liner requirements for zero-clearance fireplace chimney

[letove]

Hello. I am new to this forum. I moved into a house two years ago with a Heat-N-Glo zero-clearance metal fireplace (piece of junk) with a 25' high double-wall metal vented chimney built inside a wood-framed chase. I wanted to install a woodburning insert, but realized my options are very limited in this application.

Instead of an insert, I'm going to put a free-standing Hearthstone Heritage with a rear heat shield and horizontal exit double-wall stove pipe. I am going to buy a custom hearth pad that is rated at least R 1.2, per Hearthstone manual.

The exisiting double-wall metal chimney is 8" inside diameter. I am going to have a 6" rigid stainless liner installed inside the 8" chimney, and run the horizontal stovepipe into a 6" tee which will end up inside the existing zero-clearance fireplace firebox.

I have a couple of estimates for installation of the liner and stove. Some installers want to fully insulate the liner, others say it's not necessary in my application (also much cheaper installation). I spoke with my local fire inspector, and he said use of insulation depends on the liner literature. Any advice on whether liner insulation is necessary or not?

Does anyone know if I can use the existing chimney cap, or do I have to replace the cap when the liner is installed?

Lastly, do I need to ensure that whatever top plate is installed with the liner, allows air to circulate through the outer chimney layer?

Any help or advice would be appreciated.

 

[cmonSTART]

Especially if you do not insulate you need to use a proper top termination to ensure the old chimney can circulate air. There are a couple on the market. And whether or not you need to insulate does depend on the liner used. I would replace the existing cap with the one the liner uses.

I think Homesaver liner has a special top termination for ZC fireplace chimneys.

ZC fireplaces are a pain in the rear.

 

[Dakotas Dad]

Bet you would be happier if you just tore out the ZC and chimney and started over.

 

[letove]

When I bought this house 2 years ago, I thought I could easily put a large wood-burning insert in the fireplace and I'd be good to go. Only when I started to research inserts did I learn there was such a thing as a pre-fabricated fireplace (and I had one), and the frustration set in.

Ideally I would rip the zc system out and go with a larger-capacity free-standing stove and new chimney, but budget constraints are holding me back.

Thanks for the feedback received so far. If anyone else has advice, I'd sure appreciate it.