Clinging Creosote?

[1parkpointer]

I am finding a buildup of liquid creosote in the flue pipe of my wood furnace. It is coating every part including the Field R-C Damper, which I find difficulty in cleaning. I cannot seem to stop it from forming. Recently, I cleaned the flue pipe of the menacing stuff after a hot burn to bake it. The wood from the supplier was sold as seasoned and I have had it stacked for two months prior to burning. I found a load of year old seasoned wood, but the cost was close to bio-logs and I could only afford 1.5 cord.
My wood furnace heats the house really good, firebox temps running around 450 to 575 degrees Fahrenheit, and inside flue temps when I'm able to measure at around 390-degrees, and outside flue temps at around 195 to 250 degrees; temps measured with laser gauge.
Any ideas out there as how to adjust the furnace for a hotter burn or less creosote would be helpful?

 

[mike1234]

I cleaned the chimney on my super jack, which is only 2 months old. I also found a lot of creosote, way too much for burning it for a month. Since I have found this forum, I have found I was doing a lot wrong, too much wood too soon, not getting it hot enough, adding wood all the time. I think that I caused my problems, along with the fact that the furnace seems to pull every ounce of heat out of the smoke, so it can be too cool, and cause creosote.
What I am going to try, based oh what I have read here:
1. Get the furnace to at least 500 every time I add wood, before I shut down the damper.
2. Add smaller amounts until it's really cold outside.
3. Clean the chimney every month until I figure out a way to do it every other month.
4. Watch for more ideas from you all in this forum.

There are a couple of us super jack owners on here, we should make sure we exchange notes.

 

[1parkpointer]

I've noticed that when the burn cycle is nearing its end, and the furnace begins to cool off, and the creosote has a time to form. While I'm away at work, no one is home, and the fire does die back before I'm able to stoke it back up. I have also noticed creosote when the temps rise above 30-degrees and there isn't a big demand for heat, and the damper gets coated with a liquid form. I've taken apart the flue to clean as best as possible, but the creosote coats everything, and is nearly impossible to remove effectively.
I talked with the folks at Yukon-Eagle the other day trying to find some sort of way to stop the creosote buildup, and where to set the dampers in an attempt to ease the creosote buildup, but until the temps lower into the low twenties and below, creosote will be forming. They say a hot fire twice a day, once in the morning and again when I get it restarted in the early evening are best to put a stop to the buildup.
I can say one positive note however, beyond the creosote issue; that being the fantastic amount of heat that the furnace is capable of making. I wish I had gotten this years ago. At least I have one now! I'm with you on staying in touch! I was hoping that I'd be able to read about other Jack & Super Jack owners out there. Seems like everyone with a particular stove or furnace has certain issues that are common to the unit.

 

[pybyr]

I know nothing about your units- but as general suggestions, hard learned, from a number of years of previously running a wood/hot air furnace---

when in doubt, feed the intake more air, and do all that you can go give the draft less restriction.

only once you start having good results without creosote do you dare start throttling back either intake air or flue draft

then take it little by little, on either air or draft, and recognizing that both will vary with weather patterns, and carefully watching the results

I learned each of those things by trial and error a long time ago, and once I did, and learned to err on the side of a clean, safe burn rather than trying to throttle things down for some theoretical increased capture of heat, I've had good results, with only dusty carbon and ash in the flue, and a reasonable amount of heat (as much as one can ask from a relatively low tech solid fuel appliance)

hope that helps

 

[mike1234]

I too am very happy with the heat. I know I have been burning incorrectly, so I am glad it is so easy to clean my stovepipe monthly. I also think that I need 2 new thermometers to help me figure out what is going on, a probe for the stovepipe, and a lazer to see my actual temps.
My biggest gripe is burn time, and the suggestion to add more air, and less damper would make that worse, I think. Or maybe you could clarify that some for me.
Question, how do I know I have a secondary burn going? And if I have one, doesn't that burn the creosote in the top of the stove and by the damper? And if I shut the damper, does it put that secondary burn out?
Thanks,
Mike

 

[pybyr]

I too am very happy with the heat. I know I have been burning incorrectly, so I am glad it is so easy to clean my stovepipe monthly. I also think that I need 2 new thermometers to help me figure out what is going on, a probe for the stovepipe, and a lazer to see my actual temps.
My biggest gripe is burn time, and the suggestion to add more air, and less damper would make that worse, I think. Or maybe you could clarify that some for me.
Question, how do I know I have a secondary burn going? And if I have one, doesn't that burn the creosote in the top of the stove and by the damper? And if I shut the damper, does it put that secondary burn out?
Thanks,
Mike

again, I know nothing about your particular unit, so can't advise you on how to run it in particular.

