hi all.came home yesterday to see my pellet stove had shut down and a very strong smokey smell in the house.i started it up again to see what would happen.it started right up and all seemed to be fine until i noticed the top auger had stopped turning.i shut it down and cleaned out the hopper only to find that the fire from the burnpot had somehow backed up into the stove and some of the pellets in the hopper had actually ignited.while cleaning out the hopper i noticed some foreign material and come to find out the block bearing gasket had melted.i took both assemblies out and the upper and lower gaskets are junk but the upper is far worse than the lower.my question i guess is what would cause the fire to back up in the first place.its an Englander 25 pdv 2006