Unscrew and remove two hexagon plain nuts (15), two internal
Hexagon plain nuts (15)
tooth lock washers (16), and two machine screws (17).
Internal tooth lock
Machine screws (17)
Lift out spark arrester assembly (18).
Remove cover plate (if not already removed) to access the
flame thermostatic switch (19).
Disconnect electrical wiring from flame thermostatic switch.
Unscrew and remove flame thermostatic switch (19).
Scrape excessive soot from inside combustor area walls. Clean soot from
combustor parts with dry cleaning solvent and a small brush. Be sure to
wear protective gloves when using dry cleaning solvent.