Had Chimney Fire.............now what?

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
Status
Not open for further replies.

longboarder2

Member
Feb 14, 2012
87
southern NJ
hello, new to this site----thanks to jeff from maine wood furnaces for telling me about it---he has been a fantastic resource for me even though shipping costs prevented me from buying my appliance from him.

my equipment: harman sf160 add-on wood/coal boiler, 6" hart & cooley all fuel (30' from wall thimble to roof cap) 90 out of unit--4' smoke pipe--90---4' through thimble into "t" and up the 30' to cap.

heating 3000 sq. ft. with baseboard and radiant heat in (4) tile floors, domestic hot water (super store indirect), using 1100 sq. ft. finished bsmnt as a dump zone (30' of slant fin fed by about 80' of copper)


we've had an unseasonably warm winter here in southern nj and i have been burning wood since nov. during the warmer days early on i was keeping the unit smoldering thru the day and letting it roll hot at night when the temps went down. after three weeks, i took apart the smoke pipe and removed the chimeny cap to see how things were going-----about 1/4" of "fuzz" had formed in the smoke pipe and i observed the same in the last segment of all fuel at the chimney cap---no hard scale, just a dry black sooty buildup. i cleaned the smoke pipe and fittings, chimney cap, and firebox and went back at it.

after seeing the buildup that occurred in just 3 weeks of burning, i decided i needed a new strategy. i upped the demand on all my thermostats to 69 or 70 degrees for most of the day, with the last zone clicking down at 2am. every time i went into the garage and saw the air door closed, i would up a zone to make it burn instead of idiling. on 35 plus degree days, i would saturate all the regular zones with heat and at about 11am prop open the thermostatic air door let the fire burn out instead of smolder and just run the dump zone constantly to get rid of the heat, turning the circulators off once the water temp dropped below 140---this seemed to make it easier to light in the evening when the temps went nack down into the 30's or 20's.

my oil and wood all-fuel stacks run up through the center of my house in a framed chase. last thurs. i heard a crackling sound in the wall upstairs that souned like popcorn popping or pine burning on a campfire. i went outside to see my framed chimney tower on fire---burnt into the attic and upstairs bedroom via the framed chase and falling embers.

the wood i have been burning i mostly oak and was split in august of last summer, but was sitting in rounds for two years prior. after reading some similar topics, i'm certain wet wood was part of my problem---some of it was pretty rotted maple that had been cut/split for a long time, but seemed to wick moisture out of the air. possibly too small of a flu pipe @ 6", and not the best open style flue cap. additionally, the flue cap was only about 6" above the tower cap. the tower was vynil sided.

now that the ins. company is involved and we are replacing everything (my h&c all-fuel TDC model was discontinued shortly after we installed it), we are making the following improvements: 7" all fuel from the unit to the roof, with fireproof insulation for the 30' contained in the chase. stone veneer on the chimney tower with a stainless cap. taller, more open mesh caps on the flue pipes, some additional clearance between the flue and the wood framing. flue cap sitting 18" above chimney tower with rain collar added.

what else can help me not have the creosote/soot buildup while still beating the oil company?

with normal winter temps, i was thinking of running my house at about 74 degrees all day to increase the demand on the unit and prevent idiling. additionally, i was thinking about leaving the thermostatic air inlet open starting around 11pm, running the basement dump zone and letting the fire burn down through the night instead of smoldering until demand increases at 6am.

know this--- i have very liberal supply of wood and a 12x22 carport to store it under, it never stays too cold for very long here in nj, i don't work much in the winter so i am available to babysit the unit.

can anyone provide some advice to pevent this from happening again? there were alot of "ifs" that could have resulted in much more damage--so i don't want them to come true.

any help would be appreciated. thanks.

regards, mike
 
idleing is bad. Burn small hot fires. That means you have to load more ofter depending on the weather. Try and time the fires so you burn the wood down to charcoal each time. When you have charcoal it does't produce as much creasote. You will also use less wood.
leaddog
 
It takes 2 years for oak to dry after it is split.

