Teledyne Laars W0038001 Ignitor & Gasket kit, Mighty Therm LoNox

The igniter is a “glow bar” type silicon carbide unit. It is
energized whenever there is a call for heat and the red
"IGNITER" light on the boiler control is lit. After the igniter is
switched off and the boiler continues to run, the igniter functions
as a flame sensor for the boiler control.
If the ignitor fails and must be replaced, always install a new
igniter gasket with the replacement igniter.
CAUTION: Ignitor gets hot.