This stove is 10-12 yrs old, it can burn coal, but I have never done it until now. It has an underfire draft adjustment, an overfire air adjustment and a draft adjustment on the very top part of the stove that goes to the flue. I can get a good coal fire going, using wood and then adding the coal. I then add more coal and all goes well. If I want to cut down on the heat output, I assume I can close back on the air adjustments. I have played with them and I end up with the fire going out due (I guess) to not enough air/draft. So, my question is how soon after making an air adjustment shoud I see/feel a difference in temp or flame? And what air should I be adjusting? I suspect that I am making too much of an adjustment, and it kills the fire. Is there any place on the web where I can see photos of a coal fire and how it should look?