No Flue. If you have nothing
on your roof, you probably
have no chimney or flue and
will require a Power flue
that will fit on a suitable outside wall
Pre-Cast. Built into internal
wall from concrete breeze
blocks, identified by a ridge
vent or metal flue tube
and terminal.
Chimney (Class I).
A traditional brick or
stone-built stack with
accompanying terracotta
pot or gas terminal.
Pre-Fabricated (Class II).
Consisting of a metal flue
box and tubular flue system
protruding out of the roof
with a gas terminal or cowl on top.