Resideo Q340A1108 30mV Thermocouple 48 Inch

The Resideo Q340A1108 is a 48-inch thermocouple, a crucial safety device in gas-fired heating systems with standing pilots. It works by converting heat into a small electrical voltage (30 millivolts). The pilot flame heats the tip of the thermocouple, creating a temperature difference from the 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 extinguishes, the thermocouple cools down, the voltage drops, and the gas control valve shuts off the gas supply as a safety measure. This 48-inch thermocouple offers ample reach for various furnace and boiler installations. Its key specifications include a length of 48 inches (1219 mm), an open-circuit voltage output between 26 and 32 millivolts, a resistance of 0.03 ohms, and a weight of approximately 0.18 pounds.