Creosote

[mmp]

We have burned wood in a Prairie Farm wood boiler for 37 years. It finally gave up the ghost and we changed to a Hearthstone Castleton wood stove. (In a walk-out basement). The ash clean out for when the chimney is cleaned is 4' up the wall, and since we put in the Castleton, liquid creosote has be running out of it and down the wall. We burn hardwood that is extremely dry - at least two years, cut & split and have NEVER had this happen in 37 years. Our chimney when cleaned (before) has only shown dry dust for a residue. Has anyone else had this problem? We suspect maybe the chimney doesn't cool down since the stove holds it's heat over night? Or maybe the smoke shelf (thank you EPA) causes it? Or??? We are ready to take the stove out. Please help!!

 

[tcassavaugh]

first, welcome. sorry to hear about your problem. i haven't had a liquid problem in ages and i don't remember what really caused it. i think i burned the stove hotter to warm things up in the chimney to fix it. in my opinion, sometimes those old smoke dragons worked better than the newer stoves. there is so much knowledge here that someone will have some suggestions i'm sure.

 

[mellow]

Every time I have seen issues of liquid creosote coming down the pipe it is either cap issues or wet wood or air leaking from that cleanout.

What is your usual burn procedure? How hot does the stovetop get and stove pipe before it goes through the thimble?

Can you show us some pictures of your setup?

 

[bholler]

Liquid creosote is almost always either from wet wood or a cold chimney. You old stove put allot more heat up the chimney than you new one. That means the smoke cools and the water condenses out. Describe your whole set up to us and we may be able to help

 

[BrotherBart]

Yeah we need to know all of it about the stove, the wood, where it is located in the house as well as how you are burning in it. That is a really small soapstone stove to be replacing a boiler in Wisconsin.

 

[mmp]

Yeah we need to know all of it about the stove, the wood, where it is located in the house as well as how you are burning in it. That is a really small soapstone stove to be replacing a boiler in Wisconsin.

OK - replying to all of the above. Hopefully, attached are pictures of our setup. The white pipe against the wall to the right is makeup-air, which comes right to the bottom of the stove. This was put in after the installers came out because we had such a hard time getting this stove started. They did too. We finally have it down.

Start with paper, cardboard, kindling, small pieces & then larger. It really doesn't want to burn if the outdoor temp is above 35 deg. This stove goes into the same chimney we used for our Prairie Farm wood boiler. We heated the house with that one boiler for 37 years. Yes, the same stove. It was hooked up to our gas/hot water heat system (the pipes can be seen above in one of the pictures of the soapstone stove. We decided to go to just a free-standing stove because our boiler-man retired, we still heat the shop only with wood, and just didn't want to cut as much wood. We live on 200 acres of oak/maple, and have burned our own wood for 40 years. My husband cuts, blocks, splits all the wood, and it is stacked outside, but with a roof over it. We never burn anything that hasn't been split for 2 years. We currently use the stove just to take the chill off the basement & save a little on gas.

There is a cap on the chimney. The stain on the outside of the chimney seems to be from the smoke, as it is not liquid. The temperature on the top of the stove is usually between 300 & 400 according to the thermometer on the stove. We're wondering if the smoke shelf keeps the chimney from getting hot enough. We have used two CSL logs this year.

We heat the shop with an Ashley wood heater (this is the second one since 1985).

 

[bholler]

What size is the clay liner in that chimney? Where is the cleanout in reference to the crock? Is that cleanout sealed? Are there open block cores inside that cleanout? How high is the chimney total? What are you pipe temps through out the burn?

 

[jatoxico]

I'm kind of ignorant on the wood boiler situation. Was the boiler sending hot water or air into the house (living space)? If so now the stove is just trying to send air up to the living space by convection. If that's the case those basement walls will suck up some heat for sure.

 

[mellow]

Can you open up that panel and show us a picture of the cleanout?

 

[maple1]

How dirty did your boiler used to get? Did it use to make a lot of creosote within the unit itself? Require a lot of cleaning?

That chimney doesn't look all that high - I suspect you might not have enough draft (I think you also mentioned the fire is hard to start?). That together with how cold it is is likely condensing the creosote & also might be affecting the quality of the burn itself. You also mentioned the stove holding heat well overnight - that also might be a sign that it is not burning hard enough to burn off the nasties within. i.e., might be choked down. And if the boiler used to get dirty, it might have been condensing a lot of the nasties before they got to the chimney.

Was the creosote there before the makeup air pipe thing was installed? It might be cooling things even more and causing more condensation.

I'm also not familiar with either that boiler or that stove so not 100% in what I'm saying.

EDIT: I'm also curious what it looks like inside the bottom of the chimney. I think I see a cleanout at the bottom of the wall, just right of the creosote? If there is cool basement air getting in around that panel thing, that will also help condense creosote, and reduce the draft. Was your boiler forced draft by chance?

 

[mmp]

How dirty did your boiler used to get? Did it use to make a lot of creosote within the unit itself? Require a lot of cleaning?

That chimney doesn't look all that high - I suspect you might not have enough draft (I think you also mentioned the fire is hard to start?). That together with how cold it is is likely condensing the creosote & also might be affecting the quality of the burn itself. You also mentioned the stove holding heat well overnight - that also might be a sign that it is not burning hard enough to burn off the nasties within. i.e., might be choked down. And if the boiler used to get dirty, it might have been condensing a lot of the nasties before they got to the chimney.

Was the creosote there before the makeup air pipe thing was installed? It might be cooling things even more and causing more condensation.

I'm also not familiar with either that boiler or that stove so not 100% in what I'm saying.

EDIT: I'm also curious what it looks like inside the bottom of the chimney. I think I see a cleanout at the bottom of the wall, just right of the creosote? If there is cool basement air getting in around that panel thing, that will also help condense creosote, and reduce the draft. Was your boiler forced draft by chance?

OK - Let's see if i can answer everything.
-The Clay liner is 8 x 8. The chimney has two liners, one for the fireplace & one for the wood stove.
-The clean out is about 2' below where the stovepipe goes into the chimney. The clean out has a door to seal it inside, and outside the door to the plate covering the clean out is stuffed with insulation. (The creosote seems to be leaking under the door, under the insulation and running down the wall.
- There are no open block cores inside the clean out.
- The chimney total height is 18' outside the house, the wood stove is in the basement, so the chimney for the wood stove is a little higher than 18'.
- Haven't tested the pipe temperature during the burn. We have now put the thermometer on the pipe and will check it next time..
- Our original Prairie Farm wood boiler (which was used day and night anytime it was under 40 deg., did not have a buildup of creosote. The flues (tubes through the water cabinet) were "punched" about every 2 weeks, along with the stove pipe, & the interior of the stove cleaned. What came off was very fine ash, no build up. Cleaning the whole chimney never resulted much more than a fine ash.
- there was no creosote before the makeup air was installed, but it was installed within 2 weeks of the stove going in, as it was hard to start.
- The clean out someone mentioned seeing at ground level to the right of the creosote is for the upstairs fireplace, which has it's own flue.

We cleaned the pipes & checked the chimney today. When we opened the clean out door, the only creosote showing was evidently where it flowed out on the floor of the clean out. There was only a few small "chimney shovels" of ash from the cleaning of the chimney, and an inspection of the chimney itself showed no buildup. It's a puzzle. Any ideas welcome. We have re-sealed the door which is about a foot into the wall behind the clean out door. Hopefully the new seal will help.