| 摘要 |
PURPOSE:To prevent the temperature of room heating circulating hor water or the like from decrasing irrespective of the variation of the quantity of suppied hot water in a hot water supply room heater having an indirect heating type heat exchanger in a circulating hot water passage by employing as a reference set temperature value the value detecting the approximately intermediate hot water temperature of the heat exchanger. CONSTITUTION:A hot water supply room heater heats by burning gas fuel fed through a solenoid valve 10 and a proportional control valve 11 in a circulating room heating hot water heating heat exchanger 1 having a hot water supply heating coil 2. In this case, the temperature of the circulating room heating hot water is detected by a temperature censitive element 13, the signal of which is applied to a temperature detector 15, and the temperature signal from the detector 15 is in turn inputted to a comparator 17. The approximately intermediate hot water temperature of the heat exchanger 1 is detected by a temperature sensitive element 14, the signal of which is applied to a temperature setting unit 16, and a reference signal of the setting unit 16 is in turn inputted to the comparator 17. The comparator 17 thus compares both the signals to control a proportional control valve 11 with a comparison signal thereof, thereby proportionally controlling the quantity of supplied gas to a gas burner 12 and thus controlling the temperature of the room heating circulating hot water. |
