Thermostats with flame failure device

In the thermostats with a flame failure device – electromagnet and thermocouple – once the control spindle has been pressed completely, and a few seconds after the burner has been lit, the thermocouple, swept by the heat of the flame, generates a current sufficient to activate the electromagnet, thus allowing the flow of the gas.

At this point, the control spindle of the thermostat can be released. If the flame accidentally goes out, the thermocouple cools down with a consequent reduction in the current which causes, after a few seconds, the electromagnet to close, interrupting the flow of gas.