Yes, the gas valve is opening when the cover is on because I can smell it coming out the exhaust vent outside.
True, the ignitor wouldn't work with the cover removed if that were the culprit, but I'm just operating under the assumption that there is some defect in the wire that is not visible to the eye. Perhaps there is a small crack in the insulation that is shorting to the cover when it's on. I doubt it, but it's cheap and easy to replace, and plus, I don't know what else to check. No debris on the burner.
I called Suburban, and they said they don't even make the NT-12SE any more because it had problems lighting. But it sounded like that was more due to an inadequate amount of gas, as the NT-16 is the same exact unit except it has a higher BTU burner.
Dave
