I managed to get my Quad Santa Fe roaring tonight, maybe the third time in a year, (after putting four ton of pellets through the little darling.) Anyhow, I had dumped the firepot when I got home from work and everything was cool, but an hour later it started to rumble big time, serious vibration noise and all. I shut down the thermostat and once I was satisfied it HAD shut down I went off to the dog training club for a couple hours to let things cool off. On my return I set out to clean the stove and immediately found the problem - clinkers had formed a bridge in the firepot, so pulling the dump rod didn't do the job, I had to stir it up a little bit with a screwdriver and then dump it. This happened once or twice last year, different pellets, its just a thing that can occur. Pulling that rod on the Quads is really easy but every once in awhile its not 100% effective. No big deal, just do a visual inspection to make sure the crud gets cleaned out.