In coal country the savings compared to heating oil is REALLY impressive. The basement will be warm and dry also. If you find that the basement gets too warm, insulating the boiler will help. I prefer to run them without jackets if the basement is large and/or uninsulated, but that is personal preference.
Phil May wrote:The air is a little more judgment than science. These things aint rockets dont get to worked up over settings.
The biggest thing to remember is that air blown through ashes does nothing but steal heat from the boiler. In my opinion, the fire should be roughly the same size as the burn plates (grates with air holes in them), but only after a long burn that allows the fire to stabilize...this is usually 30 minutes or so depending on how high the feed is set. You should not have burning coal on the solid ring around the pot. If you change suppliers of coal, it is good to check on the fire a few times after the change and see if any adjustments are required. If the fire starts to look lazy or creep onto the ring around the pot, and you haven't changed anything...it is probably time to brush out the boiler and check/clean the flue pipe.
Here are two pictures of a S-20 stoker (little brother to yours, but all I have pictures of) The first one is a good example of not enough air, the second is an example of too much air.
A few more questions for Brian. Have you checked the draft at the flue outlet? Are side panels on the base sealed? Boiler sealed to the base?
You should have a barometric draft control on the flue pipe, and a ballpark setting is enough to get started...but ideally a draft gauge is used to adjust the draft once you have the feed and air set where you want it. Like Phil said, it isn't rocket science...but having the air and draft set correctly will maximize the efficiency of the unit. 5-10% efficiency isn't a big deal to someone that burns 3 tons per year, but at 20 tons it is noticeable.