Help! Smoke in our house!

[Northwoodser]

Hi,

I am reposting this with a new title as another member thought my original title lacked the emphasis to get noticed. Hopefully this is better! I got a couple great responses, with the first post, but more input would be welcome!

We purchased an Arrow 1800A woodstove a couple months ago to replace our old Earth Stove, which had developed cracks in the firebox. The stove has been great, and heats our house nicely, but every once in a while, maybe two or three times in a 24 hour period, it will emit a single, loud cracking noise (definitely from the stove, not the chimney or pipe) when it gets up around 450. We put it down to the expansion/contraction of the steel firebox, and didn't worry much about it. In the last week or so, though, it has started to emit smoke even when there is a brisk fire going (350-450). It seems to get worse when we damp the stove down. There are no visible cracks in the box, and the firebrick looks fine.

We did notice a couple of vertical cracks in our cinder block chimney facing, but we're not sure these are new. The chimney is about 25 years old with a clay liner. We have never had any problems with it, and it was professionally cleaned about 2 months ago. We have stopped building fires until we figure out what is going on. Any suggestions or advice would be greatly appreciated!

 

[Todd 2]

Hi Northwood, do you get the smoke when you first fire it up or is it after the stove has been burning a while like on a reload.
Also how is your draft with a cold stove ? when you light a match in it cold (the stove) does it draft out the chimney or push back out the open door.

Todd2

 

[savageactor7]

Hello Northwoodser, anytime you can detect the odor of smoke I would recommend 1st check for a blockage at the chimney cap.

I can't see what state your from but if your down south and the weather is cooperative then let your stove go cold and mirror the chimney to check for a blockage. As far as stove pings and bangs that's kind of normal imo.

 

[Northwoodser]

Hi Northwood, do you get the smoke when you first fire it up or is it after the stove has been burning a while like on a reload.
Also how is your draft with a cold stove ? when you light a match in it cold (the stove) does it draft out the chimney or push back out the open door.

Todd2

There is the normal (small) amount of smoke on start up, but not excessive. It is after the fire has been going for a bit and is burning nicely (around 450) that the smoke becomes really noticeable. No reloads are necessary for detection of the smoke smell. The draft seems good (it definitely goes for the chimney, not the open door) but sometimes it does seem to take a bit to get it going (like it would if there was a low pressure system).

 

[Todd 2]

There is the normal (small) amount of smoke on start up, but not excessive. It is after the fire has been going for a bit and is burning nicely (around 450) that the smoke becomes really noticeable. No reloads are necessary for detection of the smoke smell. The draft seems good (it definitely goes for the chimney, not the open door) but sometimes it does seem to take a bit to get it going (like it would if there was a low pressure system).

Did you ever get the smoke smell with the Earth stove when it was in use ?
You had the chimney cleaned 2 months ago and they seen no problems ? were they a credible company ?
After the cracking noise of the stove did the fire burn character change?
Did you add a chimney cap or any chimney changes with the new stove?
Is your chimney an interior or exterior one ?
have you taken all the fire brick out to inspect for cracks, or removed stove shields that go back on easy, inspect well the whole stove with a bright light, cracks can hide or "slight" chance of a miss welded spot but rare.
Lots of questions but just trying to cover every angle or possible reason.

Todd2

 

[ArsenalDon]

when was your flue last cleaned?

 

[begreen]

The chimney is about 25 years old with a clay liner. We have never had any problems with it, and it was professionally cleaned about 2 months ago.

 

[Northwoodser]

Did you ever get the smoke smell with the Earth stove when it was in use ?
You had the chimney cleaned 2 months ago and they seen no problems ? were they a credible company ?
After the cracking noise of the stove did the fire burn character change?
Did you add a chimney cap or any chimney changes with the new stove?
Is your chimney an interior or exterior one ?
have you taken all the fire brick out to inspect for cracks, or removed stove shields that go back on easy, inspect well the whole stove with a bright light, cracks can hide or "slight" chance of a miss welded spot but rare.
Lots of questions but just trying to cover every angle or possible reason.

