| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a water heater for avoiding shortage of hot water, and reducing running cost by restraining a hot water excessive state for a long period. <P>SOLUTION: This water heater has a hot water storage tank 3 and a heating source. A hot water quantity level of a plurality of classes is determined according to a required hot water heat quantity of one day, and the heating source operates for supplying a hot water heat quantity according to the selected hot water quantity level to the hot water storage tank 3. When a shortage is caused in the hot water heat quantity, the hot water quantity level is raised according to the next time hot water heat quantity, and when an excessive state of the hot water heat quantity is continued over a determining period, hot water quantity level optimizing control is performed for lowering the hot water quantity level. The jot water quantity level optimizing control is made different between operation time of an initial stage after installing the water heater and ordinary operation time after the initial stage. <P>COPYRIGHT: (C)2004,JPO</p> |
