| 摘要 |
PURPOSE:To prevent improper ignition while maintaining fail safe even if a component is troubled by executing plural times a prepurging operation and an ignition trying operation in a fuel valve and an igniter, and stopping an igniting operation if a flame is not detected. CONSTITUTION:When a heat request controller 11 is turned ON, a fan motor 13 starts operating to escape remaining gas. When a prepurging timing is finished, a first fuel valve 7 is opened to supply fuel gas to a combustion chamber, and an igniter 10 is operated concurrently. In such a state, when a burner is ignited to generate a flame signal, large combustion of fuel is started. On the other hand, if a flame is not generated even if prepurging and igniting trial times arrive at set times, the igniting operation is stopped, an alarm unit 16 is operated to inform impossible ignition to an operator. Accordingly, even after, for example, a long pause of the burner, ignition and combustion can be automatically executed safely and effectively while maintaining fail safe properties. |
