Chimney and liner question

[CheaperthanYou]

Hello, i am planning my insert install. I am going to be putting a osburn 2200 in my 1947 Levitt ranch.
Currently we use our center of the house fireplace with a manifold i fabricated from 3" pipe and a blower to get heat from our fireplace.

When i install the insert i will be using a 6" stainless liner .

In the future i plan on renovating the upstairs of the house, and the room that the chimney is in would bennifit greatly if we removed the brickwork.

Currently there is a large 2 flue chimney, one for the firplace and one for the oil burner (the oil burner no longer uses this, as it was relocated some time ago.

Most other levitt owners have removed the upper portion of the chmney and did the necessary wood work to suport the roof and upstairs. so they have more living space, these people dont use the fireplace because there is now no flue.

I was wondering if there is a way that i can use my 6" chimney liner, all the way through and also shrink the footprint of the chimney that runs through that room? Can i use a zero clearance chimney in that room say 8" and run my 6" liner through it?

I know this may sound confusing im just trying to plan for the future here while getting my house ready for the insert.

thanks

what would be the to-code way of doing this

 

[clemsonfor]

If you have a second flue in that masonry chimney you can remove all the brickwork associated with the unused flue and then seal it up at floor level. in theory as long as you have a chimney chase thats approved i think you can run the liner through it. I think this would even include just a plain block chase with the liner in it?? I am not sure as codes and all go??

My farm house was just a single brick chimney about 21x18 and i have the liner running through it. A block chimney would actually have more protection than that as there double walled in theroy. Although my liner hovers in the middle of most of the brick chimney.

Just rambling here.