Have you checked the basics of the chimney, since it has never been used, that is, making sure it is clear, cleanout door is in place and snug, and there are no uncapped flue openings into it from an upper floor? Seems like with a 33-foot chimney you should have enough draft to suck pieces of coal up the flue, let alone combustion gases. Is it an inside chimney that will naturally stay warm, or is it built outside where it is constantly chilled by the air? It's conceivable that on a warm day, with a low fire and an outside chimney on the cold shady side of a house, the flue gases could be chilled enough to drop your draft to almost nothing as you are seeing. Remember that draft is produced by the difference in temperature between the flue gases and the ambient air temperature.
P.S. I have read that, as a rule, you shouldn't start a coal stove until temperatures will be under 55 degrees all day long. That's obviously not entirely true, because some people run coal boilers all summer long to heat domestic hot water. But again, the point is that your flue gases must exceed ambient temps by some minimum amount in order for the convection effect to make sufficient draft. It sounds like you will be OK when Winter really gets here.
Last edited by rberq
on Sun Oct 05, 2008 7:21 pm, edited 1 time in total.