I have a new Harman accentra insert. I have been burning Lignetics pellets in it for a little over a month. I have been scraping out the burn pot and cleaning it every 3-4 days. I've noticed that the auger has a low rumble sound to it on lower speeds and that the ashes seem to be clumpier than before. Is this normal? is it the pellets? or is something wrong with my settings/stove? Sorry for my ignorance, I am new to burning pellets.