| 摘要 |
PURPOSE:To prevent the generation of unburnt gas as well as large igniting sound, by shifting fire from a first gas burner block to a second gas burner block before reducing the pressure of the gas. CONSTITUTION:A control unit 18 is operated by the signal of a water amount sensor 4 to operate an ignitor 11. On the other hand, a gas pressure proportional control valve 7 is opened by the control unit 18 during the operation of the ignitor 11 while a gas valve circuit 16 is operated by the signal of a valve opening degree detecting circuit 15, which has detected the opening of the proportional control valve 7, to open a gas solenoid valve 6. When gas flows through the first and second gas burner blocks 5a, 5b and the first gas burner block 5a is ignited by the ignitor 11, fire is shifted to the second gas burner block 5b. Then, water in a heat exchanger 2 is heated, a delivered hot-water temperature sensor 8 detects the temperature of the water to control a delivered hot-water temperature setter 1 and the amount of gas is regulated by the gas pressure proportional control valve 7. |
