chimney problem on new home

[firsttimer]

i bought a house this fall, and once i started making fire i noticed that my chimney leaks black water from the cleanout into my basement, i had a chemney guy here a couple of times and he cant figure out whats going on. the chimney is a clay lined brick chimney, what would cause this? thanks

 

[Trickle]

Is the chimney guy CSIA certified? http://www.csia.org/

 

[firsttimer]

i live in canada he is wett certified, hes the only one in my town, thats why im looking for help

 

[HotCoals]

Do you have a rain cap?
Getting much creosote?
Chimney on outside of house?
Some may say to line it?

 

[laynes69]

If it hasn't rained or snowed, its more than likely condensation. Modern stoves put less heat up the flue, and if the current clay liner is too large, the gasses cool to a point of condensing. We had the same problem, which an insulated liner fixed our problem. Unseasoned wood can contribute to this.

 

[Ashful]

He didn't say he was using a stove. I assumed open fireplace. Would be interesting to know what he's burning, and the flue dimensions.

 

[firsttimer]

it is a wood stove from th 80's im told, its a clay lined chimney thats 8x12, burning maple and ash thats 2 years old. no cap on chimney, vary little creosote build up been heating sinc september and its been doing it from the first week of heating untill now. im at wits end with this thing please help

 

[Trickle]

Get some pics of it and post them here firsttimer, that way folks can have a look. I get the same sort of black water leak from my cleanout (phrasing) when it rains but I know its because my chimney cap is crap. Also get pics of your chimney cap and the whole top of your chimney/flue situation so the pros here can have a look.

 

[laynes69]

Do you have a tall chimney? Yeah get a liner, preferably insulated and your problem should disappear. It takes alot of heat to warm a flue that size. When it remains cool, draft suffers and the vapors from the fire condense on the walls of the liner. I battled it for a season before I put an insulated rigid liner down our chimney. Never would I go through that again! Oh and after lining, performance increased quite a bit.

 

[pen]

What is the flue collar size on that stove? 6 inch or 8 inch?

I'm betting the large 8x12 flue size is your problem as it's a larger cross-sectional area than your stove's exit. When the gasses jump up to the larger size they expand and cool. With a large masonry chimney, it sounds like it's not getting warm enough in that chimney's flue to keep the water vapor in vapor form, so it's condensing back to liquid.

Do you have a thermometer on that stove or chimney pipe? How hot are you running things?

I'm guessing since it's leaking in your basement, that this chimney goes up through the house and is not on the outside of an exterior wall?

pen

 

[Defiant]

he is wett certified

Overqualified

 

[chimneylinerjames]

Yes you need an insulated chimney liner kit. Burn a hot fire with good dry wood and your problem will disappear, guaranteed.

 

[fossil]

Dumping that stove flue directly into an 8" x 12" chimney is at the root of your problem. I know you say you don't have a creosote problem, but the "black water" you describe is almost certainly rain mixing with creosote and running down the chimney. Has anyone opened up that basement cleanout to try to glean a little more info about the process? I say you need a chimney liner from stove to daylight, a block-off plate, and a chimney cap. The whole installation needs a careful audit/evaluation IMO. Rick

 

[Ashful]

I'm guessing since it's leaking in your basement, that this chimney goes up through the house and is not on the outside of an exterior wall?

I have had two chimneys with basement clean-out doors. One was indeed an interior chimney, running up thru the middle of a 1953 house, but the other was an exterior chimney on an 1865 house. The latter had a thimble thru the basement wall for the furnace connection, and the clean-out door directly below that.

 

[pen]

I have had two chimneys with basement clean-out doors. One was indeed an interior chimney, running up thru the middle of a 1953 house, but the other was an exterior chimney on an 1865 house.

That's why I'm asking.

 

[billb3]

Unless you run a camera down the chimney you're not going to see small cracks and imperfections in tile joints that are making your liner somewhat porous and leaky.
Unless you have a coating of creosote on the clay liner but a look-see that's usually kinda obvious.

If it's dribbling down even during an extended dry period with no rain then you have a condensation problem as well.

I'd put a rain hat on the top, make sure no rain water is getting in between the flue liner and brick/block/stone chimney shell at the top and all outside mortar joints are sound and then any water dribbling down is likely condensation .
Condensation has to be pretty bad to not dry up before it gets a chance to pool in the bottom of a chimney.

 

[CHeath]

Could you be burning damp or wet wood at too low of a temperature? That happened to me and black steamy water ran everywhere.

 

[skinanbones]

i will be another one to say get a cap for that chimney and a pipe thermometer to see what temperature you running the stove at.