Servicer tried to push it to Monday, but this was after they already had to delay the original scheduled appointment- by almost a week. So, I told them that, y'know, for having a thing leaking gas that we could've found out about a week ago, I think it'd be best if they came tomorrow.
So, they are. It's roughly $1000 (including installation, from what I'm being told), and I don't think the warranty will cover it- it's not a breakdown. God knows that getting poisoned on gas isn't worthy of a replacement on those merits. *shrug*
The things 12 and half years old, though, so I guess I can't ask too much more of it.