Alpha Alpha CD13R User guide

Installation and Servicing
Instructions
Alpha CD13R,18R and 24R
Wall Mounted, Fan Assisted, Room Sealed, Gas Fired,
High Efficiency Condensing Regular Boiler Range
Alpha CD13R G.C. No. 41 532 05
Alpha CD18R G.C. No. 41 532 03
Alpha CD24R G.C. No. 41 532 04
British Gas
Service Listed
For use with Natural Gas only
Leave these instructions with the User
Nepicar House, London Road,
Wrotham Heath, Sevenoaks,
Kent TN15 7RS
For Technical help or for Service call ...
ALPHA HELPLINE Tel: [phone]
website:www.alpha-innovation.co.uk

2Alpha CD13R, 18R, 24R - Contents/Introduction
CONTENTS
1 Introduction ....................................... 2
2 Technical data................................... 3
3 General boiler information.................. 6
4 Installation......................................... 12
5 Commissioning ................................. 18
6 Boileroperation ................................. 20
7 Routineservicing............................... 21
8 Component replacement ................... 23
9 Wiring diagrams ................................ 27
10 Fault finding ...................................... 29
11 Short parts list ................................... 32
12 Benchmark Checklist ........................ 33
13 Service record ................................... 34
The Alpha CD Regular range of high efficiency condensing boilers are wall mounted, fan assisted room-sealed boilers. The
burner is lit electronically and the heat output is controlled by a modulating fan and gas valve.
The boilers provide heating only for open vented systems and with the addition of a sealed system kit for sealed central
heating systems.
The boilers are designed for use with a fully pumped open vented or sealed and pressurised central heating system using only
Natural gas.
The boiler CD13R is suitable for central heating loads of between 5.4 and 13.1 kW (18 400 and 44 700 Btu/h).
The boiler CD18R is suitable for central heating loads of between 5.4 and 19.6 kW (18 400 and 66 800 Btu/h).
The boiler CD24R is suitable for central heating loads of between 6.5 and 25.6 kW (22 200 and 87 300 Btu/h).
The boilers are rated to the SEDBUK efficiency band A and have a NOx class 5 rating.
IMPORTANT
It is the law that all gas appliances are installed by a competent person, ie CORGI registered personnel, in accordance with
the following recommendations:-
Current Gas Safety (Installation and Use) Regulations
All current Building Regulations issued by the Department of the Environment, i.e. Approved Document L1.
Building Standards (Scotland) (Consolidation) Regulations issued by the Scottish Development Department
Health & Safety Document No. 635 (The Electricity At Work Regulations 1989)
The installation should also be in accordance with the following British Standard Codes of Practice:-
BS 5440:1:2008 Flues
BS 5449:1990 Forced circulation hot water systems
BS 5546:2000 Installation of hot water supplies for domestic purposes
BS 6700:1997 Design, installation, testing and maintenance of services supplying water
BS 6798:2000 Installation of gas fired boilers
BS 6891:1998 Gas installation
BS 7593:2006 Code of Practice for treatment of water in heating systems
BS 7671:2001 Requirements for electrical installations, IEE Wiring Regulations
Reference should also be made to the DEFRA document 'Guide to condensing boiler installation assessment procedure for
dwellings'
If installation is in a timber framed building, refer to the Institute of Gas Engineers document IGE/UP/7.
This appliance meets the requirements of IPX4D, ie degree of protection against moisture.
Failure to install this appliance correctly could lead to prosecution. It is in your own interest and that of safety to ensure that the
law is complied with.
Manufacturer's instructions must NOT be taken in anyway as over-riding statutory obligations.
Notes: 1. Ensure that the Benchmark Checklist has been completed after the boiler has been installed and commissioned.
2. Ensure the appliance has been supplied with an Alpha CD flue system.
1 INTRODUCTION

