What component ignites the pilot in intermittent pilot systems?

In intermittent pilot systems, the hot surface igniter is the component responsible for igniting the pilot flame. This igniter is usually made from materials that can heat up quickly, such as silicon carbide or silicon nitride. When an electrical current passes through the igniter, it becomes hot and can ignite the gas flowing to the pilot.

Once the pilot flame is established, it can be used to light the main burner when required. The use of a hot surface igniter is effective because it provides a reliable means of starting the combustion process without the need for a continuous pilot flame, thus enhancing the efficiency of the system.

Other components like flame sensors, thermocouples, and ignition transformers play different roles in the gas ignition and control processes but do not ignite the pilot flame in this specific system. Flame sensors detect the presence of a flame to ensure safe operation, thermocouples measure temperature and can act as safety devices, and ignition transformers provide high-voltage spark for igniting the gas in systems that use direct ignition rather than a pilot flame.