I just know from my own experience with a Sam Daniel wood/ air furnaces (a design from the era of the locomotive, and built like one- splendid for what it is, and my friend who bought it will probably get many more years out of it) that after trying to do long fires and ending up with crud, I concluded it was better to err on the side of a clean burn, and "dial things in" towards a "slow/ long burn" only after I had achieved, and could maintain, a clean burn. Smoldery burns creating creosote aren't efficient anyway.

The best way I found to get longer burns while keeping it clean was to to get the largest pieces that I could find and handle (and fit in the furnace) of the densest hardwoods possible (well seasoned) and fill the firebox relatively full with those- after I'd started a good big bed of coals with smaller wood.

 

[1parkpointer]

This is my very first experience with a wood furnace, having used a wood stove on and off for nearly 25 years. Everything is different. My Larger Eagle wood stove was designed to burn wet/green wood, with seasoned wood used just to get the fire going. Once an initial fire was burning, the wet/green splits were introduced, eventually giving way to full round logs up to 12" x 32" in size. The Eagle produced an amazing 175,000 Btu of heat, and creosote was basically non-existent with main firebox temps at 700 to 750-degrees, the secondary in the 450 to 650 range and flue temps hovering around 325-degrees. Problem was that the heat was by convection only. We used fans to distribute the warm air as best as possible, but we always had cold rooms. With the wood stove sold, my only back up is the oil furnace, and I'd rather use wood instead of oil, for a much warmer home for much less money.

I get wood every year and rarely use it all, so I've got some 2 to 5-year old cords to go through before the last load of mixed seasoned & green dropped off this past August will be used.

Creosote problems are new to me and the new wood furnace drafts are completely different. The draft adjustment in the door is a small wheel covering two 1-inch holes, the combustion blower opening is around 2" across covered with a hinged door, plus there is a damper controlled secondary heat exchanger, and the Field R-C damper in the flue controlled with a weighted damper door. I'd like to get adjustments of drafts figured out so I can put a damper on the creosote issues.

 

[mike1234]

I am going to call Yukon tomorrow and ask them about covering the barometric damper. Not sure of the reason for it, and maybe it is dispensable. Given the amount of creosote I had been building up, (much of it my fault for the way I was burning) not allowing air into the chimney makes sense to me.

I also have a draft problem, which I thought was the reason for the barometric damper, so if I cover it maybe it will effect that for the positive also.

 

[1parkpointer]

mike1234,
Further up, you asked about closing a damper for a secondary burn inside the furnace. At the web site below, at the bottom of the page, the figure shows secondary air and how it effects the burn. I don't think that there is actually two burn cycles happening inside the unit. Rather extra air flow around the fire making a hotter fire and/or better burn cycle. The top damper on the SJ controls heat in the exchanger built above the cylindrical chamber and firebox. If you want more heat, push the rod inward, less heat pull it out. Yukon says the feature is helpful when loading fuel into the firebox, where you would pull the the rod out to open the back of the path to allow the smoke directly out of the unit rather than having it circulate through the exchanger.
http://www.yukon-eagle.com/FURNACES/SUPERJACK/VIEWDIMENSIONALINFO/tabid/168/Default.aspx
Hope this helps.

 

[1parkpointer]

P.S.
After your call to Yukon, please keep the thread informed, I'd like to know about covering up the baro damper to rid the creosote problem; Thanks!

 

[pybyr]

I am going to call Yukon tomorrow and ask them about covering the barometric damper. Not sure of the reason for it, and maybe it is dispensable. Given the amount of creosote I had been building up, (much of it my fault for the way I was burning) not allowing air into the chimney makes sense to me.

I also have a draft problem, which I thought was the reason for the barometric damper, so if I cover it maybe it will effect that for the positive also.

use hearth's advanced search to search "barometric" here in the boiler room.

also, go look at Field Controls' web site and some of its FAQs

A barometric damper has a legitimate purpose, at least when properly adjusted with a well engineered appliance, good fuel, and a decent chimney.

hate to sound short, but I am thoroughly tired of trying to articulate the same points over and over in response to rumor and speculation and trial and error about this point

if, after doing your own homework, you decide that barometric dampers are awful or some kind of conspiracy, either in general, or on a wood appliance in particular, please don't debate me over it-- just make your choice and enjoy.

