| 摘要 |
PURPOSE:To utilize the heating ability at the maximum to quicken the boil-up time when the supply water temperature is high and to draw the hot water supply ability at the maximum when hot water is supplied, by carrying out the control of the flow quantity of a circulating pump so that the boil-up temperature in the heating unit becomes substantially constant. CONSTITUTION:A controller 19 compares a set temperature Ts of a temperature setter 18 with a detected temperature Ti of a temperature detector 16. When Ti is lower than Ts, a circulating pump 7 is actuated. Further, the controller 19 compares the detected temperature T0 of a temperature detector 17 with the set temperature Ts, the circulating flow quantity of the circulating pump 7 is determined so that T0 becomes equal to Ts. Hence, hot water returned to a hot water storage tank 1 is substantially kept at a temperature in the vicinity of a set temperature. In this manner, the flow quantity of the circulating pump 7 is adjusted so that the temperature of water on the outlet side of a heating unit is substantially constant. Therefore, when the temperature of water on the inlet side of the heating unit 10 is high, the circulating flow quantity of the circulating pump 7 can be increased and the boil-up time can be shortened. Further, during the hot water supply, the heating ability of the heating unit 10 can be utilized at maximum and the hot water supply ability can be drawn out sufficiently. |