Todd2

Todd2,
We never had any problem with smoke in the house when we were using the Earth stove.
The chimney cleaners were recommended to us by an area realtor and friend of ours who uses them for her own house and recommends them to clients, so I assume they are reputable. They did not see any problems beyond a minor and normal creosote buildup in the the chimney, which (they said) they removed.
The cracking noise was not followed by any changes in the fire burn character. That is part of the reason it didn't initially concern us.
We do have a chimney cap, but we used it for 2 years with the Earth stove prior to getting this stove and had no problems. We have made no change to the chimney. The stove pipe is new this year, but I would think that would go in our favor.
The chimney is interior.
Yes, I have removed the firebricks, and the firebox walls behind them all look sound. The heat shield cannot be removed, and the sides are welded on, so the interior is the only place that can be easily inspected.

Thanks for any suggestions!

 

[Northwoodser]

when was your flue last cleaned?

The flue was cleaned 2 months age, at the same time as the chimney.

 

[mfglickman]

Is it possible it's backpuffing? You say it's worse when you damp it down - in certain conditions my stove will backpuff if I've damped it down too quickly...then a puff of smoke comes into the room.

 

[begreen]

Good call. I was wondering the same thing. Is the smoke leak steady, all the time or was that loud sound you heard a backpuff?

Back-puffing results when the fire produces volatile gases (thick smoke) faster than the chimney draft pulls them out of the firebox. The gases back up in the firebox till they're dense enough and hot enough to ignite. If your stove back-puffs, you should open the damper to let the smoke rise to the flue more quickly, let more air into the firebox, and avoid big loads of firewood. You should always see lively, dancing flames in the firebox; a lazy, smoky fire is inefficient, can lead to back-puffing, and can contribute to creosote buildup in the chimney.

 

[Todd 2]

What size is the inside of the clay liner in the chimney ?

 

[Northwoodser]

I wondered about backpuffing, too, but the cracks are only heard when there is an established fire going. The damper has been open wide when the cracking sound has occurred a number of times. I do wonder if the draft is strong enough sometimes, as it can be difficult to get the fire up to temp. We leave the damper open, though, until it is up to temp. This can sometimes take an hour or more, but we put this down to weather conditions (low pressure, etc.).

I don't know the exact measurements of the inside of the clay liner, but if memory serves, it is either 6" or 8". I would check, but our house is two stories with a goodly pitch and there is a foot of snow on the roof . (We live in Wisconsin.)

 

[begreen]

When you say you leave the damper open, is this a pipe damper or the air control? You might be able to measure the flue tile size via the cleanout door? While you are there, make sure that door is sealed up tight when closed. If it can't, duct tape it shut.

 

[Northwoodser]

Both, usually, but the air control is small (a tiny grate under the door on the front of the stove), so most of our control comes from the pipe damper. When one is open, the other is usually open as well. They are always both open when we are establishing a fire.

The cleanout is in our crawl space. I hate it down there, but I will prepare myself and go down. Spiders give me the willies...

 

[begreen]

Look on the bright side, spiders are better than rattlesnakes down there. Bring a tape measure and a roll of duct tape with you.

 

[Northwoodser]

So true!

 

[Northwoodser]

Alright, so I went down to the cleanout, and found a moderate amount of creosote in the cleanout, which I removed. The inside of the liner measures 6". There was no cleanout door, just an opening in the chimney. Eek! I have never been down there, relying instead on the chimney cleaners/inspectors to tell me if something was amiss. I guess we'll be looking for other cleaners... Could the lack of a door be part of our drafting problem? I duct taped a piece of sheet metal over the opening, so it is now sealed. There were also vertical cracks in the cinderblock exterior above the cleanout.

I re-examined the firebox and firebricks when I got back upstairs, and the firebox still checks out, but 5 of the firebricks have hairline cracks in them that I hadn't noticed before, and one actually broke in half when I set it on the floor. Would this be the source of the cracking sounds we heard? If so, is it excessive heat causing this to happen? We have never run the stove over 500, and that was only briefly. Mostly we try to keep it around 450. What can we do to prevent this kind of wear on the bricks in the future?

