Safety mechanism for gas water heater without pilot light - has manually resettable electromagnetic valve shutting off supply if electrical power to extractor fan fails

摘要

The safety mechanism includes a gas valve (1) which may be manually reset, fitted between the gas supply and appliance. The valve includes a magnetically operated stop device (13) which is normally connected to an electrical supply. Connection to the device is via a switch (22) associated with the fume extractor fan (19) which withdraws gas fumes. The circuit also includes a fuse element fitted (17) near to the gas burner. If the fan is not operating, or the fuse is blown, then the supply to the valve is interrupted and it closes. It must then be manually reset (10).