3
2.1 PERFORMANCE - NATURAL GAS (CAT: 12H 2H - G20 - 20 mbar)
2 TECHNICALDATA
Alpha CD13R, 18R, 24R - Technical Data
Alpha CD13R
MAX.
13.8
47 000
12.4
42 300
13.1
44 700
12.1
41 300
1.7
0.68
1.31
46.2
MIN.
6.2
21 100
5.6
19 100
5.9
20 100
5.4
18 400
0.4
0.16
0.6
21.2
Room sealed
chamber panel
fitted
Central Heating
Heat Input (Hs)kW
(Gross) Btu/h
Heat Input (Hi)kW
(Net) Btu/h
Heat Output (Hscondensing) kW
(50°C/30°C) Btu/h
Heat Output (Hinon-condensing) kW
(80°C/60°C) Btu/h
Differential Burner mbar
Pressure in wg
Gas Rate m³/h
ft³/h
Alpha CD18R
MAX.
20.4
69 600
18.4
62 800
19.6
66 800
18.0
61 400
3.54
1.42
1.94
68.5
MIN.
6.2
21 100
5.6
19 100
5.9
20 100
5.4
18 400
0.4
0.16
0.6
21.2
Room sealed
chamber panel
fitted
Central Heating
Heat Input (Hs)kW
(Gross) Btu/h
Heat Input (Hi)kW
(Net) Btu/h
Heat Output (Hscondensing) kW
(50°C/30°C) Btu/h
Heat Output (Hinon-condensing) kW
(80°C/60°C) Btu/h
Differential Burner mbar
Pressure in wg
Gas Rate m³/h
ft³/h
Alpha CD24R
MAX.
26.6
90 700
24
81 900
25.6
87 300
23.5
80 200
5.6
2.24
2.54
89.7
MIN.
7.5
25 600
6.8
23 200
7.2
24 600
6.5
22 200
0.6
0.24
0.72
25.4
Room sealed
chamber panel
fitted
Central Heating
Heat Input (Hs)kW
(Gross) Btu/h
Heat Input (Hi)kW
(Net) Btu/h
Heat Output (Hscondensing) kW
(50°C/30°C) Btu/h
Heat Output (Hinon-condensing) kW
(80°C/60°C) Btu/h
Differential Burner mbar
Pressure in wg
Gas Rate m³/h
ft³/h
Central Heating (Sealed System)
Max. Working System Pressure
Min. System Pressure
Max. System temperature
Pressure Relief Valve Setting
Expansion Vessel Size (pre-charge press.)
Flow Connection
Return Connection
Relief Valve Connection
Recommended System Pressure (cold)
CH Water Temp. (Approx. max.)
2.5 bar
0.5 bar
82°C
3 bar (44 PSI)
8 L at 1.0 bar
22 mm
22 mm
15 mm
1.0 bar
80°C (176°F)
2.2 SEALED SYSTEM
Note: Refer to Fig. 5 when using with a fully
pumped open vented system.
Burner
Main Heat exchanger
Main Burner Injector CD13R/18R
CD24R
Flue - Outer Duct
Flue - Inner Duct
2.3 COMPONENTS 2.4 ELECTRICAL
Supply
External Fuse
Power Consumption
Internal Fuse
Electrode Spark Gap
230/240 V ~ 50 Hz
3 A
55 W
F2 A
3 - 4 mm
Stainless steel
Stainless steel
5.1 mm
5.25 mm
White
Plastic
Note: When installed using a sealed heating system, a sealed system kit must be fitted.

