MrP57 wrote:How often do you have to replace these motors, and what else would be a good idea to have on stock?
Well, my stove is at least 10 years old, and I believe all the motors were original. The combustion blower was shot, it just screeched. The convection blower is still in good shape for another year or two, and I replaced the direct vent motor due to bearing noise, but otherwise it worked fine - it probably would have rattled along for several more years and drove me nuts. Stoker motor is original, but getting tired. I'd guess a few more years on that one at best.
I'll quantify my motor situation with the statement that I don't believe any of the motors were EVER lubricated since new (nor was the stove ever cleaned out - but that's another story). So, that should tell you how long motors should last, and if lubricated at least once a season, they will last a long time indeed.