| 摘要 |
PURPOSE:To allow heating load to prevent boil in at least a heat exchanger part at the time of operation start by burning and controlling the device by specified middle heating power in which a burner is predetermined when the outlet side hot water temperature of a heat exchanger reaches a predetermined set temperature at which the burner is burned by maximum heating power after operation start. CONSTITUTION:When operation start actuation is performed by the actuation of an operation switch 35 of a main remote controller 34, a control circuit 33 actuates a circulation pump 6 while an electromagnetic open and close valve 30 and the like are opened to make a gas burner 4 strong combustion (for example, 20000kcal/h) to supply a thermal valve 20 with electricity so as to begin to open it. When the outlet temperature of a heat exchanger 3 by the detection of a high temperature detector 26 from operation start reaches, for instance, 80 deg.C, a proportional valve 31 is controlled to burn and control the heating power of the gas burner 4 by intermediate heating power (for instance, 9000kcal/h) between the heating power at the time of the strong combustion and the heating power at the time of weak combustion (for instance, 3600kcal/h). Thereby, boil in the inside of a heat exchanger in the case where load at the time of operation start is comparatively small can be prevented. |
