I've had an Oslo F 500 for a few years and have never been able to get good draft or heat from it. I know we're not suppose to leave ash pit door open to start stove, but I have to at times to get fire to start burning. I have a 25 to 30 foot 9"x12" flue chimney with only one elbow from metal 6" pipe going through the hearth wall. I had to run the wood stove into the same flue which has my cold start oil furnace in the basement below my woodstove. I noticed that this coldstart has a damper in its exhaust pipe that stays partially open... Could this be possibly interfering with good draft. When I open the ash pit door on wood stove it draws like a jet engine. .. Very disappointed with this stove. My wood is very well seasoned hardwood.