I tried to help a friend with his rofftop heating. This is spark ignition system: ribbon pilot ignites, flame sensor senses pilot, ignition module sends 24vac to main terminal on Honeywell GV but no main gas out! So I replace Gas valve but still- no good.Any toughts? There is 9" w.c. suply to GV
Last edited by keymanoman; 11-22-2010 at 12:15 AM.