We had the furnace in our older mobile home replaced with a complicated Coleman. It worked OK for awhile. Then it would ignite, burn and blow for a couple of minutes then go out. The control box would flash once which meant failure to ignite according to the sticker. But it would ignite, then go out. We had it looked at by the sellers tech. He could not figure out the problem and every time he came out he changed another part until I doubt that there is a single original part left on that piece of....Of course the warranty expired before the problem was corrected. Any thoughts on what the problem might be and what to do about it?????
I've had similar issues with my furnace, although it's a completely different brand. It always ends up being a dirty flame sensor. I just clean it off with some steel wool/ sandpaper and it works fine for another 3-4 years. I'd check that first.