House filled up with smoke

My Quadra-fire cb1200 freestanding stove started letting smoke in the house. I planned on cleaning the stove, so I shut it off and went about doing other things while the stove shut down and cooled. I was upstairs and all of sudden I smelled smoke and you could see it. I keep this stove very clean all the time. After it shut down I opened the door and I noticed smoke still coming out of the burn pot even though the unit has been shut down a while. What would have caused this? I'm suppose to go out tonight and I don't feel like I trust it. Also, the burn pot was just cleaned out yesterday. Thanks for your help.

Its vented straight out and I don't have outside air. I plan on having it go straight up.

Did you switch it off and let it burn out or unplug it to let it burn out.

I swicthed it to off and was just waiting for the fans to shut off.

I would think that the exhaust blower did shut off, too soon for whatever reason.... I don't know the inner workings of the stove
I had the direct vent and never had smoke back after shutting it down properly the exhaust blower would run for about 45 minitues after shutting it down....
This is on a Harman though