Can't remember exactly on the red nut. 10, or 11, or 12. I have my pins set a little squirely. I have five or six pins in the timer- each as a single and spreadout equally. Around 7 minutes maybe between each pin- maybe. So they run 15 seconds. On a 70 degree fall day with no wind- it maintains 1-1.5 inches of hot red coals straight across the stocker bed and the rest was ash. Tweeked perfect. Would run all summer like that. Tried four pins- would go out in the summer or warm spring- fall day without heat calls. Should I turn the nut up in colder weather. I don't know? It does not run all the time. I was ramming coal when I went to bed last with three zones pulling and five were pulling when I got up. Did It ever stop? I don't know. House is 70 degrees and Mamma Bear ain't complaining about being cold. Windy- temp was Zero. Should I adjust my red nut? Not if I don't need the heat. Maybe I'm wrong but I don't have to change a single setting regardless of outside temp and have no high limits. In the spring or fall I have opened the "window thermastat" on rare occasions. An yes, Stoyell's coal has always burned hot over the last four seasons. Keep track of that leak and fix in off season. Warrantee work if you can get it. The coal I had the last two years from Stoyell would klinker pretty good and hang off the end of the stoker bed occasionally. I developed a habit of checking it twice a day, taking a small stoking shovel from a fireplace set and knocking the entire ash into the pan. It kept it going. Plus I could see the coal fire twice a day and sneak an adult beverage from the basement fridge if I felt it necessary.
Check the stoker plates to make sure there is nothing interrupting the flow.