'Flame Proving'.....
When main flame lights off a milliamp signal is generated ---Flame Ionization/Rectification
That signal must return to circuit board to prove main flame is lit......no raw fuel flowing
No signal---circuit board drops DC to gas valve solenoid
Spark electrode is used for return path
Spark electrode gap 1/8"
Spark electrode engulfed in main flame
Spark electrode clean of soot/carbon ---clean with some emery cloth
Spark electrode high tension wore connectors CLEAN/TIGHT
Spark electrode ceramic insulator no cracks
Doesn't take much resistance to stop that milliamp signal.
