In article ,
"IMM" writes:

"fred" wrote in message ...
They want the intake and exhaust flues to be balanced, that means
running two 50mm uPVC pipes to your chosen exit point.
Inlet & exhaust need to be separated by 200mm.

Are you sure? The advantage of twin flues is that the exhaust and air feed
can be in very different locations. The two pipes don't have to be near
each other or the sae length. For e.g, the exhaust run up to a ridge tile
and the air intake under the floor and penetrating the walls at low level.

The instructions for my Celcius 25 say a 'minimum' of 200mm, and
explicitly state no maximum distance. I also recall something about
not being permitted on opposite sides of a building but I can't find
that now -- it might have been in the instructions of a different
boiler I was considering at the time.

--
Andrew Gabriel