With my sf250, I have the ash door knob open between 1-2 turns. 1 turn usually when outside temps are 20 degrees and up. Up to 2 full turns when temps approach zero. My 2 load door knobs are never open past 1/2 turn each. I usually set them at 1/4 turn each when my bottom knob is open 1 turn. I open them to 1/2 turn when my ash knob is open 2 full turns.
It all depends on how big your house is and how well insulated. The sf250 us a beast and puts out a lot of heat (too much for my house usually). That's why some here have put in firebox reducers (a way to make the coal bed smaller to make it run like a smaller stove).
I've been running mine for 4 years and have made my share if mistakes. Be sure to have a co detector on each floor of the house. Don't ever let new coal sit and smolder (especially when it gets warmer outside). That's where I get in trouble sometimes and make my co detectors go off.
Keep asking questions. Don't be afraid of the stove!