Question: Santa sort of plopped a new Harmon TLC-2000 wood/coal stove in the basement at the end of a tight 6" squeeze down a long factory built steel chimney for Christmas this year. Amazing! Anyway, I have a long ton of antracite stacked up ready to challenge the rest of Ole Man Winter for this season. A couple initial firings have gone well empiracally keeping the stack temp 400-600 *F. The Manual is clear otherwise but limits the description of "overfiring" to metal glowing red, which seems obvious and we know stove metal does this at about 900 *F. Just how hot can I burn this new coal black baby? Any different signs or symptoms for overfiring compared to its all wood burning cousins? On the other end, any concerns with restricting air to burn cooler since creosote is not an issue? Answer: No problem turning it down, especially with an insulated chimney. The only thing you have to be careful of is chimney reversal from not enough heat going up. A barometric damper should help with this. The baro will also help with eliminating the possibility of overfiring it. The stove should be properly designed not to overfire as long as the ash door remains closed. Although a very thin piece of metal might start to glow at 900 degrees, the thicker metal used in your stove probably means that it would have to hit at least 950 for a visible red to be seen. Again, proper stove design should make this difficult to do. I'd worry more about top (single wall) temps than the flue temps. Keeping it from 400 to 750 on these surfaces.