Need help... bad soot/ash problem, possibly caused by overfire?

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KSgrown

Member
Dec 1, 2010
80
Kansas City
We have a Century CW2500 in a masonry fireplace going on our 4th year. The first 2.5 years it went very well but in the middle of last season we starting having a very bad problem of large volumes of very fine ash through out our entire split level home. It was sticking to anything plastic, mainly noticeable in the kitchen on tupperware and the like, even if the cabinets weren't opened. It was in the air stream throughout the house, causing a noticeable haze at times. It came and went, worse some days than others. It killed the fan on a humidifier and would clog my furnace filter so bad that it would shut off due to high temp because of lack of airflow, the filter was caked with ash. It would cake up in 3-4 weeks.

See this post I made before last year about our fuel... very old hedge fence posts. It made great heat but I fear that it (i.e. me) overfired our stove and popped a weld, possibly causing this problem.
https://www.hearth.com/talk/threads/worried-about-my-hedge-stack-please-advise.90412/

It's been 1 week worth of burning this year and the symptoms are returning... we haven't even scoped ash yet this year and I've already had to replace a furnace filter from ash buildup.

We can't use the stove like this and I'll have to decommission it until we determine the problem and hopefully fix it. Can we fix it? Is it ruined? The CW2500 is not a high quality stove to begin with... maybe it couldn't handle the hedge?

Thanks for any feedback...

Threads I used for reference that sound similar:
https://www.hearth.com/talk/threads/evidence-of-air-polution-in-our-house.65066/

Doug in KC
 
Sure sounds like a major crack in the firebox or flue disconnected or partially blocked somewhere. not familiar with that stove.
 
Sounds like a pipe disconnected. Can you pull out the insert and look up, a pain I am sure but you gotta figure this out. Can you run a brush from top to bottom?
 
Pull the stove and look it over. I think it's a steel box so it should be able to be welded if there's damage. A little bit of smoke in the house on startups isn't uncommon, but you shouldn't get ash everywhere.
 
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Gonna sound stupid but.... when was the flue last swept?
 
I certainly wouldn't burn that stove again until you figure out and solve the problem. If you are living in the house with enough ash in the air that is blocking off your furnace filter then think what you lungs must be going through! Those fine ash particles are particularly bad to breathe due to the fact that they penetrate so deep into the lung tissue. If I had that problem I would start a fire at night when it's dark outside and then while wearing a respirator I would use a high intensity spot light to look the stove and flue system over. A spot light should be able to see where the fine ash is exiting the stove - think about a spot light shining in a smoke filled night club. Once you find the leak you are on your way to fixing the problem.
 
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Typically, an unexpected hole/crack/opening in a stove firebox isn't going to fill your house with ash or anything else, unless your setup doesn't draft. Such an opening would typically be sucking air into the stove, not pushing anything out.
A house filled with ash has to do with how you reload a hot stove or empty ashes when cold. If there is a flue pipe disconnect problem, then you'd also be filling your house with smoke, so that's probably not it.
Some pictures of your setup might help.
 
We never have a problem with ash- just a little bit in the stove room, but that is to be expected. I would say you have a draft problem and the ash os flying out of the stove when you reload. If you had a crack in the stove large enough to leak that much ash into the room, your fire would be completely out of control and the stove would probably turn into a molten puddle.
 
A while back we had a lady that had serious complaints about ash all over the house. It turned out that they were cleaning ash out frequently with the blower still running. The stove had a shallow firebox and no ash lip which exacerbated the issue.

How frequently does the stove get cleaned for ash build up? Do you have the blower off when cleaning out ash?
 
That makes sense to me- I have made the mistake of cleaning ash with the blower on a couple times, and that will definitely get a lot of ash flying around in a hurry. And a faceful of ash...
 
Sorry for no replies or updates.. I was looking for an email but hadn't gotten any and anyway... I'll update and help troubleshoot the questions.

