| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a heater capable of suppressing electricity rate and using sufficient hot water without requiring the labor of a user by automatically additionally boiling up water in a time zone in which a large amount of hot water is used at low electric rate as much as possible even when the new menu of an electric rate system is employed. SOLUTION: Firstly, when current time enters a daytime zone, it is decided that the current time is located in a first daytime zone (step S1) to prohibit the supply of current to an upper heater 34 and a lower heater 33 (step S6). Then, when the current time enters a second daytime zone from the first daytime zone, it is decided that the current time is located in the second daytime zone (step S2). When the amount of remaining hot water is less than 100 liters (step S3), the current is supplied to the lower heater 33 to boil up water of 370 liters including the remaining hot water to high temperature of 90 deg.C (step S4). Thus, the sufficient hot water can be used by suppressing the electricity rate without the labor of the user.</p> |
