First Time Wood burner had a Chimney Fire; couple questions now.

[Beetman]

Let me start with the background information. Moved into a new house in July and the previous owner had a Dutchwest Extra Large 2462 that he used for heating. The stove was vented into a 12x12 masonry chimney lined with clay. He also left behind ~3 cords of stacked and covered mixed hardwoods. I had the chimney inspected early in the fall just to be safe, and the sweep found numerous cracked tiles and suggested lining the chimney.

So I had a 30' 8" stainless liner installed (stove manual reccomends an 8" flue) and began burning wood regularly. The Dutchwest proved to be a very finicky stove, and I quickly learned that if I had the catalyst bypass open for too long while getting the fire going, flames would roar up the flue and get the liner glowing red quickly. Engaging the catalyst would be enough to get things under control. By early December I had the hang of operating the stove and was burning round the clock. On weekdays I would fully load the stove once in the morning and once at night. On weekends, I might load the stove twice during the day and once at night. Most times I was reviving a meager coal bed.

Then I had my first chimney fire. It burned for about 15 minutes with all air controls fully closed. I figure it was relatively small as there were no flames or debris coming out of the chimney top. To be safe, I had a sweep come out (different from who installed the liner, I wanted a second opinion). He verified there was a fire, swept the chimney and deemed it still safe to use. However this is were things get murky, as he gave me some "interesting" advice.

He said the excessive creosote build up was due to me fully loading the stove. He said never load more than 1 piece of wood at a time, even if it means loading all night long. He also said never engage the catalyst as it will damp the fire, increase the amount of smoke and thus creosote. At this point, I just nodded politely and figured it was time to ask the internet for help.

So what is the likely cause of my excessive creosote build up? Is it bad technique? Burning poorly seasoned wood? I did buy a moisture meter and tested ~25 logs and found most to be about ~12-15%. A few pieces from the same tree read 20-21%.

I haven't used the stove since the fire (it was scary as h*ll!) and I am reluctant to do so until I figure out my problems.

One final question: The chimney sweep removed the mesh spark arrestor/animal barrier as it was caked with creosote. Is it safe to burn with out this? My fear is large chunks of burning creosote flying out during a chimney fire and lighting my roof on fire.

Sorry for the lengthy first post, I didn't want to leave anything out, but I'll expect a few "tl;dr"s.

Thanks for any help in advance.

Cameron

 

[bholler]

Well he is just plain wrong. When you tested the wood did you test it on a freshly split face? It is probably ok to burn without the screen lots of caps don't have them on from new but some areas require them.

 

[Jags]

The second sweep appears to be misinformed. Loading the stove, charring, and adjusting the primary controls for the long haul is commonly referred to as "batch" burning and is the preferred method for many.

What good is a cat if you don't engage it?

Your fuel - when you tested for MC, was it on a freshly split face?

Once you get the stove settled in for the long haul - do you see smoke out the pipe?

A flue fire is creosote - obviously. Ya need to figure out the reason for the accumulation. Generally:
Start with the fuel - is it dry
Draft - are you allowing enough draft to maintain proper stove operation (not smoldering)
Operation - Does your method of operation put you at risk for generating creosote? (kinda the same this as draft but there can be some subtle differences like stalling the cat, dirty cat, etc.)

Burning without the screen isn't a deal breaker, but I added one to my stack (dang birds).

 

[mellow]

Did you measure a fresh split piece on the inside middle to get your %? Most of the time this is due to unseasoned wood. The cat on your stove might be bad as well.

Don't listen to the sweeps advice, doesn't sound like he knows what he is talking about.

 

[Dustin]

Your burning methods are very similar to mine, minus the catalyst.

What's the condition of the cat? Is it toast? This could be causing it not to function and allowing excessive creao to build up. I'm sure the cat guys will chime in shortly.

Is your liner insulated? 30 feet is a ton of liner to keep warm. Exterior chimney?

