andrews HIflo EVO HF 30/300 Installation And Service Manual page 11

Figure 4
Heater with
highest usage
fitted nearest to
main flue
(if applicable)
Minimum Heights from Roof to Base of Flue Terminal
Type of Roof
Pitched
Flat
Issue 4 21042918
Each unit has an
atmospheric burner
system & uses natural
gas.
structure = on the roof
Internal Route
On Ridge
Pitch
exceeding
At or
45°
above
ridge
Pitch not
level
exceeding
45°
With
parapet
Not
applicable
Without
parapet
Figure 4
Common flues may be used on multiple installations
only if all the heaters are of the same burner system
and fuel type and should be sized to ensure complete
evacuation of the flue products from the installation.
Where one flue is to be used more regularly or for
longer periods than the others in the group, it should
be connected at the point nearest to the main flue
See BS 6644 Clause 20 for further
information and recommendations on this
as well as general flue requirements.
Fit a flue clip or flange joint close to the diverter
so that it is secure but can be disconnected for
servicing. The weight of the flue must be borne
by securing clips, etc. and not by the heater
Not within 1.5m of a
vertical surface of a
External
Route
Not on Ridge
1m 1m
above roof above roof
intersection intersection
600mm
The base of
above roof
the terminal
intersection
should be
600mm
600mm
above roof
above the
intersection
level of the
250mm
adjacent
above roof
roof edge
intersection
Within 1.5m of a
vertical surface of a
structure = on the roof
Internal External
Route
Route
The base of the
terminal should
be 600mm
above the level of
the adjacent roof
edge
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