More info... the problem from 2011 due to ash was not the same thing. That was the typical learning curve deal where burning wood is messy and if you don't clean up the occasional minor ash fallout during reload, it gets caught in the blower and makes the stove room dusty. We went through that and I put a charcoal filter on my blower intake and solved that problem. This is completely different than that, this is not ash in the traditional sense, more like makes a film on the windows, very fine particulates that you don't notice until they get caught, almost like how spray paint acts, you don't really see it but if you have a fan and filter for it, you sure catch a lot of tiny particles. This stuff isn't really settling like ash does, it stays in the air until it sticks to something with a static charge or gets caught in a filter or builds up near an air intake, like a computer fan or room humidifier fan.

The house never does smell like smoke and the monoxide detectors haven't shown any indication of a CO problem. But, I do agree that this is very bad for my families health and we will not burn until I feel like I found the cause.

This stove has a steel firebox inside of a steel outer box . I don't have direct access to the exterior of the firebox because of the way this stove is built. I agree with almost every post here... I have a hard time believing this problem is being caused by a crack in the stove, if there is one, which has not been confirmed. Also, we've only been burning for 1 week here, I haven't even scooped ash this season, so we can rule out a sloppy scoop causing this. I also feel like the problem happens in the morning after a burn when there is still enough coals to start a new fire but there probably hasn't been a flame is 4-6 hours.

I have a 25' masonry chimney on the North side of the house. I installed a 6" flexible stainless flue that was ovalized to ~5x7 to fit through the smoke shelf. It is insulated and I have a block off plate at the bottom. I have many pictures of the installation.

I'm beginning to wonder if my stove to flue connection is the problem. This stove has an awkward connection because the top back corner is chamfered such that the flue outlet is at a 45. The way my flue pipe comes down, there isn't much play and making that connection was difficult. I remember not being 100% happy with that connection and I used a bunch of fire caulk or fire sealant to put around that connection to make sure there wasn't any opening. It's possible that there is a small opening there. I was concerned about this during installation but read on here that while burning the flue will be negative pressure so a small opening there will only draw air up the flue and not cause a problem.

I stuffed the flue tonight to prevent down draft, pulled the surround and did some investigating with a flash light and a mirror. I could not find any broken welds in the fire box.

Should I pull the stove and look it over or disconnect the flue and reconnect, making sure it's a better seal?

Any more advice or questions are welcomed. Thanks for the replies, it helps a lot.

I also noticed that I have this documented problem on one side, a broken tack weld. I have the newer version of the stove than this person and I don't believe that this affects operation of the stove:
https://www.hearth.com/talk/threads...-dw2500-or-century-hearth-cjw2500.5931/#82345
 
Also, I clean the flue from the bottom with a Soot Eater and I thought it worked well but this is my first wood burning stove. I last cleaned it at the start of the 2012 burning season. I intended to clean it for this season but the thought of the fire was too tempting when we had the cold spell here in KC 2 weeks ago. This will also be on my list to-do this week. I burned all hedge last year with hot fires all season so I felt like my creosote build up would have been minimal. I am sure this is a big no-no on the site.
 
Gonna sound stupid but.... when was the flue last swept?

This keeps running through my mind.... hard to imagine that this would be causing such a huge issue... I need to do this tomorrow night first thing.
 
A visible haze with no distinct smell of smoke? A fine film over everything? What did you insulate the liner with? Is there a chance something is heating up in the attic like some kind of insulation and somehow becoming aerosolized (that would be terrible). I would get that chimney inspected at every inch inside and outside.
 
I feel like I'm describing it bad... it is like that but it's not over everything like dust would settle, it stays in the air. Although it did make a film on the windows of the stove room.
The flue insulation came with the liner and it's installed in a masonry chimney lined with clay tile that was inspected 5 years ago too be good for regular masonry fireplace use.
Also, it is actually ash (or maybe soot?), just very fine particles. I know that because I see and feel it on the furnace filter and I clean out the air purifier filter with my air compressor and it comes off like dust would.
 
