Flame MUST engulf spark electrode when it lights off
Spark electrode needs to be clean-----emery/crocus cloth
Ceramic on spark electrode if cracked will allow ground tracking...wipe down using a rag with silicone sprayed on it
Contacts on high tension wire at board or electrode must be clean/tight
Flame has to 'prove' it lit
It does this by flame ionization which actually generates a millivolt signal that goes back to circuit board.if circuit board doesn't get this signal it shuts down gas valve