Ignition controls and components connect to the various parts of a combustion appliance and start and manage the ignition sequence. Ignition gas valves open and close to control the flow of fuel in combustion heating systems. Ignition controls ensure that all furnace components operate in the correct order and at the right time. Ignitors create the spark or ignition source that lights the flame and starts the combustion process in furnaces and boilers. Flame sensors detect the presence of fire in the combustion section of a heating appliance and provide a sensor signal the controller uses to manage the combustion process. Pilot light assemblies install into heating appliances and create a small flame that ignites the primary burner. Thermocouples and thermopiles verify the presence of fire in the burner and send a signal to the control board to keep fuel flowing.