OK, I'm not getting any initial pilot gas to ignite. The inducer motor activates, the vacuum switch works as the ignitor comes on fine. Check and cleared the pilot tube... no problem there. Get this..HVAC guy comes down to check it. He replaces the ignitor but his doesn't work. Mine tests out OK so he reinstalls it & "viola" everything works. It gets so warm in the house that my lovely bride turns down the heat at the thermostat and nothing after that. Right back to the initial problem. One more angle..power comes into the furnace via an old fused switch panel that in the past if the furnance went out you could switch the handle back and forth and the furnace would restart, could it be enough variation of amps going through the old panel that it would effect the gas valve??