Conventional Flue Systems; External Vertical Conventional Flue (Green System) - Grant Vortex Series Installation And Servicing Instructions

Figure 9-2: Plume diverter kit - Plan View
Table 9-1: Distance of plume diverter centre from external wall
Model
21
26
36
9.3 CONVENTIONAL FLUE
SYSTEMS
! NOTE !
Under no circumstances can Grant Vortex boilers be
installed with existing flue systems. Only flue systems and
components suitable for wet flues should be used.
Failure to install the correct type of flue system will
invalidate the guarantee.
Grant condensing boilers have high operating efficiencies and
low flue gas temperatures. Care must be taken to ensure the
flue system is suitable for the very low flue gas temperatures and
condensate in the flue gases.
Suitable conventional flue systems are available from Grant UK.
The flue must terminate in a down draught free area, i.e. at least
600 mm above the point of exit through the roof or preferably
above the ridge level.
The condensate may be allowed to run back into the boiler. A
condensate drain at the base of the flue system is not required.
The high level flue terminal must be at least 600 mm from
any opening into the building, and 600 mm above any vertical
structure or wall less than a horizontal distance of 750 mm from
the terminal.
More detailed information on the siting of the flue terminal can be
found in Figure 9-5 and Table 9-3.
The internal flue diameter for all models must be 100 mm (4 in).
Twin wall flues are 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 Books 2 and 3)
for further guidance on conventional flue systems.
Page 28
Dimension A (mm)
251
251
224
! 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.
9.4 EXTERNAL VERTICAL
CONVENTIONAL FLUE (GREEN
SYSTEM)
The external system can terminate at either high level or vertically
(above roof level) as required. The vertical or high level terminal
must terminate in accordance with BS 5410-1. The minimum
dimensions for locating the high level terminal from building
features (windows, doors, etc.) are shown in Figure 9-5.
The Green system comprises of five insulated extension lengths,
45° elbows, a vertical terminal and a high level horizontal terminal.
Locking bands are provided with all vertical extensions and
terminals. Ensure that the locking bands are fitted.
Two types of wall bracket are also available (standard and
adjustable) to support the vertical flue components.
The maximum vertical height (from the top of the boiler to the
terminal) for the 'Green' system twin wall flue is 19 metres. Only
two 45° elbows may be used in the complete system.
If the flue terminal is fitted less than 2 metres above a surface to
which people have access, the terminal must be protected by a
guard. The guard must be manufactured from stainless steel and
should be fitted centrally over the flue terminal and securely fixed
to the wall.
CONNECTION OF GREEN FLUE SYSTEM
1. Connect Grant Green system to the boiler flue outlet using
the Grant Green system External Module starter elbow
(product code: GKM90 for models up to 26kW or GKM200 for
models ranging from 26-70kW).
2. Fit the starter elbow into the boiler connector after first
ensuring that the seal is in place in the connector.
! NOTE !
Lubricate the seal on the boiler connector using the
lubricant provided before attempting to fit the starter piece.
Ensure that seals in all flue sections are lubricated before
installing.
3. Assemble the remainder of the flue system as required,
lubricating the seal on each component before fitting and
securing every joint with the locking band provided.
The external vertical flue (Green system) components available
from Grant UK can be found in Figure 9-3 and Table 9-2.
Section 9: Flue System and Air Supply