PS, I wondered and worried about these factors, too, and Hansson, from Scandanavia (where they are way ahead of us in using wood efficiently) , who comes 'round here from time to time, has said repeatedly that barometric dampers are the norm on wood units over there.

 

[pybyr]

an anecdotal suggestion, as I continue to rip out my old wood-hot-air system and plan and install my new more efficient wood gasifier system

it seems to me, that the closer you can locate the barometric damper to the vertical chimney, the better, especially if there's any horizontal length or elbows between the wood appliance and the vertical chimey

reason being, that the barometric damper will indeed introduce cooler air into the combustion fumes-- not that that's a hideous thing if it is all set up and running right, but you might as well do it only as close as possible to the location where the fumes are ready to go "up and out" - in case you are "near" condensation point of anything, anywhere in the system

and, in any event, if your combustion fumes are so close to liquid creosote that the barometric damper makes a difference one way or another, then you need to look for bigger problems than the barometric damper.

 

[mike1234]

pybyr,
Thank you for your input, and I certainly would not argue with it, I have a total of 2 months of experience heating my house with wood. When someone makes a suggestion, I jump on it, looking to do this right.

As far as the barometric damper, you are right, lots of opinions. Mine is directly above the T that comes out of the stove, so it could not be closer to the stove.

Since I cleaned out the stove pipe yesterday, I have worked hard to maintain hot fires, and it seems to be working - much less smoke, great heat. Still that damper is a little confusing to me, maybe because there is lots of advice around about it (keep it closed, keep the heat in, leave it open, need more flame and heat in stove pipe, open at beginning, closed later, open burn more wood, closed burn less wood, .... ). For now what I think I've learned, open it until the fire is hot (I'm using a magnetic thermometer) 400 at least, I got it to 600 this morning. Then, shut down the damper most of the way, maybe leave 1/4 to 1/8th. If it gets really cold out, then leave it more open. Does that sound about right to you? Air supply is governed by the electronics in the stove.

In the link you sent, if you look at the bottom left you will see the words "Secondary combustion air chamber feature." I was assuming that meant that there was a secondary gas burning thing going on. But assumptions are dangerous things. I'll ask Yukon about it tomorrow on the phone.

I have to say, the biggest joy I get out of the whole heating with wood thing so far, 73 in the house most of the time (too hot for me, but wife, daughter and mom-in-law like that heat) and not one drop of complaining about, can we turn the heat up?

Again, thank you for your input, I need all the help I can get.
Mike

 

[pybyr]

pybyr,
Thank you for your input, and I certainly would not argue with it, I have a total of 2 months of experience heating my house with wood. When someone makes a suggestion, I jump on it, looking to do this right.

As far as the barometric damper, you are right, lots of opinions. Mine is directly above the T that comes out of the stove, so it could not be closer to the stove.

Since I cleaned out the stove pipe yesterday, I have worked hard to maintain hot fires, and it seems to be working - much less smoke, great heat. Still that damper is a little confusing to me, maybe because there is lots of advice around about it (keep it closed, keep the heat in, leave it open, need more flame and heat in stove pipe, open at beginning, closed later, open burn more wood, closed burn less wood, .... ). For now what I think I've learned, open it until the fire is hot (I'm using a magnetic thermometer) 400 at least, I got it to 600 this morning. Then, shut down the damper most of the way, maybe leave 1/4 to 1/8th. If it gets really cold out, then leave it more open. Does that sound about right to you? Air supply is governed by the electronics in the stove.

In the link you sent, if you look at the bottom left you will see the words "Secondary combustion air chamber feature." I was assuming that meant that there was a secondary gas burning thing going on. But assumptions are dangerous things. I'll ask Yukon about it tomorrow on the phone.

I have to say, the biggest joy I get out of the whole heating with wood thing so far, 73 in the house most of the time (too hot for me, but wife, daughter and mom-in-law like that heat) and not one drop of complaining about, can we turn the heat up?

Again, thank you for your input, I need all the help I can get.
Mike

be well, and apologies that I snapped at you guys.

