I'm not an HVAC tech., and I'm not asking how to repair my furnace. The ignitor for my 1998 Miller gas furnace has gone bad 4 times in 2 years. I've had the same service replace it every time. Two months ago another standard one went bad, and it was replaced with a nitride ignitor. The service tech said he didn't believe that one would ever go bad. But it did--yesterday--and the same tech came out and replaced it free-of-charge today. When I asked the tech why these keep burning out so fast, he shrugged his shoulders and said, "must just be a bad one in the bunch". I appreciate their service, but I'm not sure if they know what's causing my problem. Does anyone here have any ideas? Thanks.