Patent ID: 8662022

Claim:
A water heater comprising: a burner; 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 a water temperature in the hot-water discharging pipe; 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: a lapse of time from a previous operation is determined, and when the duration of time is greater than a predetermined amount of time, the operation control unit compares the detected temperature at the time of non-operation with the preset temperature; and when the detected temperature is lower than the preset temperature by a predetermined degree at the time of non-operation the water flow rate control unit reduces the flow rate of flowing water to a flow rate lower than a previously determined flow rate of flowing water, and performs the temperature control of discharged hot water at the time of starting of an operation with the reduced flow rate of flowing water.