Yesterday I had a full occlusion of my pipe. I haven't even had it 2 months yet with 2 chimney fires, etc. I cleaned out the pipe and got the creosote tar off the bottom parts, also getting a big stick and whacking off the spark arrestor cap (it's pretty high up, too high and I couldn't get leverage enough to twist it off while looking straight down to the ground from way up there, so a big stick got the occluded screen right off). It was completely full of 3rd degree tar creosote already (that's after 2 fires).
It's kind of a no-win. The recirculate function, even when roaring at 600 degrees lets cool smoke out and my chimney is 28 feet up when the reburn is on. Too bad I can't get a shorter chimney or a thinner pipe to get it moving out faster. I got the triple wall pipe mainly to preserve the inside heat since it was going out and up.
I couldn't get the chimney sweep all the way into the top with that cap on it and with no footing or holding, I couldn't sweep it from the top or get that cap off. I was not terribly happy, so a big stick whacking that thing off from 30 feet up served many purposes this afternoon.
From now on, I'm going to get that fire roaring up the chimney once a day >600 degrees for at least a minute or two (I had been but not that hot, not that long). Inside the stove burns hot but the smoke from the top I suspect is too cool by the time it's out, leaving whatever particles exist by then to all stick to the spark arrestor cap.
It occluded yesterday and it took 24hrs to fix. It was a smelly mess and I'm happy it's over. I'll be happier when my house doesn't reek of smoke.
Although my stove has the secondary burn, blah, blah, blah, the rear temperature control vent is another culprit (actually we are, not an inanimate object). My wife or I likely adjusted it too low during the days when it was warm, causing buildup in no time at all given that double burn function seems to take a lot of heat out before releasing the smoke.
Just one day after cleaning the outside chimney (but not knowing the top cap was occluded still troubleshooting and cursing the day I was born), a fair amount of tar creosote formed again inside the pipe while I was troubleshooting this nightmare (dry wood, air vent closed, reburn off so 1/2 the smoke went directly out best I could make it, while the other 1/2 went directly out of my 2 basement windows).
Soon as I got back from work, the fire had gone down enough I could spray the rest out, took everything apart and was able to sweep out the top since the cap was off, showering myself with creosote balls. I need to get another cap that's high enough I can get the sweeper into from below. My stack is 3 1/2-4 feet above my roof straight up the side. Not safe standing, too high above a ladder and I can't get leverage if this one gets stuck. I'll need to find a cap I can put on and don't have to keep playing with it, where the screen doesn't occlude the entire pipe.
I don't recall letting the stove go below 300 (I haven't shut it down for over a month straight of burning, though). Just didn't have a good week...