creosote.... at witts end!!!

[chrisman34]

I can't figure out why i keep getting creosote build up. My wood is (I assume) red oak, maple, and ironwood. I assume this based on previous owners statements that he cut dead wood on the ground and that is primarily what I have in my woods. The ends are cracked, cheapo meter is showing less than 20% moisture...... I run my stack to about 350, hold for an hour or so and then shut primary down to 1/4 open.....still get secondary burn and some primary flame... I am very paranoid about chimney fire as I am a firefighter, and an insurance agent, but I am cleaning this thing about once a week, getting a cup to a cup and a half of shiny crap...as well a coating that wont come out. Although very paranoid, I wait until I can hear stuff falling down the chimney and that's when I sweep it. At first I wasn't running the temp up enough...so I thought.... But this last week I believe I did things right, and I am hearing crap fall down the chimney. I am letting it go out tonight to sweep in morning but this is getting really old. Any idea what could be wrong? Is 350 on the stack still not enough? Could it still be the wood even though there is no sizzling and nothing coming out the ends? I can't keep sweeping this thing every week!

As the signature states I have a lopi endeavor...and there is very seldom any smoke.

THANKS FOR HE HELP

 

[gpcollen1]

I do not care how bad the wood is, once per week is paranoid. I do not monitor stack temp, but that sounds low regardless. Did you search your stove model and stack temp to see if there is any info out there.

 

[billb3]

concrete block chimney running up an outside wall ?

 

[ansehnlich1]

Hey I ain't trackin' my stove gas temps either, but I figure if my stove top is at 700 degrees, likely the flue gas is at least that, or more.

I'll get me a stack thermometer sometime soon.

I'm sayin 350 is to cool.

 

[chrisman34]

The dealer said over 250 is ok, the only info I can find stove specific is 800 above the door(on the stove) is over temp... My stove top runs around 500 to 550 most of the time until it burns down to coals ten slowly goes back to 200 or so by morning..and return from work.

 

[chrisman34]

concrete block chimney running up an outside wall ?

Sorry knew i was forgetting something... single wall straight up inside about 8 feet then into double wall threw cieling roof etc. and i would say that is about 8 feet total?
And stack temp is taken on the outside of single wall pipe about a foot above the stove.

 

[BrotherBart]

You have a nasty draft leak somewhere in the pipe. It is pulling in cold air and condensing the stuff in your chimney.

Edit. Take the pipe apart and you will see where the creosote starts. That will be where the leak is.

 

[chrisman34]

You have a nasty draft leak somewhere in the pipe. It is pulling in cold air and condensing the stuff in your chimney.

I did, but have sealed those up...I think.... There was a bad leak at the stove collar and where 2 lengths couple. sealed those up and it made a big difference in how the stove ran. before that i would get stove top to 550 and stack would be 250 So I have atleast helped that as the stack heats up quicker and stays hotter now.
edit I will look again tomarrow when I take it down... in the past it has been in the lower sections.

 

[KeithO]

My Stove (Morso 7100) will have a stack temp of >450 when putting out meaningful heat. Right now with temperatures just above / below freezing at least 500F. If your producing too much creosote it will show in other ways like dirty glass and soot covered refractory brick. On the other hand, if you have an outside (cold) chimney, you will certainly get more creosote under identical conditions since the colder flue will always encourage more condensation.

So, with 2 possible options (burning too cool and a cold outside chimney) the solution to either, or both is to burn shorter and hotter and then allow the stove to coast through the coal phase. I am sure to raise my flue temp to about 1000F daily for at least 5 minutes to help dry out any creosote deposits that may have formed in the flue overnight. I know I have burnt some "suspect" wood but so far I have no problems.

 

[chrisman34]

My Stove (Morso 7100) will have a stack temp of >450 when putting out meaningful heat. Right now with temperatures just above / below freezing at least 500F. If your producing too much creosote it will show in other ways like dirty glass and soot covered refractory brick. On the other hand, if you have an outside (cold) chimney, you will certainly get more creosote under identical conditions since the colder flue will always encourage more condensation.

So, with 2 possible options (burning too cool and a cold outside chimney) the solution to either, or both is to burn shorter and hotter and then allow the stove to coast through the coal phase. I am sure to raise my flue temp to about 1000F daily for at least 5 minutes to help dry out any creosote deposits that may have formed in the flue overnight. I know I have burnt some "suspect" wood but so far I have no problems.

I dont think i can get my stack that high without overfireing! I know i can get hotter, hottest i have attained is 450, (not comfortable there, becouse of my fears that i am working on, I am getting better honest).....but at 450 on the stove pipe 1 foot above collar, stovetop was 700.... and I am supposedly not supposed to go over 800 stovetop.

 

[BrotherBart]

You have a nasty draft leak somewhere in the pipe. It is pulling in cold air and condensing the stuff in your chimney.

I did, but have sealed those up...I think.... There was a bad leak at the stove collar and where 2 lengths couple. sealed those up and it made a big difference in how the stove ran. before that i would get stove top to 550 and stack would be 250 So I have atleast helped that as the stack heats up quicker and stays hotter now.
edit I will look again tomarrow when I take it down... in the past it has been in the lower sections.

Just as an example, I run two stoves. One in the basement on a 33 foot pipe/liner set up with two 90* turns and one on the first floor with a 21 foot liner straight up. Both into exterior flex lined masonry chimneys. I run the one in the basement between 400 and 550, usually 500, and the one upstairs at 500 - 550. No thermo on the pipe upstairs but the one downstairs max's at around 350 to 400 surface temp on a startup of fresh wood on hot coals. And with our goofy winters they get started up and burned down over and over and over.

