godin stove chimney problems

[malcolmpa]

We had a Petit Godin stove installed in our kitchen by a local supplier.Sadly we,ve had problems.
The 125mm.flue pipe goes directly from the rear of the stove thru the wall(horizontally for almost 1 m.) into an attached barn ,then up the wall to the roof .The supplier said single skin stainless steel would be fine ,since it was not "really" outside.
After initial condensation problems the outside chimney was "lagged" and this seemed to be ok until for some reason the 'T' deformed and the chimney slipped down.The result was that some of the nearby timbers set on fire!!
After the replacement of the 'T' and the chimney supports the same problem has occurred again.
The supplier is now suggesting that the horizontal section is the problem(despite having installed it).
Clearly I have "issues" with the supplier ,but has anyone had a similar problem and found a solution.

 

[RigidRaider]

I don't know much about this but from what you write the installer sounds like un vrai cowboy. Firstly in the UK (and I'm sure in France) there are stringent rules about this kind of flue, meaning that it must be double walled, insulated and no combustible material must come within a certain distance, 2 inches I think. Secondly a single skinned flue will not warm up adequately to allow the rising column of hot gases, which creates the vacuum and hence the draft, which you clearly need to overcome the long horizontal section. I bet it doesn't draw well when you light it? Thirdly I'm not sure what you mean by the T but if it's the junction where the vertical pipe joins the horizontal, it will not be strong enough to support the weight of the entire flue, which should have supporting brackets attaching it to the structure of the house.

Why the long horizontal section? Why couldn't this go up obliquely through the wall?

"Il faut tout refaire" is what you need to be telling him.