Flue Terminal Positions; Air Supply - Bosch Worcester 14/19CBI Installation And Servicing Instructions

5. Flue terminal positions

The flue system must be installed following the requirements of
BS5440:1.
The standard flue kit length is 425 - 725mm. Extension kits for
flues up to 3.0m are available.
A rear flue suitable for walls from 220 - 375mm thick is available
which can be contained within the boiler casing.
The terminal must not cause an obstruction nor the combustion
products a nuisance.
If the terminal is less than 2m above a surface to which people
have access then a guard must be fitted. The guard must be
evenly spaced about the terminal and fixed with plated screws.
A guard Type K2 can be obtained from Tower Flue Components,
Vale Rise, Tonbridge, TN9 1TB.
It is essential that products of combustion cannot re-enter the
building. Refer to Fig 4.
Fig. 4. Siting of the flue terminal.
*NOTE: A minimum of 75mm must be achieved
where the terminal is near fusible or combustible
material such as plastic drain pipes, guttering or a
carport roof UNLESS suitable heat shields are
provided.
A
D
TERMINAL POSITION
A– directly below an openable window or
other opening e.g. air brick.
B– Below gutters, soil pipes or drain pipes.*
C– Below eaves.*
D– Below balconies or car port roof.*
E– From vertical drain pipes and soil pipes.*
F– From internal or external corners.
G– Above ground, roof or balcony level.
H– From a surface facing a terminal.
G
B,C
HI
F J E
MIN. DISTANCE
A separate vent for combustion air is not required.
The appliance can be fitted in a cupboard or compartment with
no vents for cooling, but the minimum clearances must be
increased to those given below. Refer to BS6798.
Note: the clearance at the front is to a removable panel, e.g. door.
The user must be informed not to restrict the clearances by the
addition of extra shelves etc and that flammable materials must
not be stored in this compartment.
Above Appliance (when using Rear only Flue)
Above Appliance (when using
In front
Below
Right-hand side
Left-hand side
If the appliance is fitted in a cupboard or compartment with less
clearance than those stated in the table above (minimum
clearances are given in Section 4 Siting the Appliance) then
permanent air vents for cooling are required, one at high level
and one at low level. Both high and low level vents must
communicate with the same room or must be on the same wall
to outside air. The minimum requirements are:
Model Position of vent
19/24CBi
14/19CBi
9/14CBi
If the boiler is fitted between kitchen units and a decorative
door panel is fitted then the top and bottom of the space must
be left open.
F
F
A
G
M
TERMINAL POSITION
I– From a terminal facing a terminal
300mm J– From an opening in a car port (e.g. door
75mm window) into dwelling.
25mm K– Vertically from a terminal on the same
25mm wall.
25mm L– Horizontally from a terminal on the same
25mm wall.
300mm M– From door, window or air vent.
600mm
7

6. Air Supply

horizontal flue) 180mm
Air from room
2
High 255cm
2
Low 255cm
High 207cm 2
2
Low 207cm
High 152cm 2
Low 152cm 2
L
K
L
K
MIN. DISTANCE
1200mm
1200mm
1500mm
300mm
300mm
30mm
340mm
200mm
105mm
105mm
Air from outside
2
128cm
2
128cm
104cm 2
2
104cm
76cm 2
76cm 2