Chimney cap-- reducing the draft.

I think what you really need is a stovepipe damper.
Besides, there may be some days where you want
all of your potential draft.

There's lots of people who would like to be in your shoes......

Sounds like mainstation might be burning an insert, as the term "flex liner" is in the post. If that's the case, there's no way to install a stovepipe damper, because...there's no stovepipe. We could use some additional info about the installation. Rick

They might have been referring to a cap like a Vacu-Stack, specifically designed to address certain types of draft problems, but this is probably not what you need, as it is designed to ensure that wind increases the draft, not reduces it.

As long as everything seals well and the air inlet shuts down far enough, I would think you'd be ok. Might be better to try it with the insert before you start looking into modifications you might not need.

Nice signature, by the way!

The only reason why I mention the damper option is
because we have also have a flex liner, but it tees out
to a stovepipe & woodstove on the bottom. And yes, we
do have a stovepipe damper on our flue. Makes a world
of difference in the right circumstances.

mainstation said:

Yes insert, sorry. I will be replacing an old Regency which could runaway from time to time, mostly due to poor door seal and slight warpage. .

Click to expand...

Why not remedy this instead MStay?

Rob From Wisconsin said:

The only reason why I mention the damper option is
because we have also have a flex liner, but it tees out
to a stovepipe & woodstove on the bottom. And yes, we
do have a stovepipe damper on our flue. Makes a world
of difference in the right circumstances.

Click to expand...

Understood, Rob. Makes sense. Glad that works for you in your installation. Did you put the damper in originally, or retrofit it after learning how the system burns? Rick

fossil said:

Rob From Wisconsin said:

The only reason why I mention the damper option is
because we have also have a flex liner, but it tees out
to a stovepipe & woodstove on the bottom. And yes, we
do have a stovepipe damper on our flue. Makes a world
of difference in the right circumstances.

Click to expand...

Understood, Rob. Makes sense. Glad that works for you in your installation. Did you put the damper in originally, or retrofit it after learning how the system burns? Rick

Click to expand...

There are days when our flue drafts like a bandit, and it is nice to regulate it some.
Also, when it drafts well, we get great burns and longer burn times when we
"double damper" our woodstove (turn air control down & damper).