PROBLEM TO BE SOLVED: To provide an electric instantaneous water heater system capable of safely controlling an electric power amount of a plurality of instantaneous water heaters, and excellent in energy saving effect.SOLUTION: Temperature sensors 11 and 21, flow sensors 12 and 22, and control devices 13 and 23 are provided in an instantaneous water heater 10 and a hot water storage type water heater 20. A control device 30 has electric power amount estimation means for estimating an amount of electric power consumed by one unit. The control device 30 has electric power amount calculating means for calculating a total amount of electric power consumption of all of the instantaneous water heaters 10 in operation. The control device 30 calculates the number of the instantaneous water heaters 10 simultaneously usable at present from an upper limit electric power amount. The control device 30 blocks power distribution to the hot water storage type water heater 20 when the number of the water heaters exceeds the
