What to do in case of a flue fire

[fbelec]

What is the crackling sound that you hear in the black pipe when the temp reads 500-600 degrees from the stove to masonry chimney? Is that creosote cracking off and burning or is that just the sound a hot fire makes in the chimney? Is that sound a good thing or bad? I've got a 20+ ft chimney.

Another question for a dummy, how is a masonry chimney measured, from the floor or from where the pipe is inserted into it from the stove?

One more, is it a bad thing for flames to go up the black pipe coming out of your stove/furnace?

that crackling noise is creosote heating up and burning. if you were to look at it when the noise is there it might not necessarily be flaming creosote but it would be glowing type of burn. if it were thick creosote you could also here it dropping from top to bottom of pipe when it loses it's battle with staying on the pipe

as far as the measurement of the masonry chimney i'm not sure. common sense tells me that it would be measured from where the connector pipe goes into the chimney because from that point up the chimney is heated and that is what makes the air in the chimney rise. but i guessing

as far as the flame going up the connector pipe, if you didn't have creosote in the chimney nothing could fire up but if you keep that going and you have some creosote in there that will set off the fire in the chimney.