I have had my stove for 6 Years and I burn between 4 to 6 Ton's a year though it and I use it to heat around 2,600 Sqft all winter long in NY. I usually Vacumm it out every 5 days and twice a season I remove the Exhaust fan and clean out all of the sides and exhaust ( I do the side covers every 2 to 3 weeks )I can tell when the stove is starting to get dirty by the way it burns. I did add a extension on my burn pot middle of last season and the burn pot now stays clean and I get no more missed pellets. I used to have to clean the stove a lot more and I would have a bunch of smoldering pellets all over the place.