Any issues or concerns going from 6" stove outlet to an 8" chimney

[BobUrban]

I had an 8" class A chimney installed this year to run my VC Defiant that was given to me but plan to upgrade to a modern EPA stove next year. My reason is all of the above regarding cleaner, safer and possibly longer burns while lowering wood comsumption.

Is there anythnig I need to worry about when I change the stove to one with a 6" outlet. Seems all the modern stove are 6 and my chimney is 8"

Just doing my homework on what stove I want by searching here and asking questions.

Thanks

 

[SolarAndWood]

I had 8" because of a VC too and glad I did because it was dumb luck. There are at least a couple nice options you might want to consider that a lot of people can't because of the 8" requirement: Hearthstone Equinox and Blaze King King.

 

[Agent]

Yup, I'm also running a 6" stove to an 8" pipe. Works like a champ. Plus it's within the 2.25x cross sectional area requirement. And you have ton's of options in the future as Solarandwood said.

 

[BobUrban]

Thanks guys. This place is great. So much information to absorb. I figure taking a year to decide and making my purchase in the off-season will give me the most bang for the buck.

All of you who have gone from a 8-6" stove keep your findings coming

 

[mepellet]

I am hoping to upgrade my wood stove next year and also have an 8" chimney. What is the harm in using a 6" stove with an 8" chimney? Does it void any warranty or do insurance companies not like it?

 

[BobUrban]

I don't think there are any insurance issues - especially if you are going to an EPA UL rates stove. I was more concerned with draw and heat loss issues?? Looks like I have more options than I realized.

 

[SolarAndWood]

Looks like I have more options than I realized.

Yep, the Equinox is one of the most beautiful stoves out there and the Blaze King King is arguably the best utility heater. Pretty sure there are a few other 8" stoves out there worth considering as I recall.

 

[BobUrban]

WOW - the equinox is beautiful but at 5G it may not be my first choice. I don't need that much heat so one of the smaller soap stone models may fit my budget and house

 

[SolarAndWood]

lol, never said it was the cheapest

 

[greythorn3]

the older blaze king princess cat model i picked up has a 8" flue too. thats why i got it to replace my non epa blaze king king, and i didnt wanna change out the chimney

 

[Deuce95ci]

Switched out my monster Glacier Bay non-EPA stove w/ a Liberty. After a week everything seems to be working well. My setup is 6' of single wall to a 6" 90, 6"-8" reducer, 3' of double wall stainless laying horizontal into a Stainless clean out tee and 8' of double wall on top of tee. I'm 3' above my 10 foot circle, pipe exits on north side, I used to get a little smoke thru the seams of single wall with the old setup when we got very high north wind, but haven't had any high winds since I switched stoves.

 

[wmarazita]

Hi BobUrban,

I am about 6 months ahead of you, but had the exact same questions that you have. The folks here were able to answer all of my questions and concerns. This what I did:

I was replacing an old non-epa stove that had a decent 8" chimney and wanted options. I didn't want to have to replace the 8" chimney. I figured that a 6" stove would be out of the question. To my surprise, I found that some (if not most) of the 6" stoves will draft and operate fine with the 8" chimney. I decided on the Englander 30 which has a 6" flue. I now have 6" single wall stove pipe coming out of the Englander, then two 45 degree elbows, and then a 2 foot horizontal pipe that goes out through my 8"thimble through the wall into the 8" chimney. I packed "rock wool" around the 6" pipe inside of the thimble and then placed a trim collar over the pipe to cover the gap. The Englander manual confirmed that the 6" flue would have no problem exhausting into the 8" chimney. I am happy to report that it works like a champ and I have not had any drafting issues.

Bill

 

[BobUrban]

This is all good news for me. My set up is a straight shot through the house about 18' So I do not have to turn at all. I do have 8" double wall black stove pipe that has lifetime on it so I am hoping to use as much of that as possible. Is there any problem if I come out of the stove at 6" and directly into an 8" stove pipe within 2-3'. Obviously with an adapter so that all fits snug.

Thanks again everyone

Bob Urban

 

[wmarazita]

This is all good news for me. My set up is a straight shot through the house about 18' So I do not have to turn at all. I do have 8" double wall black stove pipe that has lifetime on it so I am hoping to use as much of that as possible. Is there any problem if I come out of the stove at 6" and directly into an 8" stove pipe within 2-3'. Obviously with an adapter so that all fits snug.

Thanks again everyone

Bob Urban

Hi Bob,

I am responding in order to bumb this back to the top, but hopefully someone with more knowledge than me will give you some additional guidance.

If I were you, I would suggest that you pick out a few stoves that you think would work for your space that you are trying to heat and then read through their installation manuals. You need to look and see if the manufacturer of the particular stove says it is OK to have the 6" flue exhaust into an 8" chimney. Like I said, the Englander manual stated that I could go up to a chimney that had a cross section of 2.5 times the flue size. Since the flue size on the Englander was 6", simple geometry (A=2 x pi x radius squared) tells you that a 6" flue has an area of 28 sq inches and that a 8" flue has an area of 50 sq inches. So, going from the 6" to the 8" diameter is less than the 2.5x, so I was good to go. So, it seems to me that you could do what you are suggesting, as long as your particular stove manufacturer says it is OK.

That being said, just because the manual says you can do it safely and that it will draft properly, your real world results may vary. This is where the experts on this forum should be able to help out and give you all the advice you need. Hopefully someone will respond with more help.

Bill

 

[Agent]

My Englander adapts from 6 to 8" within about a foot of exit from the stovetop. My adapter is connected directly to an 8" 90 elbow and still drafts pretty darn well.
Adapting within two to three feet will be nice when you go to clean the chimney, as you'll probably have to remove the adapter.

 

[Backwoods Savage]

Many folks who have a stove that recommends 6" and then that goes into an 8" chimney have drafting problems. The problem arises in that there is so much more volume in an 8" vs. a 6". Some say it works well but many have big problems. Just giving a "heads up." Best if changing stoves to get a stove that requires the 8".