Maximum Flue Length (L); Additional Flue Parts; Standard 100 Mm Flue Systems - Worcester GB162-65 Installation And Servicing Instruction

INSTALLATION
8.3.3

MAXIMUM FLUE LENGTH (L)

The maximum pipe length (L) of the air supply and flue
gas exhaust pipes for the condensing gas system boilers
is determined by the total pressure loss of all
components in the flue system.
Maximum length of horizontal or vertical extensions for
100/150 flue system ( fig. 30 and fig. 31). For flue
length see table 6.
L
Fig. 30 Vertical flue length
B
A
Fig. 31 Horizontal flue length
A Distance from centre of flue to inside rear wall
B Distance from centre wall bracket to centre of flue elbow
L Distance from centre of flue to outside wall
Take the flue pipe clearances into account when
planning the layout of the place of installation
( subsection 8.3.1: "Siting the flue terminal" on
page 26).
Maximum wall thickness without extensions is 415 mm.
Maintain a minimum side clearance of 8 mm (
28
6 720 648 726-030.1TD
L
6 720 648 726-031.1TD
fig. 28).
8.3.4

ADDITIONAL FLUE PARTS

The additional flue parts listed can be ordered from your
supplier.
FLUE SIZE 100/150 AND 80/125
GB162 Maximum flue length [m]
concentric flue system
100/150
65 20
80 18
100 18
Table 6 Max. flue lengths, incl. wall/roofterminal in
meters
GB162 Reduced flue length [m]
concentric flue
system 100/150
bend extension
45° 90° 0.5m 1m
65 1.2 2.1 0.5
80 1.2 2.1 0.5
100 1.2 2.1 0.5
Table 7 Reduced flue lengths in meters
1) For every bend or extension the max. flue length (L) has to
be reduced
The total reduction length must never
exceed the maximum flue length.
WEATHERING SLATES FOR 100/150 AND 80/125
Flat roof, pitched roof.
8.3.5

STANDARD 100 MM FLUE SYSTEMS

The standard concentric flue system provides for a max.
horizontal straight length (
Full instructions for fitting this flue are in
subsection 8.3.6: "Installation of the horizontal flue" on
page 29.
IMPORTANT: Any horizontal flue system
fitted to a condensing boiler must be
inclined towards the appliance at an angle
of 52 mm per metre length to prevent
condensate dripping from the flue terminal.
This means that the clearance above the
appliance must be increased to match the
duct length. See fig. 6 on page 17.
6 720 648 726 (2011/07)
80/125
7.7
–
–
1)
concentric flue
system 80/125
bend extension
45° 90° 0.5m 1m
1.0 0.9 1.9 0.5 1.0
1.0 0.9 1.9 0.5 1.0
1.0 0.9 1.9 0.5 1.0
table 6, subsection 8.3.4).