I wonder if your liner might have opened up or broken loose up top.
 
If you had trouble connecting the liner to the stove a 15 degree elbow might have helped. There's quite a few threads on here with people that have done this.
 
I used to have an old insert in my living room and I routinely cleaned fine ash of the grates in front of where the the heated air from the blower exited the insert. I assumed that somehow the ash from the stove was entering into the area between the firebox of the stove and the outer layer, but there was never enough of a problem to worry about. I'm not sure how you would check for this problem beyond scanning the inside firebox extremely carefully for small cracks.
 
Did the problem only manifest itself with the hedge posts? Are the stove flue and furnace flue in close proximity to each other - could this be a factor? Negative pressure in house when stove is running, hedge making lots of "sparks" & sending a few embers up the flue. The house sucking some exhaust / ash particles back down the furnace flue perhpaps? A bit of a stretch - or does any of this even make any sense at all...?
 
Did the problem only manifest itself with the hedge posts? Are the stove flue and furnace flue in close proximity to each other - could this be a factor? Negative pressure in house when stove is running, hedge making lots of "sparks" & sending a few embers up the flue. The house sucking some exhaust / ash particles back down the furnace flue perhpaps? A bit of a stretch - or does any of this even make any sense at all...?

Yes to the hedge posts but the furnace flue is not in close proximity to the chimney, and with the stove flue being 25' tall and the furnace flue ~30' I don't see that as being the problem. But I did understand what you were getting at and it does make sense.

Although, I do wonder if the house goes negative and draft doesn't hold on while the final coals burn out, leading to this problem. But again, we don't smell smoke and the CO detectors does register this as being a problem.
 
20131202_195500_zps8407fcc7.jpg


No blockage from the top. Going up from the bottom next
 
I did some investigating tonight. I got on the roof, checked for blockage and proper flue to cap connection and attempted to take a picture looking down the liner. If you look real close, you can actually see the joint in the liner. Everything looked intact and connected properly. Next I scooped out the ash from the last week or two of burning (we don't burn everyday) and swept the liner with the Soot Eater, from the bottom up. More creosote came out than I expected but I didn't suspect any blockage or have any trouble sweeping. I cleaned out the firebox and did my best to inspect the entire stove for damage, none found. I shut off the lights in the room and put my LED torch light in the insert, at the connection to the liner and checked for light coming out; I couldn't see any light shining through and could not see any openings in the insert to liner connection when inspected with a light and mirror so I could see the back side. I took the blower off and got access to the entire bottom of the stove and could see up the back side with the mirror, no visible damage found.

Please review my (20) photos on Photobucket, album is located here:
http://s600.photobucket.com/user/dnorman65/library/Fireplace?sort=6&page=1
(please let me know if the link doesn't work) Pictures include installation in 2010 and pictures from today.

My wife is questioning the door and window gaskets.. could a bad gasket cause this problem? I don't think they look bad but then again I haven't seen a bad one. They are 3 years old and we don't burn everyday and usually only in the evenings. Gasket pictures are in the album linked above.

The insert to liner connection is one of my last ideas for a source of this problem but during investigation, the integrity of the connection actually looked better than I remember. But I will admit, it is very ugly. I'm thinking of breaking off all of the sealant and starting over with this connection.

Another idea is maybe my house goes negative and when the stove only has coals, it downdrafts? I don't know this is happening but at this point I'm at a complete loss and have no idea what is causing my problem. I can't find any cracks or damage to the insert. The flue connection looks OK and is confirmed to be clear and connected properly to the chimney cap.

Any ideas for me to try?? We probably will not use the stove this year based on not finding a source to the problem and keeping my families health and safety first.
 
A house filled with ash has to do with how you reload a hot stove or empty ashes when cold.

Could I really be reloading poorly enough to cause this big of problem? Is there some sort of proper technique that I'm missing? We didn't have problems for 2 years. Also, typically air is being pulled through the stove when I reload, so please explain if there is something I'm missing with proper reloading.
 
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