Wood stove in front of zero clearance prefab

[Magoo0512]

I have a zero clearance prefab fireplace in my house currently. It has UL listing warnock hershey tag on it. It would be about useless except for the fact that has a blower to move some of the heat from the top of the firebox into the room. I came across an F3CB in good condition for very cheap. Basically just trying to heat the main floor close to a 1000 sq. Ft. open floor plan. Will mainly just burn afternoons and evenings and weekends in an attempt to supplement some of the electric furnace bill. The fireplace has an 8-inch chimney in a chase that is 25 foot straight up and is interior and centered to the open floor plan. House is 25 years old 2 x 6 Construction and insulation I would consider as good not great but good. What I would like to do is put the stove on the hearth in front of the fireplace with a double wall tee connector off the back into the fireplace and then from there run a 6 inch stainless steel insulated flex pipe up through the 8-inch chimney to the top. I do understand that I will have to extend the hearth to get the proper ember protection out front of the wood stove
1) does this plan sound reasonable anything I'm missing or should look out for
2) can I back the woodstove up almost right to the Firebox of the Zc. I see the clearance is listed in the manual but those are for combustibles
3) should I make a heat shield for the top of the zc fireplace before where it meets the drywall when the stove is out in front

Thanks for any advice in advance! Stumbled on this website a month or two ago and have learned so much already

 

[bholler]

Not a bad plan just make sure you have the fireplace and chimney inspected fully to confirm it is in good condition and was installed properly. We see quite a few that where never installed correctly from the start and that could be dangerous.

 

[Magoo0512]

Will do had sweep out last year when we bought the house and said all looked good visualy and cleaned chimney. Do you think with an interior chimney of 25 ft straight I should install a key damper.

 

[begreen]

If it's not too inconvenient I would add a key damper. Worst case scenario, you decide to leave it open most of the time. We had that stove on a 12 ft, straight up chimney and it drafted fine.

 

[Magoo0512]

Okay maybe I could add one right at the back of the stove before it ties into the tee thanks! Any particular brand or a type that I should use or will any one work?

 

[begreen]

Griswald is a common brand.

 

[Dakotas Dad]

That's an interesting installation..

 

[kennyp2339]

I thought insulated flex chimney pipe is not rated to go in another metal chimney pipe, its only tested as a liner in an existing masonry chimney. I could be wrong though

 

[Magoo0512]

You may be right on the actual testing of it but dropping a UL listed insulated liner down a UL listed chimney that has had many fires in the past seems as though it would be safe no?

 

[kennyp2339]

You may be right on the actual testing of it but dropping a UL listed insulated liner down a UL listed chimney that has had many fires in the past seems as though it would be safe no?

Some of the liners that are used for zero clearance applications are not class a compliant and only rated up to 1,100 deg's. That's why I chimed in, you may want to make sure your existing chimney pipe is class a pipe before ordering your chimney liner.

 

[Magoo0512]

My existing chimney pipe in my zero clearance prefab is UL 127 rated to 1700 degrees. But by putting in 6 inch stainless steel insulated liner down it am i not upgrading it to UL 103HT. Thanks

 

[begreen]

Some of the liners that are used for zero clearance applications are not class a compliant and only rated up to 1,100 deg's. That's why I chimed in, you may want to make sure your existing chimney pipe is class a pipe before ordering your chimney liner.

Many older ZC fireplaces have air cooled chimneys. It's my understanding that if an insulated liner is dropped down the ZC chimney it doesn't need to be class A chimney. See condition #4 here:
(broken link removed)

 

[Magoo0512]

Thanks for the link the wood hearth stove reline is exactly what I'm attempting to do.