We really need to find a way to help people set up barometric dampers correctly without a multi-hundred dollar gauge, which is the norm for the pros to do it right (and too many "pros" don't seem to do it with the gauge).

eyes and guesses and seat of the pants don't do it- I learned that from trying. how do I know that a lot of pros don't do it right, well, I watched a few....

get the appropriate "overfire" or stack draft from your manufacturer and post it here; I will then try to check with some benevolent mad scientists who I an acquainted with to see how we can develop a DIY-er's manometer that can read on the appropriate scale of 1/100s of an inch of water column of draft. this will be good for all around these parts. I will most likely not be able to do it right away, as I, myself, am up to my armpits in alligators

 

[1parkpointer]

pybyr,
I originally had the weight on the damper door hung on the horizontal adjustment side. When I asked about the creosote problem in another forum, it was suggested that since I had a sloped flue that I should hang the weight from the vertical side. I did that, and it didn't change anything.
I went to Field Controls FAQs as suggested and learned something. Apparently sloped flues are considered horizontal and not vertical as I was told before, and I need to re-hang the weight back to the right side slot for my sloped (horizontal setting) flue.
Thanks for the suggestion, as I too, am new to the wood furnace concept.

 

[pybyr]

pybyr,
I originally had the weight on the damper door hung on the horizontal adjustment side. When I asked about the creosote problem in another forum, it was suggested that since I had a sloped flue that I should hang the weight from the vertical side. I did that, and it didn't change anything.
I went to Field Controls FAQs as suggested and learned something. Apparently sloped flues are considered horizontal and not vertical as I was told before, and I need to re-hang the weight back to the right side slot for my sloped (horizontal setting) flue.
Thanks for the suggestion, as I too, am new to the wood furnace concept.

repeated disclosure- I am not a pro- just an enthusiast--

that said, get a bubble level

then-

make sure the face of the barometric damper is vertical

make sure the pivot point is horizontal

then set the B.D's draft to the proper fraction of an inch of water column of draft for your furnace. the measurements/calibrations on the barometric damper are better than nothing, but not by much.... some form of draft gauge or manometer is really needed

be well, good luck.

 

[Gator eye]

things I ve learned about my Yukon Jack wood furnace after 1 1/2 years of buning wood with it.

It loves to make cresote even with well season wood. The best reason I ve been able to come up with is the draft inducer fan. It make a nice hot fire followed by long periods of choking the fire for air, then repeat this cycle all over again. This is a perfect way to make a hard glazed cresote that just will not brush out of the chimney.

This is what I ve been doing and greatly reduced my cresote levels in my chimney. I ve went from cleaning my pipe and chimney once every two weeks to once a month, and might be able to go more now that the weather is turning colder.

First, I ve unplugged the draft inducer fan and use the manual draft on the door and the plate on the fan to control the draft. Instead of running a fire in hot and cold cycles I use the manual draft to have a constant steady hot fire. I load the stove and open the ash door for 5 minutes or so and get a good hot fire and then shut the door down and adjust manual draft.

I can get a overnight burn out of it fairly easy this way and doesn't make near as much cresote...

Only down side.........with a constant hot fire means the blower fan runs more which make the house almost to warm.........I sleep with my windows open most nights.

 

[mike1234]

Thanks for your input, it really helps. A couple of questions about how you are running your stove:
After getting that good hot fire going, do you shut the damper to closed, 1/4, 1/2, ?
Also the manual draft control on the door, one turn open, 1/2, ?
And the opening on the draft fan, how much do you leave that open?
How much wood, all the way full?

I know all of these would change depending on the weather, but let's say a 30 degree night, and you are not wanting to get up at 3 to feed the fire.

Thanks for your help.
Mike

 

[Gator eye]

Thanks for your input, it really helps. A couple of questions about how you are running your stove:
After getting that good hot fire going, do you shut the damper to closed, 1/4, 1/2, ?
Also the manual draft control on the door, one turn open, 1/2, ?
And the opening on the draft fan, how much do you leave that open?
How much wood, all the way full?

I know all of these would change depending on the weather, but let's say a 30 degree night, and you are not wanting to get up at 3 to feed the fire.

Thanks for your help.
Mike

I don't pack the fire box tight full, but I do fill it up with in reason at night. After I get it burning I set the door draft one and a half turns open and I leave the flap on the inducer fan around half open. I seem to get a real good burn that way. I fill around 9:30 or so and most time if I am using decent wood I have a good bed of coals at 5 am when I get up. I ve even pushed it intil 6 or 7 in the morning on the weekends and still had coal to restart the fire with out using kindlin or anything.