 

[shoot-straight]

have a cat and not engage it... no way

one piece at a time... no way

for sure find a new sweep.

modern woodstoves are designed to complete a "burn cycle". that wont happen one piece at a time. how did you know your liner was glowing anyway? get the stove up to temp then engage the cat (might need a new cat). the cat is designed to eat up that smoke. find a decent dutchwest dealer and speak with them. but first, google dutchwest and find an operation manual for that stove.

 

[Beetman]

The moisture meter was used exclusively on fresh split faces. However, there were piles of wood were spread all around the yard, where the previous owner had dropped trees. So I don't have any wood left to test from some of the first piles I burned.

As far as smoke out the chimney, with the fire fully underway and the catalyst up to temp, there was virtually no smoke out the chimney.

However during reloads, there was plenty of smoke which I attributed to not having the cat engaged. Since I was starting from a small coal bed, it would regularly take 45-60 minutes to get the wood burning and the cat up to temp. My cousin thinks this might be the problem, and that starting with kindling before adding larger splits might reduce this time and the creosote production.

The catalyst looks ok, a few chips missing here and there and I was planning to replace it next year. However from everything I've read it is operating correctly. It gets up to the proper temps, reduces smoke to a minimum et cetera.

The liner is insulated, and this is not an exterior chimney. It is at the center of the house so only the last 5-6 feet are exposed. I have good draft, no problems with smoke coming back into the house when starting with a cold flue.

I have the manual for the stove, and follow the operating instructions.

Thanks for all the quick replies!

 

[Jags]

Your cousin might be on to something there. 45-60 minutes does seem to be a bit excessive to me. As a comparison, I go from cold stove to 550F stovetop in less than 35 minutes every time - easily. I would be finding a quicker method of re-lights. The delay could also be sub-par fuel.

In any case - I would be working up a plan for more frequent inspections/cleaning. If there isn't fuel to burn - there will be no flue fire.

 

[tcassavaugh]

.......yup, sweep #2 should stick to sweeping and quit giving advice about burning. I don't think I would trust his work after a statement like he made. not sure where he came up with his credentials. is he certified? anyway, sounds like it might be wood related. I had an Adirondack and the 2461, the 2461 is currently sitting in the basement.....I liked both stoves, I had to upgrade and get a bigger stove so I went to the pe summit freestanding. my experience with the 2461, the little brother to yours was that it needed good wood but yours sounds like its been seasoned awhile. the cat would occasionally quit and i'd have to pull the top and clean it out. all in all, it was a pretty good stove. I don't really remember any runaways with the stove or it "roaring up the flu" and getting the pipe red. you might want to check your gaskets. or, check the door as it might need a little tightening. just a thought. dry wood is the big thing for sure or else it will produce creosote like a factory.....or, at least that was my experience. i'd do the chimney every couple of months.....because I wasn't burning real good wood back then.

 

[Nick Mystic]

There seems to be some inconsistencies in your wood burning description. You said it took you 45 - 60 minutes to get your reloads going and that your cousin said that might be causing excess creosote build up, which makes sense. But you also say you were starting fires with your bypass open too long and you were getting your liner to glow red hot. Do you see how these two statements are exact opposites? No way you can be getting creosote building up in your flue if you are running so hot your liner is glowing red hot! However, the proof is in the pudding and if you had a lot of creosote and then a chimney fire then you must be burning some smoldering fires with sub-par wood. I would recommend working on getting a good fire going in 15 - 20 minutes. I'm not familiar with your stoves burning characteristics, but with some stoves you have to keep the door cracked awhile on start ups to establish the fire. The suggestion of using smaller kindling on reloads to get things going faster is a sound approach. When you reload with large splits on a modest or small coal bed it can take as long as the 45 - 60 minutes you mentioned. You don't want that going on for sure and it is probably where your creosote build up came from.

 

[woodgeek]

"The cat gets up to proper temps"...could you be more specific? Loading a chimney with creosote with a cat stove? I still suspect the cat, esp given the source of the stove...was it a 'slammer' install or did the previous owner have some pipe in there?

