Can I replace rigid flue with flex flue on DESA wood fireplace?

[OpenWoodFire]

So the question says it all but let me start from the beginning:

My wife and I purchased a house in summer 2011. It was built in 2005 and the fireplace was never used until we moved in. End of last cold season (Feb 2014) I had noticed some soot and creosote leaking out of the outer 12" flue onto the attic floor which told me the inner 8" is also leaking somewhere. We had a local hearth company check it out and do a sweep. They said the flue is no good/bad install, so we're looking to either rebuild or reline the flue. Here's the specs on everything:

DESA Model B36 open-front, smooth-face, wood-burning fireplace in corner install in living room (1-story)
The flue is a 12 3/8" outer with 8" stainless steel inner going up 8' into attic, offset, up another 7', then return and up through the roof with a round-top cap. Total pipe length is about 22'.

We had another chimney pro come out and we determined it was the angle that the flue had to been installed that caused the first elbow (offset) to come loose. Then, the weight of the off-set pipes had caused the sections to slightly come apart allowing the soot to be released.

I've found the original parts online but don't want the same result so I am looking at replacing the inner 8" flue with an 8" flex flue and still use the existing 12" outer pipe as insulation/protection. The manufacture (DESA) went bankrupt in 2008 and I believe assets purchased by FMI so it's hard to get their help and after searching online, I can't find any solution that involves flue repair with this unit. The other chimney ppl said they can replace it with flex using an adapter but I just can't find anything online that resembles doing that. Does anyone familiar with this have any take on it or recommend doing this with the unit I have? I've attached a few photos below for reference if it helps.

Thanks for any help in advance.

 

[bholler]

No you need to replace it with a chimney system approved for that fireplace unit. you can probably reuse allot of the parts but hard to tell without seeing it in person

 

[OpenWoodFire]

A lot of the parts are in perfect condition. It's mainly the first elbow and some of the angled sections. I just don't want to repeat what the original installers had done and not be able to run straight lines up. Would using flex be an absolute safety hazard, or not really possible, or just not recommended?

 

[bholler]

Well support it correctly this time and it wont be a problem. And yes just using flex would without a doubt burn your house down it is made to go inside a masonry chimney not be free floating in a flammable chase

 

[oconnor]

You need to differentiate between prefab chimney and chimney liner. What you describe in the photo is an 8" chimney with 2" of insulation. Some chimney systems can be relined to reduce the size, but if the fireplace requires 8" flue diameter, you won't fit 8" liner inside an 8" chimney, flex or not.

 

[bholler]

You need to differentiate between prefab chimney and chimney liner. What you describe in the photo is an 8" chimney with 2" of insulation. Some chimney systems can be relined to reduce the size, but if the fireplace requires 8" flue diameter, you won't fit 8" liner inside an 8" chimney, flex or not.

Yes and I am sure liners are not allowed according to the fireplace install instructions.