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INSTALLATION & SERVICING INSTRUCTIONS FOR WORCESTER BOSCH
8-716-109-711a (04.05)
Flue terminals must be positioned to avoid
combustion products entering into buildings
The flue must be fitted and terminated in
accordance with the recommendations of
BS5410
The flue must not cause an obstruction.
Discharge from the flue outlet must not be a
nuisance.
Flue gases have a tendency to plume and in
certain weather conditions a white plume of
condensation will be discharged from the flue
outlet which could be regarded as a nuisance,
for example, near security lighting.
There should be no restriction preventing the
clearance of combustion products from the
terminal.
The air inlet/outlet duct and the terminal of the
boiler must not be closer than 25mm to any
combustible material. Detailed recommendations
on protection of combustible materials are given
in BS 5410:1
A protective terminal guard must be fitted if the
terminal is 2m or less above a surface where
people have access
The guard must be spaced equally (minimum
50mm) around the flue and fixed to the wall with
plated screws.
See 'Contact Information' on the inside front cover
for flue guard information.
The following additional guidelines (from part L
Exceptions Guidance Document) are
recommended when determining the flue outlet
position:
Avoid discharging flue gases into car ports or
narrow passageways
Minimum distance of the flue terminal to a facing
wall, fence, building or property boundary is
2500mm
Minimum distance of the flue terminal from above
ground is 2100mm where directed to a public
footpath, private access route or a frequently used
area and 2500mm from a car parking area.
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FLUE OUTLET POSITIONS
FLUE OUTLET POSITIONS
Minimum dimensions (mm) of flue terminal positions for oil-fired appliances:
TERMINAL POSITION
CF
RS(H) RS(V)
A Below an opening (1, 2)
N/A 600 N/A
B Horizontally to an opening (1, 2)
N/A 600 N/A
C Below a plastic/painted gutter, drainage pipe or eaves if combustible
material protected
N/A
75 N/A
D Below a balcony or a plastic/painted, gutter, drainage pipe or eaves without
protection to combustible material (3)
N/A 600 N/A
E From vertical sanitary pipework
N/A 300 N/A
F From an external or internal corner or from a surface or boundary alongside
the terminal
N/A 300 N/A
G Above ground or balcony level
N/A 300 N/A
H From a surface or boundary facing a terminal
N/A 600 N/A
J From a terminal facing the terminal
1200
K Vertically from a terminal on the same wall
N/A 1500 N/A
L Horizontally from a terminal on the same wall
750
M Above the highest point of an intersection with the roof
600
600
N From a vertical structure on the side of the terminal
750
750
O Above a vertical structure less than 750mm from the side of the terminal 600
600
P From a ridge terminal to a vertical structure on the roof
1500
N/A
Not applicable
N/A Not allowed
CF Conventional flue
RS(H) Room Sealed Horizontal flue
RS(V) Room Sealed Vertical flue
1 An opening means an openable element, such as an openable window, or a permanent
opening such as a permanently open air vent.
2Notwithstanding the dimensions above, a terminal should be at least 300mm from combustible
material, e.g. a window frame.
3 A way of providing protection of combustible material would be to fit a heat shield at least
750mm wide.
P
O
boundary
F
J
H
B
A
G
E
M
C, D
N
F
F
K
L
boundary
