I have a Janitrol GPD-075D which was installed in October, 1999 (no choice, it was a home warranty company deal, I could have $700 or they'd supply the furnace and pay the labor). In about a year, the flame sensor corroded (spontaneous burner cutoff, usually when the blower motor kicked on) and it cost $85 (labor) for the replacement (the repair guy swore it was bad). Less than a year later, it happened again, but since my guess about the first failure was right, I cleaned it myself rather than pay $85+ again for 20-30 minutes labor (anyone got any tricks for easily removing/reinstalling the thing?). Again, in well under a year, the sensor corroded again. Again, I cleaned it. About 6 months later, it happened again, so I ran a wire from its mounting screw to another screw on the plate in front of it. It worked more reliably for several months, but then started failing again. Nobody's heard anything about a recall or class action lawsuit over this have they? It has to be one of the worst designs I've ever seen - yeah, let's use a single signal lead and ground it where it's guaranteed to corrode! Is there some kind of non-corrosive gel that could be used to prevent this problem?
Had another surprise last night - got home from work to find the ignitor dead. Different repair place, this time $128 LABOR to replace the ignitor under warranty (and this guy charged for time to run out and get the part!). He also informed us that the ingitors usually don't last much more than 3 years. Interesting that they'd warranty such a part for 5 years!
I guarantee I will never buy any Goodman/Janitrol products again, and I'm seriously thinking home warranty plans (HMS, etc.) are a major ripoff (since they replaced the furnace, it is no longer even covered by them, and they replaced it with a piece of junk).
I suppose I ought to go out on the web and order a spare ignitor and flame sensor since I can get both together for well under the least labor I was charged. It's just such a pain getting to the screws to remove the parts in order to clean or replace them.
At least I know I'm not the only one having these problems.