Wood Stove Insert Installation Validation

[jsjamboree]

Hoping to get some validation that my installation plan doesn't have any direct issues, or there are some suggestions I should take.

Removed a standard wood insert and am installing a wood stove insert, the previous insert utilized an 8" flexable flue through an exterior chimney and comes in at about a 45deg angle from the back. Picture Included (yes I know it needs cleaned bad, I haven't used it). I purchased a Century CW2900 wood insert that has a 6" flue outlet. Reading over the installation instructions it says you cant go lower than 6" but doesn't say you cant go above 6". Reading other threads on this site, it doesn't seem to be an issue going larger unless the manufacturer says specifically not to.

My plan is to use a 6" 90deg single wall flue pipe out of the stove, into a 6" to 8" 'reducer' and then utilize the existing 8" flue. Rivit those pieces together and seal with some high temp sealant. The 90deg will allow for 0-90' bend so it will allow for mating up the angle correctly. I plan to pack insulation just above the 8" flue joint to prevent cold air entering and will utilize some sort of block off plate below that (though with the setup it wont be air tight, likely will slip in after its all installed.

Suggestions or comments? Thanks

 

[bholler]

Hoping to get some validation that my installation plan doesn't have any direct issues, or there are some suggestions I should take.

Removed a standard wood insert and am installing a wood stove insert, the previous insert utilized an 8" flexable flue through an exterior chimney and comes in at about a 45deg angle from the back. Picture Included (yes I know it needs cleaned bad, I haven't used it). I purchased a Century CW2900 wood insert that has a 6" flue outlet. Reading over the installation instructions it says you cant go lower than 6" but doesn't say you cant go above 6". Reading other threads on this site, it doesn't seem to be an issue going larger unless the manufacturer says specifically not to.

My plan is to use a 6" 90deg single wall flue pipe out of the stove, into a 6" to 8" 'reducer' and then utilize the existing 8" flue. Rivit those pieces together and seal with some high temp sealant. The 90deg will allow for 0-90' bend so it will allow for mating up the angle correctly. I plan to pack insulation just above the 8" flue joint to prevent cold air entering and will utilize some sort of block off plate below that (though with the setup it wont be air tight, likely will slip in after its all installed.

Suggestions or comments? Thanks

Well first thing is first. Get that liner clean and have a camera run through it to check its condition. Then find out if its insulated or not. Then if all that checks out you could try it. It may work ok it may not how tall is the chimney?

 

[Rickb]

It also looks like there is fiberglass insulation in there..... I would remove all of it.

 

[bholler]

It also looks like there is fiberglass insulation in there..... I would remove all of it.

Yes the fiberglass needs to go

 

[jsjamboree]

Well first thing is first. Get that liner clean and have a camera run through it to check its condition. Then find out if its insulated or not. Then if all that checks out you could try it. It may work ok it may not how tall is the chimney?

The existing 8" flue pipe is insulated, its a two story house I would estimate about 25-30' chimney stack.

Yes the fiberglass needs to go

Yes for sure, I do want to put something else up around the flue, is there anything that is more pliable like fiberglass that I can use? Ive only seen the rockwool sheets but due to the way the chimney enters the house it would be really hard to get a tight seal around it with that.

 

[bholler]

The existing 8" flue pipe is insulated, its a two story house I would estimate about 25-30' chimney stack.



Yes for sure, I do want to put something else up around the flue, is there anything that is more pliable like fiberglass that I can use? Ive only seen the rockwool sheets but due to the way the chimney enters the house it would be really hard to get a tight seal around it with that.

With the height you have and the fact that it is insulated i would say it will probably work fine. And if it doesnt you can always just drop a 6" through that liner at a later point.

As far as sealing it stuff rock wool around it then make a sheet metal plate to stop airflow.

 

[yooper08]

Going bigger can be ok up to a certain point considering the system as a whole. As far as sealant goes, not sure if that's necessary. Could also produce a bad smell.

 

[begreen]

Going bigger can be ok up to a certain point considering the system as a whole. As far as sealant goes, not sure if that's necessary. Could also produce a bad smell.

Correct. Don't use sealant on hot flue pipe. Do use stainless steel fittings and make sure that there is room for the elbow and increaser.