Which of the following are NOT located on a combination gas valve?

The correct answer identifies the spark igniter and sensor wire as not being located on a combination gas valve. A combination gas valve primarily manages the flow of gas to the burner and includes components like a gas pressure regulator and a manual shut-off valve, which are essential for safe and efficient operation.

The combination gas valve typically integrates a gas control valve with safety and operational features but does not include the spark igniter itself. The spark igniter is usually a separate component located elsewhere in the heating system, designed to generate a spark to ignite the gas-air mixture at the burner. Its function is critical but is distinct from the gas control and regulation functions performed by the combination gas valve.