Abstract: An instantaneous water heater with enhanced temperature control and less variation in output water temperature has an output hot water pipe extending into a heating tank through the top thereof and surrounded by a coiled sheath electric heater for heating the water in the tank, the output pipe extending to the tank bottom and provided with an inlet thereat. An inlet pipe for water to be heated extends into the bottom of the tank and is throttled to provide an accelerated flow of incoming water away from the heater and outlet pipe toward an overheat prevention thermostat mounted externally on the top of the tank and connected to the heater. An output hot water temperature sensor located within the output water pipe adjacent the inlet thereof cooperates with a control unit of regulating operation of the heater to maintain the hot water output temperature at a preset level.

Abstract: A compact and inexpensive hot-water washing apparatus for personal hygiene which is used for washing the anus or the like after depositing stool in a toilet. By the rotation of an operation shaft 41, the start switch 42 of a pump 27, a flow control valve 30 and an operating valve 35 interlock. The control of the flow rate of the hot water to be supplied to a nozzle 4 for washing the anus or the like and the use of an inexpensive non-self priming pump are enabled by providing a water passage through which the water sucked in from a low level cistern 6 is discharged into a hot-water tank 25 through the operating valve 35 by the pump 27, and a water passage for returning the hot water or water in the hot-water tank 25 through the flow control valve 30 to the suction port 34 of the pump 27. The action of a heat equalizing plate 52 prolongs the duration of hot water jetting of an optimum temperature.