1 burn dry wood

2 no ideling (small hot fires)

3 Add storage to reduce ideling if you don't want to do small hot fires a few times a day.
 
longboarder2 said:
..... the wood i have been burning i mostly oak and was split in august of last summer, but was sitting in rounds for two years prior. after reading some similar topics, i'm certain wet wood was part of my problem---some of it was pretty rotted maple that had been cut/split for a long time, but seemed to wick moisture out of the air. .......
Unfortunate, but considering the alternatives, you came out of that ok :roll:
I'm assuming "cut and split inaugust of last summer" means 2011, which is not good. Unless split really small, your oak is probably around 35% - basically 1 or 2 steps above green. And yes, the rotted wood probably is wet inside as well. Have you checked the MC with a meter? If not you should do that, so you know exactly what you're dealing with. Your best long-term solution is to add storage, but that's not going to help you today. Without storage myself, I run the smallest possible fire, as previously mentioned. A very common fire for us during the day is just 3-5 smallish splits. Yes, this requires more frequent loading, but the boiler is in the basement, so no problem at all with that. We also let the fire go out whenever possible - sometimes for a number of consecutive hours (good solar gain). From what you wrote, it sounds like you could also use some of this strategy, but the wet wood works against that in a big way. Our well-seasoned wood allows a very fast restart. So, can you get hold of a bunch of dry kindling, assuming you don't have that already? Wood pallets or KD lumber (but not PT!) makes excellent fire starter if you don't have anything else. It could also be a huge plus to mix in pallets with your current firewood. Also you mentioned letting the boiler temp drop down, but that also works against a fast restart. When letting the fire go out, we always try time it so the boiler is empty of wood, but at the highest possible water temp. Then, even after a number of hours, the boiler temp is still within the range that allows fast and easy restart. If you able to "babysit" the boiler as you said, then reducing idling (at least during the waking hours) is something you can make good progress on.
 
so by small, hot fires, you mean adding a couple splits every hour or so as in the case with a conventional wood stove---no more filling the firebox to the top before bedtime?
 
You can find affordable moisture meters on Amazon, Northern Tool, etc. I would not recommend spending a lot of money on one. This tool is something a wood burner will probably only use for the first year or two. Once you get your wood piles organized and a process esatblished to always be 2 years ahead of your wood demand you will no longer need to measure moisture.

As already stated above you really can't expect any kind of oak to season quickly. Most folks say minimum two years AFTER splitting and stacking. Standing dead or cut into rounds on the ground can many times be just as green as a freshly cut tree.
 
longboarder2 said:
so by small, hot fires, you mean adding a couple splits every hour or so as in the case with a conventional wood stove---no more filling the firebox to the top before bedtime?

Another way to say this is "adjust the size of the fuel load based on (expected) outside temps" It sounds like the boiler is oversized, so a full firebox may only be appropriate on the very coldest days of the year.

Increasing the load as you have is a good short-term way to deal with this. You may want to consider setting your dump zone aquastat at 190 or 195 so that it comes on sooner and more often. A waste of heat/wood, but will keep the boiler out of idle more.

As all others have said, including yourself, dry wood is key. Mix pallets or biobricks in with your current wood and things should improve. Also, get next year's wood put up ASAP (split and stacked). Split it a little smaller than you think you should and give it plenty of time - oak takes an especially long time to dry.

Sounds like the new chimney system is a big improvement, I'm sure you'll be fine going forward.

Chris

PS: you mentioned something about a "liberal wood supply" - that may be the source of your problems. When all else fails, blame the Liberals! :)
 
  • Like
Reactions: Mainewood
PS: you mentioned something about a “liberal wood supply†- that may be the source of your problems. When all else fails, blame the Liberals!

