We've been burning 24/7 for about 7 months now, our only source of heat, been going very well, thanks to all on this forum for help getting us this far, it's been invaluable.
In our TLC 2000, a recent phenomena has occured the past two days, after the morning shake prior to reloading - almost instant puffback conditions are created (churning smoke, etc) from the residual coal left over from the evening before. This has actually resulted in modest puffbacks on both days. We damper overnight the same, we do the morning shake the same as we have for months, nothing in our routine has changed. I have a suspicion that I need to sweep the chimney (6" SS Liner & Stove Pipe, 24' Run). The evening outside temps are averaging around 15-20F.