Section 9: Flue System and Air Supply
Page 31
! NOTE !
The Grant Orange system flexible stainless steel liner
is directional. The arrows marked on the liner MUST be
pointing vertically upwards, following the direction of the
flue gases. Failure to comply with this instruction could
lead to a leakage of condensate from the flue liner.
If a rigid flue is used externally, it must be of the twin-wall type,
to reduce the possibility of the condensate freezing in the flue,
incorporating seals at all joints, constructed with a stainless steel
inner skin and be suitably insulated and weatherproofed. The
internal flue diameter for a rigid flue for all Blue Flame models is
100 mm (4 in).
For a rigid conventional flue system Grant recommends the use
of the Grant ‘Hybrid’ flue system, which uses the Grant Green
and Orange flue system components for this application. Refer to
Section 1.3 for details.
! NOTE !
As no flue adaptor is supplied with the boiler, in order to
correctly connect the hybrid system, it will be necessary
to purchase the Grant CF adaptor kit (product code:
CFA15/70).
If required, it is possible to use the white painted single-wall
straight flue extensions, adjustable extensions and elbows from
the Grant ‘Orange’ system for the internal section of the flue
system, see Figure 9-3. These components can be fitted between
the boiler connector and flue adaptor. The flue adaptor, to which
the external twin-wall ‘Green’ flue components are connected, can
therefore be situated just before the flue system passes through
the wall. See Figure 9-4.
! NOTE !
Grant ‘Orange’ system single-wall flue components must
not be used externally.
The maximum vertical height (from the top of the boiler to the
terminal) for the 100 mm diameter hybrid ‘Green/Orange’ system
is 19 metres.
Grant ‘Green’ twin-wall flue is recommended for externally run
flues to reduce the possibility of the condensate freezing in the
flue.
No part of any flue system should be made of an asbestos
material; aluminium must not be used in any part of the flue.
Only stainless steel flue components should be used.
If the draught conditions are satisfactory, the flue should terminate
with a standard cowl.
Refer to the locally applicable Building Regulations, BS 5410:1
and OFTEC Installation Requirements (OFTEC Technical Books 2
and 4) for further guidance on conventional flue systems.
! CAUTION !
It is important to ensure that the flue system is sealed and
that condensate cannot escape. Up to 1.5 l/h of condensate
can be produced in a conventional flue system.
Do not use fire cement. The use of high temperature
silicone sealants is recommended.
! NOTE !
To comply with the requirements of the Building
Regulations Approved Document J - conventional flue
systems must have a flue data plate. A suitable data plate
is supplied with the Grant Orange flue system and should
be displayed next to the boiler or flue.
FLUE LINING KITS
Grant EZ-Fit Flexi Pack conventional flue system (Orange
System)
A range of Flexi pack conventional flue lining kits are available
from Grant UK. The packs have been specifically produced for
Grant Vortex oil fired condensing boilers.
The pack includes a terminal/top plate/flexi flue adaptor, stainless
steel smooth bore flexible flue liner, a rigid to flexi adaptor and a
boiler flue connector.
100mm Flue Lining components are suitable for use on all Grant
VortexBlue Internal models.
Table 9-2:
Conventional flue kits
Product code
Flexi pack (Orange system)
GFKIT 6/100
100 mm diameter x 6 metre
GFKIT 8/100
100mm diameter x 8 metre
GFKIT 10/100
100mm diameter x 10 metre
GFKIT 11/100
100mm diameter x 11 metre
GFKIT 12/100
100mm diameter x 12 metre
GFKIT 14/100
100mm diameter x 14 metre
GFKIT 16/100
100mm diameter x 16 metre
Extensions
A range of white powder coated single wall extensions are
available to connect the boiler to the flexible liner.
The nominal diameter of the extensions is 100 mm.
Extensions are supplied with locking bands.
Table 9-3:
Extensions
Product code
Extensions (Orange system)
WX 150/100
100 mm diameter x 150 mm
WX 250/100
100 mm diameter x 250 mm
WX 450/100
100 mm diameter x 450 mm
WX 950/100
100 mm diameter x 950 mm
WXA 250/100
100 mm diameter adjustable
extension (235 to 300 mm)
WE 45/100
100 mm diameter 45° elbow
! NOTE !
The rigid flue between the boiler and flexible flue liner
should incorporate an adjustable section to allow
inspection and cleaning of the flue system.
