What component senses the flame to prove ignition?

The component responsible for sensing the flame to prove ignition is known as a flame sensor. Flame sensors are crucial in gas appliances because they ensure that there is an actual flame present before allowing the gas valve to remain open and supply fuel. If the flame sensor does not detect a flame, it communicates this back to the system, which can shut off the gas supply to prevent hazardous situations, such as gas leaks or fire hazards.

While igniters are essential for initiating the flame, primarily by creating a spark or heat source, they do not provide feedback on whether the flame has actually ignited and is stable. The ignition module may play a role in managing the ignition process but does not directly sense the flame. Other components like the gas valve and pressure regulator serve different functions, like controlling gas flow and regulating gas pressure, respectively, but they lack the ability to confirm flame presence. Thus, the correct choice emphasizes the specific task of flame sensing, highlighting its importance in safe gas appliance operation.