I have a Quadrafire Santa Fe. It is approx 10 years old. It ran fine for years, same pellets, same conditions. In fact, it runs fine now, when it runs. The problem is the feed auger. I have put 4 new motors in (2 OEM, 2 aftermarket, interestingly, motors were all labeled the same) , and now have to put another in, and I can't figure out what is going on. The stove will work fine for a few weeks to a couple months after replacement, but then stops working. The auger motor itself is fine, it is turning. The auger is not turning, at least not while under load. First reaction..."the fool did not tighten the set screw on the auger." Set screw is tight, auger is tight, the problem in each case has been in the gear box. I can pull the auger/motor assembly out of the stove, and unit works perfectly. But when it is under load (in stove, with pellets) it will not turn the auger. The motor is definitely turning, on these motors the armature shaft is visible at the top, and you are able to touch/see it turning. It will turn fine when no load, but if it is in the stove trying to move pellets, or I grab the auger with channel locks, or take the auger off and grab the gearbox output shaft, it will not turn, although the motor does. I have taken the gear box apart on a couple, on the theory that the gears were stripped. They were not. Apparently one of the gears is spinning on its shaft. Anyone else have a problem with the auger like this, or know how to fix it? I looked at the auger from every angle, metaphorically and physically, and can see no problem, such as the auger binding on the chute walls or striking the bottom of hopper. I even shortened the auger 1/4" on the possibility that pellets were binding the shaft against the bottom of the hopper, to no avail. This is a mystery to me, and I would appreciate any help. FWIW, I am a mechanic and worked in a stove shop on pellet stoves for a few years, so I have a pretty fair background on pellet stoves. I cannot imagine having 5 bad gearboxes, so my working theory is that there is something causing the auger to bind, which then loosens the gear on its shaft. But I will be darned if I can figure out how or why. Thoughts, anyone?