3.8
FLUE SYSTEM
NB:
When installing a replacement boiler a new flue system must be used. Do
not re-use the existing boiler flue installation.
3.8.1
Design
Individual air supply and flue outlet
pipes are used. The material used for
flue outlet &/or air inlet must be
muPVC
to
BS
5255
and/or
BSEN1566-1 and BSEN1329 of an
internal diameter of 51 mm. (i.e.
nominal 50 mm diameter muPVC
solvent weld waste pipe). Marley
muPVC Solvent Weld Waste System
(50mm) and Polypipe System 2000
muPVC Solvent Weld Waste (50mm)
are recommended systems. DO NOT
USE ABS PIPE OR FITTINGS.
Alternatively, where flue or air intake lengths of up to 60m are require, Keston
Composite 75mm flue and air pipe can be used (contact your Keston stockist for
details). Keston Composite 75mm pipe MUST be painted where exposed to UV
light.
Both 50mm flue outlet terminal and 50mm air inlet terminal are supplied and are
illustrated in Figure 3.8.1. Both terminals are identical. If 75mm terminals are
required these can be obtained from your Keston Boilers stockist. Request part
numbers C.17.2.26.00.0 (terminals) and C.17.2.00.60.0 (50 to 75 adapters).
3.8.2
Maximum Lengths
The maximum lengths of
both air inlet pipe and flue
outlet pipe, when no bends
are used, are as detailed
below.
However, each bend used
has an equivalent length that
must be deducted from the
maximum
straight
length
stated above. Knuckle bends
must not be used.
A 92.5
o
sweep elbow is
equivalent to 1.0m straight
length. A 45
o
bend is
equivalent to 0.5m straight
length.
50mm
75mm
Maximum Air Inlet Length
:
39.0m
117.0m
Maximum Flue Outlet Length:
20.0m
60m
Maximum Total Flue and Air Intake Length :
40.0m
120.0m
WD500
Chapter 3 - Boiler Location
The Keston Q37 & Q37P Boilers
Installation & Servicing Instructions
Page : 18
Flue Outlet/Air Inlet Terminals
Figure 3.8.1 : Terminals
Figure 3.8.2 : Flue & Air Maximum Length Example
FLUE
c
d
AIR
a
b
KESTON Q37
