8 inch stove flue to 6 inch chimney

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thekolmans

New Member
Feb 4, 2011
9
Canon City, CO
This is my first stove I have ever bought and installed, so everything is very new to me. I just bought a used Consolidate Dutchwest FA288CCL. Our house has a 6 inch chimney liner already installed (only about 3 years ago, from my understanding. We moved in just this past August) that was used for a wood burning hearth stove that was taken out by the time we moved in. Our new stove has an attachment that comes from the stove (it's a rectangle opening from the stove) and transitions into an 8 inch round. Am I able to install a simple 8 inch to 6 inch reducer in order to connect to the chimney liner, or is something else needed? Thanks!
 
I'm not familiar with your stove but the VC encore 2550 can be run with the optional 6". The down side is you can not burn with the front doors open for viewing the fire.
Hopefully others familiar with your stove will chime in.
Good luck.
 
thekolmans said:
Why would you not be able to open the doors? Is it for draft reasons?

Flow volume reasons. A 6" flue with doors open moves half the air of an otherwise identical 8". Your greatest risk is smoke rollout on reloads.
 
I have a new Defiant install with 17' of 8" pipe and cannot realistically see running the stove with a screen and doors open, which was the only reason I went with 8" in the first place. The draft is to strong and would cause a very strong fire and over cooked flue pipe temps. The only way I could see to do it, at least with my setup, is build very small fires. I must admit however I am new to wood burning and this is my second stove. YMMV
 
barrettdp said:
I have a new Defiant install with 17' of 8" pipe and cannot realistically see running the stove with a screen and doors open, which was the only reason I went with 8" in the first place. The draft is to strong and would cause a very strong fire and over cooked flue pipe temps. The only way I could see to do it, at least with my setup, is build very small fires. I must admit however I am new to wood burning and this is my second stove. YMMV

It sounds like you have too much flow, not too little. This is the better problem, since it's pretty easy to get rid of flow/draft. :)

Consider installing a stovepipe damper, which will allow you to dial down your draft and see if that helps.

HTH, and good luck.

PS: Still the cutest stove photo ever.
 
(Curious) George said:
thekolmans said:
Why would you not be able to open the doors? Is it for draft reasons?

Flow volume reasons. A 6" flue with doors open moves half the air of an otherwise identical 8". Your greatest risk is smoke rollout on reloads.

Yes, that and you might not be able to get the max heat out of the stove when you really need it. Volume in = volume out, so if you need "X" amount of combustion air for the highest burn rate but your chimney can't vent at that rate, you will be air-limited by default, no matter how much wood you load or how much you leave the inlet damper open.
 
Internal or external chimney? Do you have the manual for your stove, if not it is available online.
 
Outside of needing to keep the doors closed, does reducing to 6" from the 8" stove flue seem okay? Here's another thought- is it feasible to take the liner out, send a 5 foot section of 8" pipe up the chimney (which I have), and use the rest of the chimney without any liner or pipe?
 
barrettdp said:
I have a new Defiant install with 17' of 8" pipe and cannot realistically see running the stove with a screen and doors open, which was the only reason I went with 8" in the first place. The draft is to strong and would cause a very strong fire and over cooked flue pipe temps. The only way I could see to do it, at least with my setup, is build very small fires. I must admit however I am new to wood burning and this is my second stove. YMMV

Really? Not doubting you, but have you actually measured your pipe temps? I have a Vigilant with 25' of 8"x8" square tile chimney, and the draft is very powerful. I don't often burn with the doors open since the stove is in the basement and we don't hang out there, but I never get real high flue pipe temps with the doors open. Just the opposite, really. If I got a decent load going in the stove (1/3 full) with the doors open and then closed them, the flue temps would soar unless I shut the inlet air way down. Usually the open doors provide so much excess air that it cools the flue temps way down rather than raises them.
 
thekolmans said:
Hardrockmaple said:
Internal or external chimney? Do you have the manual for your stove, if not it is available online.

I do have the manual, and it's an internal chimney

First and foremost, check your local code.

If you have a taller than average straight run, it might work. I have 30+ ft of straight run 6 in. SS liner and I have a very strong draft.
 
