low flow rates, this disclosure provides an impeller flowmeter with multiple K factors to obtain precise flow rate readings to precisely control heating of the water at low flow rates. The flowmeter has an onboard memory with multiple K factors stored for a controller to access and read. These multiple K factors are established for flowrates across the entire dynamic range of the flowmeter at the time it is manufactured. Just enough K factors are determined to provide good curve fitting. The flowmeter onboard memory is programmed with the multiple K factors.

The present disclosure is directed to a hot water recirculation system with a return tee. The system includes a water heater, several supply lines, and a return tee. The hot water supply line is communicatively coupled to the water heater and at least one fixture and provides heated water from the water heater to the at least one fixture. The cold water supply line provides cold water from a cold water source to the water heater. Finally, the return line is communicatively coupled to the hot water supply line and delivers cooled water from the hot water supply line to the water heater. A return tee is communicatively coupled to the return line, the cold water supply line, and the water heater. This return tee provides cooled water from the return line and cold water from the cold water supply line to the water heater, which heats the water.

Apparatus for rapid heating of a liquid including a heat source, a liquid flowpath defining element defining a liquid heating flowpath therein having a liquid inlet and a liquid outlet, a collection of flexible elongate thermal conductors located within the flowpath, the collection of flexible elongate thermal conductor portions being thermally coupled to the heat source and defining multiple liquid heating passageways through the flowpath whose configurations and cross-sectional dimensions change over time, thereby being resistant to clogging.

A hot water system for a bidet having a housing is provided. The hot water system includes: a water inlet pipe connected to a faucet; a flow path guide tank located at a lower portion in the housing so that water introduced into the water inlet pipe flows; a sheath heater provided in the housing and configured to heat water discharged from the flow path guide tank; and a water outlet pipe configured to supply water heated by the sheath heater to the outside. The flow path guide tank has a flow path guide hole formed through in an upward direction so that water introduced into the water inlet pipe flows into an upper portion inside the housing and exchanges heat with the sheath heater.

The present invention provides a hot-water supply device comprising: a flow control valve for controlling the flow rate of water supplied from the outside; a heating module for heating water passed through the flow control valve and guided thereto; a hot-water discharge valve for opening or closing a channel through which the water heated by the heating module is discharged; an input unit for receiving a hot-water discharge signal; and a controller for controlling the flow control valve, the heating module, and hot-water discharge valve such that the flow rate of water supplied to the heating module is controlled step by step by the flow control valve according to signals received by the input unit.