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3.1 GAS SUPPLY
The Alpha CD12S boiler requires a gas rate of 1.3 m³/h (45.9 ft³/h).
The Alpha CD20S boiler requires a gas rate of 1.96 m³/h (69.2 ft³/h).
The Alpha CD28S boiler requires a gas rate of 3.04 m³/h (107.3 ft³/h).
The meter and supply pipes must be capable of delivering this quantity of gas in addition to the demand from any other
appliances in the house. The boiler requires at least a 22 mm gas supply pipe.
The complete installation, including the meter, must be tested for gas tightness and purged as described in BS 6891.
3.2 ELECTRICAL SUPPLY
The boiler requires a 230/240 V ~ 50 Hz mains supply, fused at 3 A
The boiler must be earthed.
There must only be one common isolator, providing complete electrical isolation, for the boiler and any external controls.
This boiler has been fitted with a supply cable, however, if it is necessary to fit a cable use PVC insulated cable not less than
0.75 mm² (24 x 0.2 mm) to BS 6500 Table 16. The boiler should be connected to a fused three pin plug and unswitched shuttered
socket outlet (both complying with BS 1363), or a fused double pole switch with a contact separation of at least 3 mm in both poles.
Wiring external to the boiler must be in accordance with the current IEE Wiring Regulations (BS 7671).
Note:
If a room thermostat is fitted, it must be suitable for 230/240 V switching.
3.3 AIR SUPPLY
The boiler does not require any air vents for cooling in the room in which it is installed or when installed in a cupboard or
compartment. The minimum clearances for servicing must always be maintained.
Note:
A cupboard or compartment used to enclose the boiler must be designed and constructed specifically for the purpose,
i.e. comply with the Building Regulations.
3.4 FLUE SYSTEM - Fig. 3
The flue system must be installed in accordance with BS 5440:1.
For horizontal flues ensure that the Easy-Flue outer duct is installed horizontally (please note that the Easy-Flue inner duct
already has a pre-determined slope towards the boiler for condensate to run back towards the boiler).
When additional flue extensions are used, ensure the flue slopes downwards towards the boiler by a minimum of 25 - 30 mm
per metre of flue.
It is recommended that horizontal flue assemblies should be supported approximately every 1.5 m with access provided to
the joints.
Flue components are available as follows:-
CD Easy-Flue 500 mm (includes 90° bend and terminal) - Part No. 6.2000510.
CD Easy-Flue 1000 mm (includes 90° bend and terminal) - Part No. 6.2001010.
CD 750 mm flue extension - Part No. 6.2000750.
CD 1000 mm flue extension - Part No. 6.2001050.
CD 100 mm flue support brackets (pack of 5) - Part No. 6.1000355.
CD 90° bend - Part No. 6.2000590.
CD 45° bend - Part No. 6.2000545.
CD Vertical flue terminal assembly. Refer to the separate installation instructions supplied with the assembly.
CD Ridge flue terminal assembly. Refer to separate installation instructions supplied with assembly.
The following methods determine the correct length of flue required.
For rear exit flue (including terminal)
L = B + 160 mm (205 mm if wall jig is used)
For side exit flue (including terminal)
L = B + C + 245 mm (min. side clearance required is 5 mm)
For vertical flue L = H - 1000 mm for vertical terminal assembly
Where L = Required flue length
B = Finished wall thickness
C = Distance from the inside wall to the side of the boiler
H = Distance from top of boiler side panel to roof position
Note: 1.
If an extra 90° bend is used, this reduces the maximum flue length by 1.3 m. Each 45° bend used reduces the
maximum flue length by 0.9 m.
2.
Under no circumstances must the flue length (including allowances for extra bends) exceed 12 metres horizontally
and 15 metres vertically.
3.
Failure to use Alpha CD flue components with the boiler will invalidate the boilers CE approval, guarantee and may
be unsafe.
4.
Further plume management flue accessories are available - refer to the Easy-Flue installation instructions.
3 GENERAL BOILER INFORMATION
Alpha CD12S/20S/28S - General Boiler Information
Summary of Contents for CD12S
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