 

[Northwoodser]

Okay, the news get better. I took the pipe that connects the chimney to the stove off to check it for creosote, and discovered a huge zig-zag crack in the clay chimney liner that extends as far as I can see in both directions. It doesn't look new, though. There is creosote that has stuck to the edges of the crack from the stovepipe opening up. There is also creosote that has formed between the liner and the cinderblock. Yikes! It looks like the installers didn't seat the pipe properly when we had the new woodstove installed. So... Is it possible to drop a stainless liner down inside a 6" clay liner, and if it is, would it cost more than it is worth? Our chimney is close to 35' tall from the crawl space to the top. Thanks for the input.

 

[chimneylinerjames]

It is possible, not the easiest but possible. You can use a 5.5" liner, that would be 5.75" OD. The liner will only need to extend down to the thimble area, where it hooks up to the stove, not all the way to the ground. They are usually simple enough that a homeowner can install the chimney liner. I would recommend using a rope tied to the end of the liner and have someone pulling on the rope as you twist the liner down.

 

[Todd 2]

As for the fire brick, they make a fiew different grades of them, your stove might have come with the lower quality ones, its a cost effective thing for the builder. I would just replace them as they brake, it will not hurt to use them cracked for a short time, I dont think the bricks are making your cracking sound though. Maby the metal in the stove heat pinging since the baffle is welded in steel.


No clean out door is a big problem, that is your draft problem and leads to fast creosote build.
Is the door missing, rusted off, gone ??? Fire your chimney sweep, sounds like a "Chuck in a Truck" company.
As for the chimney sounds like possibly SS liner time, a 6" flex liner is like 6 3/8" + on the outside so it might not fit.
However I have heard of people installing a 5 1/2" with that height and central wall chimney you should still get a good draft.
Several people on here have a central non insulated liner and they work great for them.
As far as cost vs worth, it all depends on how much the wood heat saves you, most cover the costs rather quickly depending on your primary heat source.

Lets see what some others think.

 

[MasterMech]

IMHO, that clay liner sounds like it's finished. I'd be all over dropping a stainless liner down the chimney.

 

[Northwoodser]

As for the fire brick, they make a fiew different grades of them, your stove might have come with the lower quality ones, its a cost effective thing for the builder. I would just replace them as they brake, it will not hurt to use them cracked for a short time, I dont think the bricks are making your cracking sound though. Maby the metal in the stove heat pinging since the baffle is welded in steel.


No clean out door is a big problem, that is your draft problem and leads to fast creosote build.
Is the door missing, rusted off, gone ??? Fire your chimney sweep, sounds like a "Chuck in a Truck" company.
As for the chimney sounds like possibly SS liner time, a 6" flex liner is like 6 3/8" + on the outside so it might not fit.
However I have heard of people installing a 5 1/2" with that height and central wall chimney you should still get a good draft.
Several people on here have a central non insulated liner and they work great for them.
As far as cost vs worth, it all depends on how much the wood heat saves you, most cover the costs rather quickly depending on your primary heat source.

Lets see what some others think.

Sounds like a good analysis for the firbricks. I will look for a better grade.

As for the cleanout door, it doesn't look as if there ever was one. There is just a rough round hole knocked out of the cinderblock. There was some fiberglass insulation at the bottom, so it almost looks like the previous owner tried to plug it that way(?!). We're lucky the house didn't burn down!

I should explain the cost question. We were thinking of switching to a pellet stove for our primary heat this coming heating season. We have about 7 cords of dry wood split, stacked and ready to go, though, so we wanted to use that first. Replacing the stove cut into our burn time this season, and now with the chimney a goner without a new liner, we are just wondering if we should cut our losses and try to sell the stove and wood. I honestly don't have any idea how much a SS liner would cost for our purposes, but I know steel is pretty pricey right now. So that is our dilemma. If it's not too astronomical, it would be nice to have the woodstove as a backup/supplement to the pellet stove, though...

 

[Northwoodser]

It is possible, not the easiest but possible. You can use a 5.5" liner, that would be 5.75" OD. The liner will only need to extend down to the thimble area, where it hooks up to the stove, not all the way to the ground. They are usually simple enough that a homeowner can install the chimney liner. I would recommend using a rope tied to the end o the liner and have someone pulling on he rope as you twist the liner down.

That doesn't sound too bad. At least we can cut about 15' off the length of the liner!