# 8" flue in stove-reduce to 6" in chimney?



## Fred Wood (Sep 21, 2010)

I just got an older really heavy big woodstove. It was my dad's and he ran all 8" from the collar on the stove, straight up and outside........ It was always an awesome woodstove!

My question is this. Can I reduce the chimney size to 6" right off the stove with a reducer? If they had designed it for an 8" will 6" still work but just at a lower temp, or am I asking for trouble? I just spent over $1000 on my 6" chimney last year, not to mention I have a brand new woodstove I used for about two months----it's just too small and I cant fill it enough to burn over 3-4 hours.

thanks you for any input!!

FW


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## begreen (Sep 21, 2010)

That's too bad. Hope this is not an old smoke dragon replacement. It may work. Can you describe the 6" flue system in detail? Height, elbows, interior or exterior?

What is the stove make and model?


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## Fred Wood (Sep 21, 2010)

Hey! Thanks for the quick reply!! I have a pic of the interior in my album from last year that I'll dig out and add to this post. It was NOT a smoking dragon at all---the LOPI 380 I have is, haha. I am not even sure of the make and I will go out to my shop and see--I used to know it. It's really cool stove that my dad got at 'The Home Show' in Seattle way back and if I remember correctly it was made here in WA, actually in Roslyn----you may very well be familier with them........
I will go get a pic----well, it's wrapped up but I 'll get the name. 

I am down on The KP.....

FW


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## Fred Wood (Sep 21, 2010)

Here's the current set-up in our family room with the Century FW2700. The jog in the stack was necessary to avoid cutting a truss. But it's 6" single wall to the kit in the ceiling and then 5' above the roof in order to keep the cap 36" above nearest obstruction within 12'.

The stove were talking about is a Mountain Aire.......is the only info I could find without unwrapping the whole thing; and it says that on the frount of the little hearth that sticks out 6". I did a Google search and found nothing.....albeit I didn't look very long. I will now.


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## begreen (Sep 21, 2010)

I would find out a bit more about the stove first. It may have a lot greater clearances and hearth requirements, hard to tell without more info. 

The Century should be able to keep up with most PNW weather in an average sized house. Maybe not the coldest days, but most. How many square feet are you trying to heat?

One thing that will make a difference is if the wood was not fully seasoned, it's heat output could have been compromised. Modern EPA stove really burn best with wood that is below 20% moisture.


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## rhetoric (Sep 21, 2010)

When we moved into our home we had a older steel woodstove that had a reducer on top of the stove (8 inch stove -- 6 inch flue).  I suppose I can't be sure it was the fault of the reducer, but the stove did smoke quite a bit.


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## begreen (Sep 21, 2010)

Yes, it's a compromise at best. I would think of selling the Century + the Mountain Aire and putting those funds toward a new Englander 30NC or similar 3 cu ft stove. Take the tax credit and it should be a wash for costs, but you will have a stronger, cleaner heater.


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## sksmass (Sep 21, 2010)

So, I have a related question:  I thought, by code, that you could NEVER go smaller than the pipe that came off the UL appliance.  That is, if the stove had an 8" collar, then you had to go 8" round (or ovalized equivalent) all the way to daylight.  Is that not correct?


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## Highbeam (Sep 21, 2010)

It won't pass inspection but then again, the whole installation is illegal. Installing a pre-EPA stove is illegal in WA. What do you think your insurance company will say about a non-inspected illegal installation? What do you think they will say in the event that your house burns down? I'm with BG, dump both stoves and upsize to a NC30.


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## Hiram Maxim (Sep 21, 2010)

Highbeam said:
			
		

> It won't pass inspection but then again, the whole installation is illegal. Installing a pre-EPA stove is illegal in WA. What do you think your insurance company will say about a non-inspected illegal installation? What do you think they will say in the event that your house burns down? I'm with BG, dump both stoves and upsize to a NC30.


*+1*


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## Fred Wood (Sep 25, 2010)

Thanks very much for the feedback!!  

So I've been stove shopping all week and yeah, there's some really nice ones! We are going with the Lopi Liberty with the pewter door and legs---this is if he can have it by wednesday.....I only say this because he promises it by tuesday, lol. I figure I will sell the Century, keep the old Lopi around and use the stove my dad just gave me for trash outside instead of my burn barrel, haha, jk: just for you smoke dragon hounds and green wood burners alike. I am just an illegal kind of guy............. 

Peace!


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## Renovation (Nov 5, 2010)

Not that it is useful to the Original Poster, but I've been researching running a Blaze King King (8" outlet and chimney spec) with a 6" chimney, and thought I'd give back a little by sharing what I've learned.

Here's a PM conversation with a guy who was kind enough to share his experiences with that configuration.  I'll leave his name out, since I don't know if he'd like to be mentioned.



> Hey George,
> The dealer I bought my Blaze King King from shared that I could run 8” pipe from the stove up to a 6” increaser.Which means my 6” insulated pipe going through the ceiling is attached to a increaser which is 6” at the top end and 8” at the bottom end attached to the 8” pipe going into the stove.Now my hook up is single wall pipe.The manufactuer calls for double wall pipe.I get a little smoke spillage due to I think the single wall pipe and my pipe isn’t as high as I’d like.Your 25’ chimney should work very well.Go for it and keep us posted.
> 
> Now remember that you need 8” pipe coming off the stove not 6” pipe.I have about 5 feet of 8 ” running diagonally to the 6-8” increaser which is attached to 6 ” metalbestos pipe going through the ceiling and runs about 9 ft above the roof.I get about 15-17hrs of heat and I picked up my pipe from Lowes.Some say use 45’s however I used two 90’s.I think at some time I’ll go double wall using the 45’s.Go on and try my set up using the 8” double wall to increaser into your insulated pipe.Oh do you already have a 6” insulated chimney set up ? If not and your starting from scratch just go 8” for highest performance.



One interesting aspect is that the dealer recommended running 8" stovepipe all the way the chimney, and downsizing there, *not* not downsizing to 6" right at the flue.   I hope someone finds this helpful.


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