 

[Creekheat]

This was a very interesting thread. As im a new burner its good to hear specifics about burning wood.

 

[Charles1981]

I guess I would like to know more about the chimney fire you had. You said there was no flame or debris coming out the liner. What happened with the chimney fire? What made you suspect there was a fire? Did the sweep tell you what signs he saw that made it a give away that you had a chimney fire?

And do not listen to his advice on how to run that stove. It makes absolutely no-sense. The way you were running the stove previously sounds mostly appropriate other than letting the liner glow red. That is bad.

 

[Beetman]

Let me try and address all the questions:

"The cat gets up to proper temps"...could you be more specific? Loading a chimney with creosote with a cat stove? I still suspect the cat, esp given the source of the stove...was it a 'slammer' install or did the previous owner have some pipe in there?

There is a probe thermometer on the stove top that monitors the catalyst temperature. It would regularly read about 1000 degrees during typical operation. Not sure what you mean by "slammer install". However that previous owner had about 10 feet of "liner". It was stainless pipe that was deformed to fit through the hearth flue opening.

I guess I would like to know more about the chimney fire you had. You said there was no flame or debris coming out the liner. What happened with the chimney fire? What made you suspect there was a fire? Did the sweep tell you what signs he saw that made it a give away that you had a chimney fire?

Several clues. The liner and connector were glowing red, there was a "raining" sound coming from the liner (I've been told this was creosote) and a roaring sound of air being sucked into the chimney. I had all air controls on the stove fully closed and the liner stayed red for 15 minutes. The sweep did not tell me what clues he found to indicate a fire.

There seems to be some inconsistencies in your wood burning description. You said it took you 45 - 60 minutes to get your reloads going and that your cousin said that might be causing excess creosote build up, which makes sense. But you also say you were starting fires with your bypass open too long and you were getting your liner to glow red hot. Do you see how these two statements are exact opposites? No way you can be getting creosote building up in your flue if you are running so hot your liner is glowing red hot! However, the proof is in the pudding and if you had a lot of creosote and then a chimney fire then you must be burning some smoldering fires with sub-par wood. I would recommend working on getting a good fire going in 15 - 20 minutes. I'm not familiar with your stoves burning characteristics, but with some stoves you have to keep the door cracked awhile on start ups to establish the fire. The suggestion of using smaller kindling on reloads to get things going faster is a sound approach. When you reload with large splits on a modest or small coal bed it can take as long as the 45 - 60 minutes you mentioned. You don't want that going on for sure and it is probably where your creosote build up came from.

I should have been more clear. The glowing liner while lighting was a rare occurrence that happened to me early on when lighting the stove. What would happen is a piece or two of wood would start burning fully yet the whole load wouldn't be consumed with flames. (this is a pretty large stove, it will take quite a bit of wood). The strong draft would draw these flames up into 90 degree connector and the liner. To avoid this I would sit by the stove and carefully monitor the primary air to make sure things didn't get out of control. To get the whole firebox full of flames starting from a small coal bed would then take about 45-60 minutes.

I'd like to start burning again, but this time with a new reload approach. Some kindling and small splits to get things going, then larger splits for an extended burn. I'm starting to think my problem is two fold. Fully loading the stove on a weak coal bed which was giving me slow, smoldering relights. As well as poorly seasoned wood. I can't verify this, but I have found some pieces to have high moisture content so its plausible.

The previous owner left his chimney brushes, so maybe I can run the brush through after a week and two and see what comes out.

 

[JA600L]

Get a bag of wood pellets. Sprinkle the pellets over the hot coals. Get the stove up to temp, throw in some kindling, make sure that's going strong... Then throw your big pieces in. I never ever throw big splits in until I am sure my flue is properly warmed up. Even at 18 percent moisture, you can still make creosote. You need to warm the entire flue above 260 with the driest fuel possible.