Blaming the liberals obviously isn't going to help the guys heating problems. Blaming the liberals is already proven to be one of the biggest and most reliable sources of hot air in the nation.
 
longboarder2 said:
so by small, hot fires, you mean adding a couple splits every hour or so as in the case with a conventional wood stove---no more filling the firebox to the top before bedtime?
Yes, the comparison to a woodstove is accurate, but you will not have great success burning just a few splits if the wood is not dry (20% or less). All you will get is a smokey sizzle. BUT for most folks, small fires would normally only apply to the waking hours. It would be difficult to imagine anyone getting up during the night to feed the fire every hour or so :bug:. For me, as bedtime and the nighttime fire approaches, I will let the boiler temp and house temp drop down as low as possible, based on current Weather. Reheating gives the boiler something useful to do from the nighttime load. After the reheat, some idling is inevitable, except on the few design days that we get. On some shoulder season days, I do get up once in the middle of the night to shut everything down for the remainder of the night. Fortunately don't have any problem getting back to sleep after this quick trip downstairs :). One big mistake that I made during the first year was to continue to do house temp setback - a leftover habit from fossil days. Wood boilers sans storage are non-modulating, and want to produce lots of heat continuously. Setback was a complete mismatch with how the boiler operates. I would suggest that you experiment with different loading amounts, patterns, and timings (including shutting down for periods, whenever possible). You may find somthing works for you that's completely different than what I described above.
 
where can i pick up a tool to read the moisture content of the wood? what is the preferred range?

Although this may sound facetious, it is meant to be serious. The tool is a calendar along with cut, split and stacked fire wood with good air circulation and off the ground. The preferred range for me is two full summers of drying, regardless of the species of wood.
 
jebatty said:
where can i pick up a tool to read the moisture content of the wood? what is the preferred range?

Although this may sound facetious, it is meant to be serious. The tool is a calendar along with cut, split and stacked fire wood with good air circulation and off the ground. The preferred range for me is two full summers of drying, regardless of the species of wood.
And a time machine to put you into the future so the wood you have now is dry.
 
Burning dry wood....that means you should have the 2013-2014 season stacked outside and drying....then you will be assured you have dry wood. That's the primary key.

Sounds like you were really lucky!
 
what really suck is that when i first decided i wanted to install a wood boiler, three years ago, i split three cords of wood and had it sitting in my yard for two years---presumably ready to burn (once stacked). i havd the following years' wood sitting in rounds waiting to be split so i would be on schedule w/ my rotation. i blew off the project and sold the wood so it didn't sit here and rot. once i finally decided to put in the boiler this year, i felt under the gun--split the wood in the summer and figured i'd be fine.

down here in the mid-atlantic most people have a very different concept of "seasoned" wood than you guys who actually have cold winters do. i drove to minnesota to pick up a race car a few years ago----what we have is training for what you guys live through.

so, here i am with about 3 cords of round wood that will be split by monday and stacked under the carport----nowhere ready for next season.

totally educational
 
since my boiler is set up for coal, do you guys think it would be pennywise to burn coal (versus buying oil) next year while the wood is drying for the following season? anything i need to know about burning coal that is very different than wood?
 
also, was the "fuzy" buildup that i observed in my flue pipes in fact creosote? harman says that a creosote buildup of 1/4 to 1/2 inch inside the chamber is normal. what i observe in my chamber is a black tar-like coating that never gets more than 1/8 inch or so thick and burns off with a nice hot flame. i didn'thave anything like that in the flue pipes.
 
longboarder2 said:
since my boiler is set up for coal, do you guys think it would be pennywise to burn coal (versus buying oil) next year while the wood is drying for the following season? anything i need to know about burning coal that is very different than wood?

I think it would be pennywise to burn coal over oil next year but coal is a totally different ball game. Coal will eat away at your stainless chimney although if it is only for a season you might be ok. Check out this website to learn all about coal burning http://nepacrossroads.com/ . The guys on there are very knowledgeable and willing to help.
 
