Resideo Q340A1082 30" Thermocouple 30mV

The Resideo Q340A1082 is a 30-inch thermocouple, a safety shutoff component crucial for gas-fired HVAC systems with pilot lights. It works by converting heat into a small electrical voltage (around 30 millivolts). Located near the pilot flame, the thermocouple's tip heats up, creating a temperature difference from its base. This difference generates a millivolt current that signals the gas control valve to stay open, allowing gas flow to the burner. If the pilot flame goes out, the thermocouple cools down, the voltage drops, and the gas control valve shuts off the gas supply as a safety measure. This 30-inch length offers compatibility with a variety of furnace and boiler applications.