Alpha CB24, CB28, CB, SY, C Installation Instructions

Installation Instructions

Alpha Twin Pipe Flue Systems

Suitable for use with the

Alpha CB 24/28, C and SY range of gas fired

combination boilers

after Boiler Serial No. B04500001

For Technical help or for Service call ...

ALPHA HELPLINE

Tel: [phone]

Nepicar House, London Road,

Wrotham Heath, Sevenoaks,

Kent TN15 7RS

These instructions must be read in conjunction with the Installation instructions supplied with the boiler.

Only flue components supplied by Alpha may be used with Alpha boilers, failure to comply will invalidate
the boiler's warranty and CE approval, and may be unsafe.

1 COMPONENTS AVAILABLE TO ORDER

2 INTRODUCTION

1. The flue system must be installed in accordance with BS 5440:1.

2. The boiler must be installed in accordance with the Installation and Servicing instructions supplied with the boiler.

3. The maximum equivalent flue lengths are as given below. (Refer to illustrations in section 3).
Alpha Boiler

Horizontal Flue
Vertical Flue (Inc. Terminal)

Note: Ensure the flue length does not exceed the equivalent shown in the table above.

4. Each 90° Bend (80 mm) is equivalent to 1.0 m of flue length.

Each 45° Bend (80 mm) is equivalent to 0.5 m of flue length.
Note: i) Up to a maximum of four bends (90° or 45°) per flue exhaust or air inlet duct may be used.

ii) A 90° bend must not be used with a vertical flue.

5. Refer to the flue options shown to determine the equivalent length of flue pipe required. Ensure that this does not

exceed the maximum equivalent flue length given in the table above.

6. The vertical flue terminal is equivalent to 1 m of flue length and must be positioned above the roof line as shown in Fig. 3.

7. If a bend is to be fitted directly to the boiler, a clearance of 260 mm is required above the boiler.

8. Refer to the Installation and Servicing instructions supplied with the boiler for details of permissible flue terminal positions

9. For horizontal flues ensure there is a slight downward slope towards the terminal and there is no part of the flue system where

condensate will collect. Where flue lengths are more than 6 m, consideration should be given to fitting a condensate trap.

10. All parts of the exhaust flue duct must be at least 25 mm from any combustible material. When passing through a wall,

floor or roof, the flue duct must be separated from any combustible material or plastic by a non-combustible sleeve
providing a circular air space of at least 25 mm around the flue duct.

11. Any portion of the flue duct which could be touched must be encased or shielded to prevent access. This does not apply

to the air inlet duct.

CB/SY range

10 m

7 m

Twin Pipe Flue Systems

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3 FLUE OPTIONS

3.1 HORIZONTAL FLUE OPTIONS - Lmax = 10 m

L = Equivalent length of flue or air duct (a 90° bend is equivalent to 1.0 m of flue length and a 45° bend is equivalent to 0.5 m
of flue length).

Note: No more than four bends (90° or 45°) must be used on the flue exhaust or air inlet duct.
A = Total length of flue/air ducting required.

Fig. 1

Fig. 2

Twin Pipe Flue Systems

3