Have a Furnace going through the start up cylce and does not ignite. Ignitor is getting hot, gas valve is opening, I can smell gas. It locks out after a few tries. Every once in a while it lights off and operates normally.
Checked the orfice by the ignitor,ran a paperclip into the whole to make sure it was not plugged. Did not help. The burner assembly on this furnace is a pain to get to.