| 摘要 |
<p>A boiler is provided with: a boiler body in which the water level inside water pipes when combustion by a burner is stopped is lower than the upper ends of the water pipes; water supply means; control means which controls the water supply means depending on the water level in the boiler body; header water level detection means which detects a water level existing inside an upper header; and a downcast pipe. The control means performs first control for controlling the water supply means so as to lower a boiler body water level when the water level detected by the header water level detection means reaches a header set water level and second control for controlling the water supply means so as to raise the boiler body water level when the amount of drop in the boiler body water level reaches a predetermined amount after the first control.</p> |
