| 摘要 |
PURPOSE:To eliminate a possibility of keeping a remaining hot water at a high temperature, provide a superior safety and perform an accurate detection of an amount of remaining hot water by a method wherein a hot water accumulated in a bath tub is heated, the amount of hot water is calculated from a heating time required for increasing the hot water up to a specified temperature and a hot water of which amount corresponds to a difference between the calculated amount of hot water and a predetermined amount is supplemented from a hot water feeder. CONSTITUTION:As a desired amount of hot water accumulated in a bath tub 2 is set in advance by a knob 29 for setting an amount of hot water fed into a bath and then a bath automatic switch 25 is turned on, a pump 9 is driven, a flow rate sensor 8 may measure an initial temperature of remaining hot water T1 by a temperature sensor 10 for detecting a desired flow rate, a fuel valve 43 is opened to cause a burner 42 to be ignited, and then the hot water is circulated and heated until the temperature of the bath hot water is increased by a specified temperature DELTAT. A heating time (t) is measured by a micro-computer stored in a control unit 22 and an amount of remained hot water Q at the present time is calculated from the heating time (t) required for increasing the remaining hot water and the calculated hot water amount Q are compared to each other and a three-way changing over valve 18 is changed over to decrease the lack amount of hot water from the hot water feeder 3 and then it is measured by a flow rate sensor 15. |
