Go home from work and started a fire. Had some coals left from this afternoon. 2pcs of American Sycamore on the bottom. 2 pcs of Ash and 1 pc of Shagbark Hickory across the top and then a small pc of ash across that. Fire got going nice and quick and them for about 5 minutes it took off! Temp went to 600F REAL FAST! Then I got freaked out. Heard loud crackling in my stack towards the ceiling. Lasted about 10 minutes. Chocked the damper down to 3 and turned on the blower full blast. WHAT IN THE WORLD WAS THAT???? Never experienced that before. Did I do a no no??? Advise PLEASE.......