To much smoke or ash

From Cornburning

I have a dovetec that i have been using as a secondary or third heat source for quite a few years. It regularly "smokes" through the holding area on the top . This year it seems every second bag or so fills the room with smoke. I can't figure out why. At first I thought it was too much dust which was building up in drop tube but after thorough cleaning it still smokes. The exhaust vent has lots of pressure out side when you stand beside it. I don't know what else I should do. The fire burns perfectly, and does everything it should.All fans appear to work fine as well .. Any hints!!!!!!!!!!!! Please...

My main source of heat is a Pelco corn Boiler and it has started giving me issues as well After running for a few hours it will blow its 30 amp and 100 amp breaker I cant see the reason for it. I know this is a little out of realm of most people on here as it is a 750 000 btu unit but just though .... maybe some one might have an idea.