Overfireinthehole
Minister of Fire
If taking it outside and blowing it out doesn’t do the trick then I’d say you’ve got a broken weld somewhere in the back exhaust passages that you can’t get to so some of the air that should be coming through the firepot is being sucked in somewhere else instead. I’ve seen a few stoves like that where no matter what you do to it or where you try to run the stove ( inside or outside) the flame just continues to burn lazy and dirty because your not getting as much airflow through the pot since the combustion blower is sucking air through other holes. If you find a spot on the outside back of the firebox with smoke stains then that’s probably where your leaking but more than likely it will be somewhere you can’t really access without cutting off your external heat shields. Believe it or not, pellet stoves don’t last forever.