And the only thing other than powdered soot I have seen in two years in either pipe is some flakes on the caps.

That sumbitch is leaking somewhere bro.

 

[chrisman34]

That sumbitch is leaking somewhere bro.

I will look tomarrow, and seal the crap outta the joints. I have run a lighter around the connections and the flame is not being drown in anyplace. I will check it, in the past it definately needed it, I am hopeing I am just paranoid now... If it needs it and i cant find a leak I will try to burn hotter.

Thanks for all who posted, I will reply with what i find after I sweep!

 

[billb3]

I've never seen creosote build up in pipe, just outside chimneys.
Cold leaking outside block chimneys.
Cold leaking block chimneys with oversized stoves throttled back way too far burning not so dry wood.

 

[chrisman34]

people think it's my wood that's why I got the meeter, Its been under a deck for a minimum of 2 years. Some of it is wet on the outside but i put it near the stove a few days and wont burn it until it is below 20%.... My only answer at this point is I am still not burning hot enough or maybe a leak in the pipes like what was suggested previously. The only other thing I can think of is indoor humidity..running about 45%.....I will get icicles on zero degree days, and I am sure the moisture isn't coming from the wood! But where else is it getting picked up! I wouldn't think the humidity inside would do it... but who knows. I am trying real hard to like this thing but am having a hard time.....

Just a though here could it be secondary air coming in too much, cooling things down? 90% of the time i have secondary burn until it goes to coal, then there still seems to be secondaries, just not up by the tubes. I just don't think there is a leak in the pipes and I am also quite certain the wood is ok...hence my frustration.

 

[billb3]

It sure sounds like you got your stove burning close to right, but something sure doesn't sound right with your chimney.
Icicles where ?

For the life of me I can't picture icicles ona chimney.

I can't even imagine a tiny bit of condensation frost way up near the top lasting more than a few minutes in the morning when starting the stove back up.

 

[chrisman34]

hanging off the cap. had huge ones in the morning when i got up, an hour and a half later burning around 300 pipe 500 stovetop and there were just some small ones. Came home, about 9 hours later, wife came home 1.5 hours before me and ran about the same temps, and still small icecicles....went to bed and they were there but real small. They only for when temps get below 10 degrees. (only twice this year or a couple days each) I have pics will try to send tomarrow.

 

[RonB]

Occasionally, I get small icicles on my masonry chimney. Since they have formed outside of the flue, on other masonry surfaces, they don't bother me. It shows the the moisture that remained in the wood made it all the way up the flue without condensing on the flue surface. Once it hits my metal cap it sheds off the underside to the cap edge and drips onto the masonry surface below (which is outside of the flue). I can also estimate how clean a burn I am getting by the color of the icicle. I am burning correctly this year with a newly poured cast-in-place flue and new stove. All this to say; the icicle issue may not be related to chrisman34's creosote problem.

 

[crazy_dan]

I'm not sure about temp but the outside of my stove pipe is too hot hot to keep your hand on and it is double wall inside then in to class A. If you have a strait run up you might want to look at an adjustable piece of double wall for inside as it will keep your flue temps higher, and a single piece of adjustable pipe will decrease the amount of joints.

 

[chrisman34]

well here's the update, roughly 3 cups of creosote in a week :gulp: Started right out of the colar that I know was sealed well. Pipe restricted by creasote by about a 1/4. I got about 2 cups out of the lower single wall, flaky, shiny, bubly stuff... Upper was more powder than flakes, and got about a cup. My card reader is at work so I will send pics of cicles and the inside of pipes from this morning when i get there. I guess I will try burning hotter longer and see if this helps. Am I better to burn open with fewer secondaries or closed some and lots of secondaries? :question:

 

[argus66]

im no expert but mayby try burning bio bricks or some kind of compressed log till u can fix it. no creosote from them. and u can have fires with no worries.

 

[chrisman34]

as promised, heres a link to the photo's http://www.flickr.com/photos/8235414@N04/sets/72157603865036300/

 

[Wolves-Lower]

That is interesting.
I have seen icicles below my cap as well. Not big ones and only when it is deadly cold out.
I will be following this thread.

 

[Jags]

Whoa dude, that is in a week??? You got cold air pumping to that pipe somehow. I personally use a probe therm. so I am not well versed with surface temps, but I would assume that at the 325 deg surface temps you mentioned earlier, that you would have an internal temp much higher (say above 500). That should ward of a case of the creasotes much better than your pictures show.

Suggestion: Bring your stove up to temp, use an incense stick (light up of course) and VERY methodically test all your joints on your pipe. Any leak should suck up that wisp of smoke in short order. Also do this anywhere on your stove that COULD be a place for air leaking in.

Note: If your pictures of the smoke rolling from your stack are at "operational" temps, you got problems. Either your burning horse sh!t, your wood ain't seasoned, or you are not burning hot enough. I say this because even if you have stack air leaks, what leaves your stove should NOT have that much smoke in it. And air leaks don't "make" smoke.

 

[moondoggy]

"Either your burning horse sh!t, your wood ain’t seasoned"
lol that is the comment of the week.

 

[BrotherBart]

Do you have the optional blower on that stove and if so how long do you wait after start-up to turn it on? The reason I ask is that is burned glaze creosote. Somewhere along the line it is glazing and then burning later.