Patent ID: 8733297

Claim:
A water heater comprising: a burner connected with a gas supplying pipe; a heat exchanger connected with a water supplying pipe and a hot-water discharging pipe and heated by the burner; a water flow rate control unit provided at the water supplying pipe and controlling a flow rate of flowing water in the heat exchanger; a temperature detection unit for detecting water temperature in the hot-water discharging pipe; a gas pressure control unit provided in the gas supplying pipe to control a flow rate of gas supplied to the burner; and an operation control unit controlling a temperature of discharged hot water so that a detected temperature acquired by the temperature detection unit agrees with a preset temperature by control of combustion of the burner and an operation of the water flow rate control unit, wherein: the operation control unit compares the detected temperature with the preset temperature and when the detected temperature is lower than the preset temperature by a predetermined degree, the water flow rate control unit immediately reduces the flow rate of the flowing water from a previously determined flow rate of flowing water at a point of time that discharged hot water is required and then the gas pressure control unit immediately reduces the flow rate of gas according to the flow rate of flowing water; and the operation control unit performs the temperature control of the discharged hot water.