| 摘要 |
PURPOSE:To make it possible to fill hot water precisely to a set water level by a method wherein a filling flow rate per unit time in an initial stage of operation is used and when the flow rate is equal to or larger than a certain flow rate, sensing of inflection point is utilized, and when the flow rate is smaller than the certain flow rate, circulation judgement is repeated to decide a water level wherein make-up firing circulation is possible. CONSTITUTION:When a flow rate per unit time is equal to or larger than a certain value, two-side transfer is finished, and while one-side transfer, wherein filling hot-water into a bathtub is performed through a bathtub return pipe 21, bathtub feed pipe 22, and an inner-side pipe 11b of a bathtub circulation fitting 11, is being performed, sensed output of a bathtub water level sensor 52 is monitored by a controller 60 to sense a point of inflection. And a certain amount of water is filled into a bathtub 10 by two-side transfer so that the water level reaches a water level H which exceeds slightly a hole of the fitting 11. When a flow rate per unit time does not reach the certain value, the controller 60, after completion of the two-side transfer, changes over a three-way valve 51 to decide whether or not bathtub water circulates through a circulation circuit 20. As a result, hot water can be filled precisely to a set water level. |