I fired an 8" stove on a 6" chimney for yrs. If you have good draft it will work fine.
 
Battenkiller said:
barrettdp said:
I have a new Defiant install with 17' of 8" pipe and cannot realistically see running the stove with a screen and doors open, which was the only reason I went with 8" in the first place. The draft is to strong and would cause a very strong fire and over cooked flue pipe temps. The only way I could see to do it, at least with my setup, is build very small fires. I must admit however I am new to wood burning and this is my second stove. YMMV

Really? Not doubting you, but have you actually measured your pipe temps? I have a Vigilant with 25' of 8"x8" square tile chimney, and the draft is very powerful. I don't often burn with the doors open since the stove is in the basement and we don't hang out there, but I never get real high flue pipe temps with the doors open. Just the opposite, really. If I got a decent load going in the stove (1/3 full) with the doors open and then closed them, the flue temps would soar unless I shut the inlet air way down. Usually the open doors provide so much excess air that it cools the flue temps way down rather than raises them.


Like I said, I am a novice to this. I just ordered a flue pipe probe temp. However before I had double wall due to back orders, I had a section of single wall right above the adapter. It was very easy to get glowing red at start up with good dry wood with the doors open.

Even now with the double walled I can feel an immense amount of heat radiating from the outer wall, lots of paint discoloration, and lots of metal expansion pinging at start up with the doors open long before the stove top temp gauge gets up to even 300.

Kind of scaring my wife really. I couldn't imagine running a mid to large size load of wood with the doors open the whole time!
 
wkpoor said:
I fired an 8" stove on a 6" chimney for yrs. If you have good draft it will work fine.

Yep, Battenkiller makes a valid point, and both the stove damper and chimney restrict flow, so it will depend on what stove, draft, etc.

As a data point, the BK Princess and King have similar maximum burns, but BK specs a 6" pipe on the Princess, and 8" on the King, which has a bigger firebox to hold more smokey wood, and a bigger door to let the smoke out.

I was going to ask if anyone knew of an 8" stove stove that wouldn't reach maximum burn on a 6" pipe, but realized that's a stupid/useless question, since folks often report not being able to burn their 6" stove on a 6" pipe (draft, wood, etc.). :)
 
wkpoor said:
I fired an 8" stove on a 6" chimney for yrs. If you have good draft it will work fine.

EPA stove?
 
BeGreen said:
wkpoor said:
I fired an 8" stove on a 6" chimney for yrs. If you have good draft it will work fine.

EPA stove?
No, pre EPA stove. But I suspect it would have worked just as well for me. The stove I was using would get plenty hot on just a small amount of air like one turn out of the wheel. I have a 35' chimney + 6' of stove pipe. My current EPA stove 6" will run away on temps if I put anymore than 4 splits in it. In fact today I had a runaway and had to jam the pop can in the secondaires to slow it down.
 
Sounds like an atypical setup then. I agree that when you are above 30Ft of flue pipe that you may be able to reduce a size and still function well. But for the more average flue, this could be a bust.
 
What would EPA have to do with it anyway. With my very limited experience EPA stoves need less draft than the old ones. My EPA stove provides a much hotter flue temp than did my Pre EPA stove ever could have.
 
My experience is the opposite. EPA stoves often need a bit more draft. This is because of the longer path to feed air to the air wash and secondary combustion manifold. Frequently EPA stoves will run with cooler flues due to their more complete combustion.

A 35ft flue is beyond what the stove was probably tested or designed for. With a very tall stack and hot temps inside, it's possible that heat is being wasted by pulling secondary combustion up into the flue. If so, reducing draft and air intake should reduce flue temps while increasing the stove top temps. The old stove was working with a lower flue temp because it was effectively being dampered down from 8 to 6". The Magnolia is not being dampered down, but by the description, it sounds like it might need to be.
 
Old stove always ran a 2-1 or sometimes 3-1 flue temp. Sold to a friend who has it on a 7" chimney and he reports exact same thing. He called me after he had it in operation and said "whats up with the cld chimney thing". I wouldn't think 8-7 would be enough cause a problem, but hey haven't seen it operate on an 8" yet.
 
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