I've also from South Jersey (Cumberland County) and I've actually gone through what you're going through right now... I've got a New Yorker WC130, which I believe is a similar design to yours... the first few years I ran it on wood, I also had excessive idiling, and creosote problems (even with oak aged 3+ years) I was cleaning my chimney every month and still had a pretty nasty chimney fire at the end of last season... it just doesn't stay consistently cold enough around here, when it was 30 degrees plus, it was a creosote factory, and below 25 degrees, needs to be filled every 6 hours... I've been burning coal in mine ever since and I'm very happy with it, longer burns, no creosote, no splitting/stacking... I know coal isn't for everyone, but as I was buying my firewood anyway, it still makes financial sense... if you're considering burning coal, I second the recommendation for the nepa coal forum, tons of info over there....


longboarder2 said:
since my boiler is set up for coal, do you guys think it would be pennywise to burn coal (versus buying oil) next year while the wood is drying for the following season? anything i need to know about burning coal that is very different than wood?
 
shawn,

were you cleaning the chinmey every month or paying someone to do it? also did you switch to small, hot fires, rather than stuffing it with wood for say, "overnight" burns?

if i keep the air feeding the thing and don't allow it to idle and always burn it down to coals---basically treating itlike a wood stove will i still see the creosote issues?
 
i'm thinking i can pull that off by running my dump zone more often and for longer periods of time when the temps are 30 plus---mainly because my basement dump zone doesn't have a thermostat, it's striclty controlled by the wood boiler controls. it's a basement, so it's always cooler than the rest of the house and the heat is always going to rise.

whaddya think?
 
So have you considered installing storage? Storage in this sense is, say, 1000 gallons of water in a tank. When you burn, you burn hot and fast, and dump all of your heat into the 1000 gallon storage tank....and whatever the load might be at the time for the house/DHW. SO, in this case, the fire never idles, it is always straight out 100%, and you never overheat, becuase you are heating up this big tank. Then you can take the heat back out of the big tank to heat the house and DHW. When your tank gets cool, where cool depends on your type of heat, but can be down to say 120 or so if you are using radiant heat....then you have another fire. Most of us here with gasifying boilers have a setup like this. It means your boiler NEVER has to idle.

Now, dry wood is still very important....and if you stacked the stuff this past summer, especially oak, that's a huge part of the problem. With this mild weather, it's another....

Most species, if you had it split and stacked now, would likely be fine for this fall.....but not oak.
 
I had one chimney fire from the use of a non gasification boiler. I sold it & bought a gasser, no more creosote, no chance of a fire from same, Randy
 
longboarder2 said:
i'm thinking i can pull that off by running my dump zone more often and for longer periods of time when the temps are 30 plus---mainly because my basement dump zone doesn't have a thermostat, it's striclty controlled by the wood boiler controls. it's a basement, so it's always cooler than the rest of the house and the heat is always going to rise.

whaddya think?

It could help, but if you don't use the basement and it's not insulated you will be wasting a lot of heat.
 
we use the basement, moreso in the winter months. it's fully insulated with r-19 in the walls, which are framed inside 8" poured concrete walls.

as i mentioned before, wood is no object for me---i have access to plenty.

knowing that, in addition to the thermostatic damper door on the bottom of the unit, there are also two knobs on the fuel loading door to allow more air into the fire. by keeping these open more, will that allow the fire to burn "hotter" to keep down the creosote? or does the air "need" to come from under the fire? this all assuming i can prevent overheating by using the basement dump zone more often.
 
Longboarder2,

Could you find some Ash for wood in the next few months? Or a similary fast drying wood. Ash dries very quickly compared to most wood. It has a very straight grain, and is easy to split. Then you could let any Oak or other wood dry until the next season. If you cut, split, and stack Ash in Mar.,Apr., May of this spring, it will be seasoned for next winter. It is always better for it to go a full year or more, but Ash will get you a good moisture content in 6 months. Split it a little smaller, say 4-6" across, maximum split size, and it will be really nice to burn next season. I stack on pallets, or at least an old strip of plywood, to keep it off the ground. Try to stack it in an area where it will get sun, and some wind if you can. Do not cover the sides. You can cover the top if you want, but it is not necessary. I cover the top of the stuff I know I am going to burn first. And then it all gets moved in under a covered porch in October. Even if you can not put it all under the car port, or another cover, you can just cover the top of it before the snow flies, and that will help keep most of the water off of it. Always leave the sides open for good air flow. This would probably save you some money over buying coal or any other fuel.
 
Status
Not open for further replies.