5
FLUE DRAUGHT
The chimney can be checked, before the stove is installed, with a smoke pellet. If the chimney doesn’t
pull the smoke it may suggest the chimney needs attention (see the Flue Diagnosis Table, below).
Measurements
There is a flue draught testing point on the right hand upper side of the stove. (See fig. 3)
This test is only a guide as an apparently poor flue may improve once the stove is
installed, lit and the flue is warmed. If, once the stove is installed, there is any doubt
that the chimney is providing an adequate draught, a flue draught reading can be taken
with the stove lit. Two flue draught readings should be taken, one with the stove at
minimum firing rate and one at maximum firing rate. Close all doors & windows during
the test.
Minimum
The stove should be lit and allowed to warm the flue thoroughly. The air controls can then be set so that
the stove burns on a low setting. Allow the burning rate to become steady. The flue draught reading
should now be taken with the primary air intake closed and the airwash control fully open.
Maximum
The primary air intake can now be opened to allow the stove to burn at maximum rate. Give the stove
some time for the burning rate to become steady and then close the primary air intake, make sure the
airwash control is fully open and take a flue draught reading immediately.
Ideally, the flue draught reading should range between 0.05’ W.G (12.45 Pa) and 0.1’ W.G (24.9
Pa). Any readings significantly outside this range may indicate the need for remedial action.
Low flue draught symptoms: difficult to light and smoke coming into the room.
CAUSE
REMEDY
Cold chimney
Line the chimney
Chimney too short
Extend the chimney
Down draught
Relocate/extend chimney terminal. Fit an anti down draught cowl
Chimney diameter too large
Line the chimney
Chimney obstruction
Clear/sweep the chimney
Restricted air supply
Check for competing draughts (other chimneys, extractor hoods/fans).
Fit an air vent if the room Is sealed.
High flue draught symptoms: fire difficult to control, fuel will not last, stove too hot, stove damage, chimney
fire.
CAUSE
REMEDY
External wind conditions
combined with chimney terminal
Fit stabiliser cowl.
Fit flue draught stabiliser.