I have a Jotul Oslo that I have been burning for 3 seasons with no problems. The last two times I tried to start a new fire, all I got was smoke pouring out and no draft at all. I checked the whole chimney and it looks perfect. I looked for a troubleshooting section in the owner's manual and there is none. Is there something in the top of the stove firebox that I need to clean out? The air supply and ash pan are both completely cleared out. Please help, as I can't keep filling my family room with smoke.