Flue Damper Too Small for Wood Stove 6" Liner

[gtandy6]

New to forum. I'm trying to install a wood stove insert requiring 6" liner. Liner fits easily in to chimney flue, until it reaches damper. Damper is too narrow to fit 6" liner; 5.5" in widest spot and ~4" in middle of damper due to protruding damper frame piece. See pictures. Any thoughts on transition pieces or ideas on how to get 6" liner to run thru middle of damper frame to top of wood stove insert ?

 

[begreen]

Take a grinder and/or sawzall and cut an 8-9" wide notch in the center. Then clean the chimney and smoke shelf very well.

 

[EbS-P]

I took out the entire damper and frame. 8 minutes with a framing hammer and pry bar. It was very easy to clean as I could stand up inside and get it all cleaned well.

 

[bholler]

I took out the entire damper and frame. 8 minutes with a framing hammer and pry bar. It was very easy to clean as I could stand up inside and get it all cleaned well.

Most are not that easy to remove honestly

 

[gtandy6]

Thanks everyone for the prompt response. Overall, I prefer to keep the damper in place to keep fireplace in tact in case I decide to remove wood stove in future. The damper frame does appear to be locked in and not easy to remove, so sounds like I need to use the grinder/sawzall to cut out the frame enough in the middle to allow for 6" liner. I was hoping this was a 'standard' problem and someone already invented an ovalized transition piece, but I guess I just need to roll up my sleeves and do some cutting. Thanks again.

 

[gtandy6]

Another thought. Just read my wood stove manual and it states that I can ovalize my liner, so I may consider an ovalized liner similar to one below at ChimneyLinerKit.com. Just need to verify my flue dimensions to fit ovalized liner. Looks like ovalized liner would fit thru my damper frame without any major cutting. Let me know if there is any potential downside to using ovalized liner.

6" Oval Double Ply Smooth Chimney Liner Kit

6" Oval chimney liner kit made of 316Ti stainless steel. The chimney liner kit is air and water tight, with 7 ply seams and is rated #1 in the industry for strength. UL Listed and made of the highest quality, hand picked, 316Ti 0.006 inches think stainless steel made in the United States and...

www.chimneylinerkit.com

 

[EbS-P]

What size is the current flue and are you insulating the liner?

 

[bholler]

Another thought. Just read my wood stove manual and it states that I can ovalize my liner, so I may consider an ovalized liner similar to one below at ChimneyLinerKit.com. Just need to verify my flue dimensions to fit ovalized liner. Looks like ovalized liner would fit thru my damper frame without any major cutting. Let me know if there is any potential downside to using ovalized liner.

6" Oval Double Ply Smooth Chimney Liner Kit

6" Oval chimney liner kit made of 316Ti stainless steel. The chimney liner kit is air and water tight, with 7 ply seams and is rated #1 in the industry for strength. UL Listed and made of the highest quality, hand picked, 316Ti 0.006 inches think stainless steel made in the United States and...

www.chimneylinerkit.com

You can ovalized but you shouldn't it is a standard issue and the right way to do it is cut the damper out

 

[begreen]

Thanks everyone for the prompt response. Overall, I prefer to keep the damper in place to keep fireplace in tact in case I decide to remove wood stove in future. The damper frame does appear to be locked in and not easy to remove, so sounds like I need to use the grinder/sawzall to cut out the frame enough in the middle to allow for 6" liner. I was hoping this was a 'standard' problem and someone already invented an ovalized transition piece, but I guess I just need to roll up my sleeves and do some cutting. Thanks again.

Save the cut-out piece. It can be welded back in if desired.

 

[bholler]

Save the cut-out piece. It can be welded back in if desired.

Or just bolted back in with mending plates

 

[Sodbuster]

Overall, I prefer to keep the damper in place to keep fireplace in tact in case I decide to remove wood stove in future.

That is blasphemy. 🤣

 

[EbS-P]

I won’t ever go back to an open fireplace. If the next owner wants one it’s on them to fix and the jotul is moving with me I mean I guess it has a price I’d part with it at.

 

[gtandy6]

What size is the current flue and are you insulating the liner?

Sorry for delay in response. I had to find time on my son's calendar for him to climb on roof and get measurements. The current flue opening is 11" X 11". Length from top of flue to top of stove is 27 feet. I have not yet selected liner; should I choose an insulated liner over a non-insulated liner. Based on forum feedback, looks like I will go with a round liner and not oval. Let me know if you have other thoughts. Thanks again. Much appreciated.

 

[gtandy6]

I won’t ever go back to an open fireplace. If the next owner wants one it’s on them to fix and the jotul is moving with me I mean I guess it has a price I’d part with it at.

Good advice

 

[stoveliker]

Insulated liner; the tall chimney will have cooler gases at the top. Best to keep them warm enough, so insulated liner.

May also be necessary per code (if you don't have clearance to combustibles from the outside of the brick).

And if it's 27' straight up (no elbows), a key damper, if at all possible. Draft will be high ...

 

[EbS-P]

What model of insert do you have?

 

[Jsd245]

I had the same issue with my stove. I have a large Rumsfeld style fireplace with a narrow damper. My installer upsized the liner to 8”and ovalized It to get it through the damper. The liner is insulated. Been installed that way for about 7 years now and no issues.

 

[brenndatomu]

Cut the damper out...if someone later wants to go back to an open fireplace (why?!) then a top damper can be retrofitted easily enough.

 

[gtandy6]

What model of insert do you have?

Quadra Fire 5100

 

[gtandy6]

Insulated liner; the tall chimney will have cooler gases at the top. Best to keep them warm enough, so insulated liner.

May also be necessary per code (if you don't have clearance to combustibles from the outside of the brick).

And if it's 27' straight up (no elbows), a key damper, if at all possible. Draft will be high ...

Thanks. Great advice. Can I ask what a 'key damper' is ?

 

[gtandy6]

I had the same issue with my stove. I have a large Rumsfeld style fireplace with a narrow damper. My installer upsized the liner to 8”and ovalized It to get it through the damper. The liner is insulated. Been installed that way for about 7 years now and no issues.

Thanks. Can you let me know if your installer used an oval liner or did he just ovalize the 8" round liner to fit thru the damper ?

 

[EbS-P]

Thanks. Great advice. Can I ask what a 'key damper' is ?

6-in Black Steel Stove Pipe Stove Damper https://www.lowes.com/pd/IMPERIAL-6-in-Black-Steel-Stove-Pipe-Stove-Damper/50019342

Thanks. Can you let me know if your installer used an oval liner or did he just ovalize the 8" round liner to fit thru the damper ?

This is not the best/recommended way. SawsAll with a metal blade or angle grinder. Yes you can squash it through but then you need to go 6”-8” oval then 8”back to 6”.

 

[mattie5960]

I had the same issue. We removed the damper and cut a hole in the damper framing large enough for the flue. Packed the open space with fiberglass insulation.

 

[EbS-P]

I had the same issue. We removed the damper and cut a hole in the damper framing large enough for the flue. Packed the open space with fiberglass insulation.

Fiberglass is not allowed. You need to use a mineral wool or ceramic insulation.

 

[stoveliker]

Key damper: basically a metal plate you can rotate to block flow or let it go parallel to the plate. It allows you to decrease the draft sucking on the stove flue collar.

They are cheap, as you can see in Ebs-P's link.