WATER HEATER

PURPOSE: To improve the hot water supplying characteristics at the time of starting a wind speed sensor. CONSTITUTION: This water heater comprises a wind speed sensor 12, a sensor temperature detector 15, a wind speed calculating selector 17 for selecting a wind speed calculator, a sensor power source control means 18 for applying a current, a constant temperature time calculator 19, a constant current time calculator 20 for calculating wind speed from the output of a time temperature change calculator 16, a heat exchanger 27, and combustion amount setting means 24. When the selector 17 selects the calculator 20 from the temperature of the sensor 12 detected by the detector 15, the calculator 20 predicts the actual wind speed from the time temperature change of the sensor 12 calculated by the calculator 16. The means 24 sets the combustion amount to the request combustion amount of the exchanger 27.