I DO NOT like high temps especially being a greenhorn but this was the last stage on my burn levels. Reached the big five 00 just now. The flue started popping around 475 but I held in reluctantly. All is well I think. I still wished I knew what a target temp as well as a max temp for a flue like mine would be. 6 inch 24 gauge pipe, clay lined chimney. House is 30 years old chimney is 3 weeks out of virgin status.