3
even when the damper is in its “closed”
position. If local regulations permit, two
contained fireplaces can be connected
to the same chimney. However, you must
abide by local regulations regarding the
distance between the two connections.
Wood-burning stoves must never be
connected to chimneys that are also
linked to a gasfired heater.
An efficient
stove makes high demand on chimney
properties – so always have your local
chimney sweep evaluate your chimney.
Connection to a brick chimney
Brick a thimble into the chimney and
seat the flue gas pipe in this. The thim-
ble and flue gas pipe must not penetrate
the chimney opening itself, but must
be flush with the inside of the chimney
duct. Joins between brickwork, the thim-
ble and flue gas pipe must be sealed
with fireproof material and/or beading
Connection to a steel chimney
When fitting a connection from a top-
output stove directly to a steel chimney,
we recommend fitting the chimney tube
inside the flue gas spigot so that any
soot and condensation drops into the
stove itself rather than collecting on the
exterior surface of the stove. Changing
smoke outlet from top-mounted to rear-
mounted (see fig. 12-19 on page 12).
For connections to chimneys that are
run through ceilings, all national and
local regulations regarding distance to
flammable material must be followed.
It is important that the chimney is fitted
with roof support so that the top panel
of the stove is not required to bear the
entire weight of the chimney (excessive
weight may damage the stove).
Draft conditions
Poor draft may result in smoke being
emitted from the stove when the door is
opened. The minimum chimney draft to
ensure satisfactory combustion in stoves
of this kind is 12 PA. However, there
will still be a risk of smoke emission if
the firing door is opened during power-
ful firing. The flue gas temperature at
nominal output is 237°C when expelled
to an exterior temperature of 23°C. The
flue gas mass flow is 3.2 g/sec. The chim-
ney draft is generated by the difference
between the high temperature of the
chimney and the low temperature of the
fresh air. The length and insulation of
the chimney, wind and weather condi-
tions also have an effect on the ability
of the chimney to generate appropriate
under-pressure.
If the stove has not been used in a while,
check that the chimney and stove are
not blocked with soot, bird nests, etc.,
before using it.
Reduced draft can occur when:
- The difference in temperature is too
small – due to insufficient chimney
insulation, for example.
- The outdoor temperature is too high
– in summer, for example.
- No wind is blowing.
- The chimney is too low and sheltered.
- The chimney contains false air.
- The chimney and flue gas pipe are
blocked.
- The house is too airtight (i.e. when
there is an insufficient supply of
fresh air).
- Poor smoke extraction (poor draft
conditions) due to a cold chimney or
bad weather conditions can be com-
pensated for by increasing the airflow
into the stove.
Good draft occurs when:
- The difference in temperature between
the chimney and outdoor air is high.
- The weather is fine.
- The wind is blowing strongly.
- The chimney is of the correct height: at
least 4.00 m above the stove and free
of the roof ridge.
