Creosote dripping from Flue Cap of Wood stove

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Greebe

ArboristSite Lurker
Joined
Oct 4, 2007
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Location
Nome, Alaska
Hey everyone I could really use some help!

So I installed a new Jotul F602 in my shop and have been having problems with liquid creosote dripping down the outside of the pipe above the roof line.

I installed all the pipe per the instructions, black pipe from the stove to the double wall insulated pipe that goes through the ceiling kit, and then more double wall insulated pipe all the way up to the cap. The roof pitch is 5/12 and the peak of the roof is 10 feet away so the chart said the pipe should extend 68 inches above the roof where it comes through, but as the pipe was 3ft sections I get closer to 7ft.

The creosote is condensing on the cap and dripping down the sides and onto the roof. I don't like this at all and need to find out what to do to remedy the problem. The creosote looks like a thin molasses.

Any help would be much appreciated.

Thanks,
Greebe
 
burn only dry seasoned wood and dont damper down for extended periods of time
the closer to the cap the cooler the pipe is going to be (especially if your exposed way high over the roof like that) and more likely the creosote will collect there every time ...i use triple wall stainless pipe without issue form what ive seen long tall pipe installs above the roof line often cause more trouble than they help
 
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burn only dry seasoned wood and dont damper down for extended periods of time
the closer to the cap the cooler the pipe is going to be (especially if your exposed way high over the roof like that) and more likely the creosote will collect there every time ...i use triple wall stainless pipe without issue form what ive seen long tall pipe installs above the roof line often cause more trouble than they help

+1. if your wood is a little too green, scrounge up some pallets to mix with your wood. That should help get the temps up and mitigate some of the creosote formation.
 
Run your stove hotter than you have been, big flames are your friend. If your wood isn't very dry then thats out of your control for this season so opening the damper more will help.
 
I would not think that is creosote. Its more likely just water vapor and some smoke particles condensing. It'll wash off in the spring or at worst leave some black marks on the roof. It happens here too, but only when its REALLY cold, like below 20. Your in Nome, I'm guessing its a lil colder than that.
 
I have the same problem as you, I do not run the stove hot enough thus it drips like you say. Mine has dripped so much that it is eating away at the galvanized flashing around the pipe. I had a choice of running the stove hotter which would heat me out of the house or take the cap off, I decided to take the cap off.
 
If you guys installed it with the crimped end at the top of the ends of the pipe it will drip on the outside. Flip the damn thing over.
 
Before I posted that I didn't see it was the cap you were talking about. Was thinking of the pipe itself. But who knows flip your cap may stop it too.
 
The black pipe from my stove up to the double wall pipe is a bigger diameter and seems to let more heat up to the double wall pipe. So far I have never had problems with condensation in my 10+ years of burning wood. Dont know if this would help yours or not. Like others have said, try to burn dry wood and burn a little hotter. Good luck.
 
what's happening is when the hot smoke and gasses hit the cooler cap, it will cling to it like a magnet. after a while, it builds up and slowly melts away.

running "cool" fires is usually the culprit.
 
Thank you guys for all the replies. Sorry about the slow response time. Don't get on the internet that much.

The wood I am using is not green but there was a small batch that I was using that did have higher moisture content as I just pulled it out of the forest. It was the only downed tree that I cut this year. Usually I try to cut dead standing, but things happen.

Plus like you guys say I think I have been burning to cold. I have been running it with the draft about half way open. I don not have a key damper in the pipe as the manufacturer (Jotul) told me not to when I emailed them.

I noticed that when I burn properly dry wood that I can turn the draft down without problems but when it is a little wet like that wood I have to keep it wide open to keep from making a lot of steam.

I think that johncinco maybe right. We got a short spell of rain this afternoon and it looks to be all washed off. That is a relief.

I will keep burning this batch hot I suppose. I was just worried about over firing the little Jotul F602, but I bet that I have been way below the proper temp. I need to get one of those thermometer things for the pipe.

Thanks a lot,
Greebe
 
Yes a thermometer for the pipe should help alot. We have one on our stove pipe and it helps to find the best heat range to burn at. Good idea.
 
As others have said, temperature inversion. Warm smoky air hitting cold steel = condenstaion. Your cap compounds the problem. I take mine off when I start the stove in the Fall and replace when I shut it down in the Spring.

Even without a cap a little will still gather at the top. If a real hard wind is going sometime it will get soem on the backside of the stack. My wood has been in dry storage for up to 8 years and I still get it. Personally I would think hotter stack temp would make it worse.
 
As others have said, temperature inversion. Warm smoky air hitting cold steel = condenstaion. Your cap compounds the problem. I take mine off when I start the stove in the Fall and replace when I shut it down in the Spring.

Even without a cap a little will still gather at the top. If a real hard wind is going sometime it will get soem on the backside of the stack. My wood has been in dry storage for up to 8 years and I still get it. Personally I would think hotter stack temp would make it worse.

amen. i never had a problem with creosote until i added a cap to my chimney. now it builds up under the cap into a hard tar. it doesn't do that to the clay tiles...just on the stainless steel cap.

we added a screen to the cap (my son made the cap for me) but the screen got so clogged i ripped it out of there.
 
When getting a thermometer, Get one that you drill a hole in to the pipe and a probe will be inserted into the hole . They are much more accurate than the magnetic ones that just stick on the outside of the pipe. The one that I have is made buy Condar wood products.

Beefie
 
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