I have a new quad 1200i, lately I have been noticing alot of smoke upon startup. Today the burnpot filled about half full and tried to ignite, looked like a chimney fire and a big pop when it did start. Luckily I went to the stove when I seen the yard full of smoke and all I could do was turn the thermostat down. What causes so much pellets to drop at startup? I have been cleaning the burnpot, firebox everyday. Does pellet brands vary upon startup? I have been trying different brands. Anybody else with this problem?