 

[Charles1981]

If the liner truly is "ok" (and i don't think anyone here is too happy with the information the sweep gave you regarding how to burn properly) I would start burning again.

But you never want smoldering, your never want a glowing liner, and if you can't get up on the roof and sweep the chimney once a month you are never going to truly know whats going on inside that liner nor be safe that another fire won't occur.

If you can clean out and measure the creosote each month, you can start to understand more how your burning practices are affecting whats going on inside your liner and keep yourself that much safer.

 

[Backwoods Savage]

Welcome to the forum Beetman.

I won't get into much because there has been so many answers already; most good. But I will say when you are starting a fire in a cold stove, it is common to have to turn the draft down early to avoid what happened to you. With our stove, when starting cold, it is common to have the draft open fully but not for the whole time. Perhaps 10-15 minutes maximum and then we'll cut to 50% draft at most; sometimes even lower. What happens is with the bypass open, most of the heat goes right up the chimney. For sure you need to get the chimney warm but not hot. What you really want to happen is to get the stove hot enough so that you can close the bypass and then let the catalyst work. For what it is worth, if we are starting with a cold stove, we do not fill the stove! Usually 2 or 3 splits along with a couple pieces of kindling works well. We can get the stove top temperature high enough to engage the cat. Then on the reload, if we need the heat we can then fill the stove. But by no means do we always fill the stove. The amount of wood and they type of wood is determined by the outside temperature and what the forecast calls for. For sure if the outdoor temperature will be in the 20's, we don't need a full stove but if it is to be a real cold night, then it gets loaded with the best wood.

On reloads, most times we can engage the cat within 10-15 minutes; some times less and some times more. We want most of the wood to be charred before engaging the cat. When the cat is engaged (bypass closed), we do not turn the draft to our normal operating spot but instead will usually set it between 25-50% and then after another 10 minutes we can cut the air a lot more. How much will depend upon your stove.

For sure from what I've read, I have to say the fuel is your biggest problem. Your second biggest problem is in choosing chimney sweeps. You surely had a loser this last time! Because of his lack of knowledge on running a stove, I would also question his knowledge about sweeping the chimney too.

Good luck.

 

[weatherguy]

the 2nd sweep was probably used to burning an old stove, I noticed a lot of people I come across with older stoves burn one piece at a time. My BIL has 2 newer Englanders a that's how he burns, throws one split in the stove every now and then. Not sure why they do it like that other than their fathers & grandfathers did it like that

 

[clemsonfor]

The purpose of a catalyst stove is to "smolder" the wood to produce smoke so that the cat can eat and produce heat. The catalyst if fully functioning will burn 90% of the smoke and remove the creosote particles.

 

[clemsonfor]

I would also say the wood and cat. Unless you have massive splits it should not take 50mins for 20% wood to become engulfed in flames even my biggest splits do though really in 20-30 mins max.

A bad cat can still easily read over 1000f all the fire heat is going through it and certain times it will read that. How do I know. My cat failed early last season. I consistently saw temps over 1000, saw a bit of smoke all the time though all though it did clean up some engaged, bit by the end of the season my chimney was 60% plugged up top. And last year I had better fuel than the year before which I barely had more than powder at the top of my chimney. This year almost 2 cord burned and although I have the coffee ground looking stuff stuck to the metal cap it looks like almost nothing in the flue. Oh I replaced my cats before this season.

 

[Beetman]

I figured I should add some sort of meaningful conclusion, so here goes.

I inspected the cat after a few posters flagged that as a possible source of trouble. Sure enough it was in rough shape; multiple cracks, sections crumbling et cetera. I ordered a replacement which arrived last night, and I am back to burning.

I think my problem may have been a perfect storm of sorts. Bad cat, poor reloading technique, and the occasional load of unseasoned wood. I'm going to finish out the year, buy a sooteater and clean the chimney in a couple weeks to see how much buildup I get.

Thanks for all the help!