G2 Gas Fitter Practice Exam

The primary function of a flame rod in a detection system is to provide flame sensing. A flame rod detects the presence of a flame by generating a small electrical signal when it is exposed to the infrared radiation emitted by a burning flame. This signal ensures that the burner is operating correctly and can trigger safety mechanisms in case the flame goes out or is not present when it should be. This functionality is crucial in maintaining safety protocols and efficient operation of heating systems.

The other options, while related to the broader context of gas systems, do not accurately describe the role of a flame rod. Heat distribution refers to how heat is spread throughout a system, thermal connection pertains to the relationship between different components regarding heat transfer, and gas flow regulation deals with controlling the amount of gas entering a system. None of these functions relate to the specific purpose of flame detection, which is why flame sensing is the correct answer.