After cleaning the chimney this weekend I might even try only giving the door draft one full turn and see how that does.

One thing to keep in mind, when you open the ash door to get a good hot fire, shut the draft control on the door or smoke will come out if it. And of course don't walk away and forget the ash door is open..........what can I say,I get side tracted easily.

 

[mike1234]

This is the summary of my discussion with Yukon today.
1. You need to barometric damper (this is not the correct term, but I am not sure what the correct term is), because it is what allows the wood to smolder in the firebox and not need to let much smoke up the chimney to create creosote. What is suppose to happen, fire is smoldering, a little air from the air intake on the door slides in (see #2), allows the gases to burn in that secondary burn, very little smoke is left to go up chimney. Chimney is not pulling air in, because the barometric damper is supplying that air, so any creosote you create you create in the burn chamber, where it will burn off with the next hot fire.
1A. However, unless the barometric damper it is set up correctly, it is not doing you any good. This may be problem #1 with creosote. 1B. As far as setting it up correctly, well either a HVAC person or maybe someone on here can help with this, we have had some offers...
2. The air intake on the door should always be open a little, that allows some air into the firebox to allow the secondary burn to take place, even during smoldering times.
3. Close the damper at the top of the stove all the way once the fire is hot. This also is to get the secondary burn going as effectively as possible.
4. Fresh air. Fresh air. Fresh air. There needs to be a good air supply to the stove, inside air is not ok.

That is from my 1/2 hour conversation today with Yukon. Gives me some new ideas, and creates one big problem, how to set the barometric damper.

Mike

 

[mike1234]

After 2 days of running the stove as advised above by Yukon, things look better. I think the creosote build up is much less (next months cleaning will be the real test) and I have the stove the hottest for the longest periods of time - about 500 measured just above the door with 2 magnetic thermometers.

I have one complaint - I get 4 hour burn times. Admittedly I am burning crap wood, I have lots of great dry hedge and oak, but I want to get rid of the 2 cords of crap that was just standing there dead, or I cut in the last couple of years. I still think I should be able to get at least 1 more hour out of it before reloading, and I am looking for 2 more hours out of it when I start to add the good stuff.

I also am having my HJVAC man come to adjust the barometric damper, hopefully this week.

Anybody else having burn time issues, and any other input on how things are working.

 

[mike1234]

More new info from Yukon. My 2 biggest mistakes, not enough fresh air, and barometric damper set incorrectly.
Even though I have my superjack set up in a drafty garage, it still may not be getting enough fresh air, I will set up a fresh air supply for it tomorrow.
I am burning too much wood because the air for the chimney is having to travel trough the stove, instead of being able to idle and have the barometric damper set up to supply that air. I am learning that this is not a wood stove, so I should not treat it like my wood stoves, it is a furnace and is run differently.
The 500 I was temping at is probably too hot and burns too much fuel caused by the barometric damper being set incorrectly.
That's what I am learning, hope it helps you and you correct me when I am way off base.
Mike

 

[laynes69]

I run a baro on my woodfurnace only because I have overdraft. It does make a difference. The firebox has lazy flames, which in return higher temps, more complete combustion. Sounds like yours isn't opening up enough. I have my baro almost to the chimney that way the flue stays hot and clean. As far as buildup on the baro, no matter what it will happen. You have startup and the end of the burning cycles that will produce some smoke. I clean mine once a month. I just remove mine and light it, then brush it off and reinstall.

 

[Gator eye]

Keep us updated Mike.

I'm real interested on the amount of cresote your going to produce burning this way.

What is your blower fan set at? And what temp do you have your draft inducer fan set at?

 

[mike1234]

I will keep you updated. I still don't have my baro set right, waiting for my HVAC man, time to start to bug him to get over here.
Today I installed a 2" PVC air intake that runs just to the right side of the blower fan, so I solved any issue with air supply.
The draft inducer fan is set according to the weather, right now (39 outside), at just under 1/2, all the way open when it is cold outside.
The limiter for the blower is set 100 / 180 / 230, (blower stays on until heat in stove plenum falls under 100, blower goes on when the heat hits 180, kicks the draft inducer fan off at 230.
I have the door draft open right at 2 turns.
I have a small fire going, put in 4 or 5 very small rounds (well maybe big sticks) an hour ago, stove is at 320, almost no smoke.
I'll just have to wait and see on creosote until I clean the stove pipe in January.
Mike