| 摘要 |
PURPOSE:To surely shut off a fuel supply passage by providing a restraining mechanism which is switchable either to restraining mode in which the opening of a water pressure-responsive valve is restrained in response to the detection of water pressure by a water governor and to unrestraining mode. CONSTITUTION:When an on/off valve 13b of a restraining mechanism 13 is switched to the water delivery mode, a mode selector switch SW2 is opened to prohibit the electric current to the solenoid 9a of a safety 9 and an ignition circuit. When the main switch SW0 is pushed under this condition, the electric current is supplied only to the solenoid 3e of a water tap 3 to cause a pilot valve 3d to open to allow a water flow to a water governor 4. Part of water passing through the upstream chamber 4a of the water governor 4 is guided to the downstream chamber 4d via a bypass passage 13a and a passage 4c to prohibit the displacement of a diaphragm 4e toward a water pressure- responsive valve 10, holding the water pressure-responsive valve 10 in the closed state. As a result, the fuel supply passage 8 to a burner 7 is surely shut off by the two of the safety valve 9 and the water pressure-responsive valve 10. |
