What do you make of this build up in my stove pipe? This is the second time this season I've had to take things apart to clean them up. This was after about 2-3 weeks of moderate burning. This is single wall pipe. The damper you see is about 20" straight up from the stove. The build up brushes right off very easily. It gets to the point where I am not able to close the damper as much as I would like because I get smoke smell. I monitor the flue temp with a probe just below the damper and it is never below 500 during an active burn. The stove is an nc30 and the wood is 3-4 year old mostly spruce with some pine and small amounts of red maple.
More seriously though, it just looks like ash that has for some reason stuck to the pipe and damper.. maybe you are getting a complete burn but the pipes are catching the ash due to condensation of the H2O byproduct of the burn... just a guess...
Maybe air disruption at the damper plate? I just installed one this season and maybe I need to take a look.
That does not look like creosote, or at least not like stage- 3 creosote. Looks like you are burning hot and clean but there is a lot of debris going up the pipe. Maybe you are burning hard enough to send a fair amount of solids up the pipe with the exhaust? Or maybe that is just a by- product of burning soft wood? I have never burned any soft wood in the stove, other than lumber scraps, and so have no idea how the stuff acts. Hopefully someone will chime in here with better comments; I am curious about this myself because while I do not believe that is anything that could cause a chimney fire (too dry, at least the stuff in the photo) but that is a lot of build up for a couple of months or less of burning I think. Brian
Looks like a nice dry soot/fly ash build up to me...you must have a clean burning stove and dry wood. BTW, that stuff won't burn, so no danger of that...but yeah if you have to clean that damper all the time that would be a PITA. Once things build up on the damper you just don't need to close it as far...might be easier to adjust to a "new normal" than to clean all the time...just a thought
That's what I thought too, just surprised how much ash was being sucked out. I think it's ok, IR gun temp on the outside of the pipe is a little over half the probe value Yes, Just after the damper is a 90 and then a 2 ft horizontal run to a masonry chimney, there is some buildup in the 90 and the horizontal but not nearly as much. Yep, doesn't look like creosote at all, just really surprised at how much accumulation there is in such a short time. This is what happens until I can let the stove go out and clean things up, definitely a pain to do it so often. My seat of the pants feeling is that the stove runs better when the pipe and damper are clean.
Does your 30 act like it needs a pipe damper? I thought they are controlled with the primary air control well enough? Just curious. Looks like it would be a bit of a mess at clean up time!
I've got a ton of draft, 35 ft of chimney, so yes I find it easier to control the stove with a damper, probably could control the stove ok without one but I think it helps. The stove is on outside air too, so it breaths easily, my house is tight.
Maybe if you focus less on the angle of the damper and more on an estimate of the cross sectional area that is available for exhaust gasses it’ll allow you to run the stove longer between cleaning the damper/pipe. So when it’s fresh and clean, you will be closing it more (closer to horizontal), but as time goes on, the airflow will be partially obstructed by the ash, so you won’t need to close the damper quite as much due to already slowed exhaust flow... on super cold days you will close it more than the warmer days.. I have to think, if you’re getting smoke in the house, you’re essentially cutting off the exhaust flow too much and you just need to recalibrate the desired angle of your damper plate... I’d be curious to see if you get the same buildup burning different kinds of wood... if you’re running with an OAK, humidity certainly shouldn’t be a factor...I’ll certainly be watching this thread...
Tapping a stick of kindling on the outside of the pipe might knock that stuff loose without having to take things apart.
Stick a mirror in the thimble and look up to the top of the chimney if you can. How's does everything look in there. Perhaps cracked flue tile, cold air sneaking in somewhere? The only things that would cause build-up like that are wet wood, cold chimney temp, & air leaks. Have you had any back draft issues? Check for partial blockage as well. Birds nests, etc That is way too much build-up for 2 to 3 weeks. Something is causing this.....
