Reducing overdraft on already installed insert

[batmanavich]

Hello Everyone, you were all a great help to me when I was planning the install and learning how to operate my Fireplace Insert last season.

My setup is a Kuma Sequoia with an 8" flexible liner going up approx. 26'. Chimney overall height slightly exceeds 30'.

When I was planning the install, someone wisely stated that it may be recommended to go with a 7" liner. I did contact Kuma at that time and consulted with them about the concern. The concern was validated, but I was also informed the stove was tested/listed with an 8" liner. I chose to install the 8" liner, to be consistent with the listing.

Last year I had a little bit of a learning curve operating a catalyst fireplace but I thought I had a good hang of it. Last night I noticed the catalyst is coming apart, and I will need a new one. The other problem is that when the stove is turned down all the way, there are still a LOT of flames present.

In hind sight, I have always been disappointed with more than likely short burn times, and a difficulty in being able to choke it down. I believe I may need to try to place a reducer at the top to slow down the airflow. Similar to these:

(broken link removed to http://www.lindemannchimneysupply.com/chimney-liners-pipes/liner-accessories/reducers/m-flex-304-reducer-increaser.html)

https://www.rockfordchimneysupply.com/free-flow-chimney-liner-increaser-reducer.php

https://www.rockfordchimneysupply.com/standard-reducer-increaser.php

Any idea if these would help my issue?

 

[bholler]

I would find the air inlet and restrict that. Many times simply reducing the size at the top does not do much. And even if you had put in a 7" you may still have a problem. 7" would reduce the volume a little but it would increase the velocity as well with that much height i think restricting the inlet is the best option. Hopefully some one who knows that stove better than me will come along to give you advice on doing that.

 

[Woody Stover]

Can you remove the surround and install a pipe damper? Then you could run a rod through a small hole in the surround to allow you to adjust it. Close it when it's cold outside and draft is strong, open it if needed when outside temps are moderate.

 

[bholler]

Can you remove the surround and install a pipe damper? Then you could run a rod through a small hole in the surround to allow you to adjust it. Close it when it's cold outside and draft is strong, open it if needed when outside temps are moderate.

That would be a great solution if possible but it rarely is with an insert

 

[Woody Stover]

That would be a great solution if possible but it rarely is with an insert

I didn't need it on the 20' stack, but on the Buck 91 it looked like maybe I could do it by drilling the shaft holes in the 15* elbow, just above the flue collar on top of the insert, but I'd have to determine if the plate would have enough room to open all the way. I guess it would depend on how his liner is connected to the Kuma. Pic would be nice...

 

[kuma.jason]

Be sure to call us if you need help sorting this out. We can help with the warranty on that Catalytic, and offer some ideas for taming the draft.

888-714-5294