4
L
N
1
2F2A
3
4
L
N
Alpha CD13R, 18R, 24R - Technical Data
Fig. 1
600 mm
390 mm
305 mm
15 mm
22 mm
1.6 L
100 mm
60 mm
Case Dimensions Height
Width
Depth
Gas Connection CD13R/18R
CD24R
Primary Water Content
Air Duct Diameter
Flue Duct Diameter
2.6 GENERAL
2.7 FLUE LENGTHS
CD Easy-Flue 500 mm with terminal and 90° bend. A CD Easy-Flue 1000 mm with terminal and 90° bend is also available.
CD 750 mm and CD 1000 mm flue extensions are available.
Length of Flue Required:-
Rear Flue (includes terminal) = wall thickness + 170 mm (or 140 mm for CD24R)
Side Flue (includes terminal) = wall thickness + distance between wall and side of boiler + 200 mm
Vertical Flue = distance from top of boiler side panel to required roof position minus 1 m for vertical terminal assembly
Maximum horizontal flue length = 12 m.
Maximum vertical flue length including terminal is 15 m.
Each additional CD 90° Bend is equivalent to 1.3 m of flue length.
Each CD 45° Bend is equivalent to 0.9 m of flue length.
The CD Vertical Flue terminal assembly is equivalent to 1 m of flue length.
2.8 PRESSURE LOSS ACROSS BOILER
Boiler terminal block
Clock connections
2.9 ELECTRICAL CONNECTIONS
Note: This Appliance Must Be Earthed
An optional integral two channel Clock kit (Part No. 6.1000220) is available if required.
Note: Only use the Alpha two channel clock. Do not fit any single channel clocks.
Min. Clearances for Servicing Top
(from casing) Bottom
Sides
Front
Flue Terminal Size
Flue Terminal Protruding
Hole Size Required For Flue Assy.
Lift Weight CD13R/18R
CD24R
2.5 INSTALLATION
235 mm
100 mm
5 mm
450 mm
100 mm Dia.
100 mm
110 mm Dia.
27 kg
28 kg
1. Ensure wires are connected
correctly
2. Only fit the Alpha recommended
2 channel clock. Other clocks
could cause damage.
WARNING
12345
Internal 2 Channel Clock Terminals
White
wire Grey
wire Black wire Blue wire Brown wire
Fuse - Always fit fast blow 2 A
230/240 V ~ 50 Hz
Fuse supply 3 A
Note: To connect external
control, remove link from
terminals 1 and 2 and
connect a 230/240 V
switched live to terminal 1
0
0 200 300100 400 500 600 700 800 900 1000
0.5
1.0
1.5
2.0
2.5
Flow rate (litres/hr)
Pressure loss
(metres head of water)
20°C System design
temperature difference
Note: The pump must
always be connected
to this terminal block
Live (Brown wire)
Neutral (Blue wire)
Earth (Green/Yellow wire)
Switched Live
230/240 V (Ch1 ON)
External Pump
Ch1 OFF
Ch2 ON
Live (Brown wire)
Neutral (Blue wire)
Earth (Green/Yellow wire)
Use only when internal
clock is fitted

5
2.10 BOILER SCHEMATIC
Alpha CD13R, 18R, 24R - Technical Data
1 - Flue sampling point
2 - Flue thermostat
3 - Injector
4 - Gas valve
5 - Primary return temperature sensor
6 - Venturi
7 - Main burner
8 - Primary/condensing heat exchanger
9 - Room sealed chamber
10 - Fan
11 - Pressure differential test points
Fig. 2
12 - Flue hood
13 - Overheat thermostat
14 - Primary flow temperature sensor
15 - Drain point
16 - Ignition electrodes
17 - Flame sensing electrode
18 - Venturi negative point
19 - Venturi positive point
20 - Gas service cock
21 - Condensate trap
Gas Condensate
discharge
Primary
Heating
return
Primary
Heating
flow
20
4
1
-
-
+
+
10
21
11
214
16
3
12
8
717
18
6
19
9
15 13
5

6
3.1 GAS SUPPLY
The CD13R boiler requires a gas rate of 1.31 m³/h (46.2 ft³/h).
The CD18R boiler requires a gas rate of 1.94 m³/h (68.5 ft³/h).
The CD24R boiler requires a gas rate of 2.54 m³/h (89.7 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 CD13R and CD18R require at least a 15 mm gas supply pipe and the CD24R requires a 22 mm
gas supply pipe.
The complete installation, including the meter, must be tested for gas soundness 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 the flue assembly is horizontal and the inner duct is sloping downwards towards the boiler.
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 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.
The following methods determine the correct length of flue required.
For rear exit flue (including terminal) L = B + 170 mm (or 140 mm for CD24R)
For side exit flue (including terminal) L = B + C + 200 mm (min. side clearance required is 5 mm)
For vertical flue L = H minus 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
only 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 CD13R, 18R, 24R - General Boiler Information

7
HORIZONTAL FLUE OPTIONS - Lmax = 12 metres
L = B + C + E + 200 mm
Alpha CD13R, 18R, 24R - General Boiler Information
L = B + C + 200 mm
CB
E
CB
E
B
F
B
C
L = B + E + F + 200 mm + (90° bend = 1.3 metre)
L = B + C + 200 mm + (2 x 45° bends = 1.8 metre)
Fig. 3
VERTICAL FLUE OPTIONS
Not less than
300 mm
Not less than
300 mm
H
Hmax=15m
Not less than
300 mm
Not less than
300 mm
H
Hmax = 13.2 m

8
A Directly below an opening, air brick, windows, etc.
B Below gutters, soil pipes or drain pipes
C Below eaves
D Below balconies
E From a vertical drain pipe or soil pipe
F From an internal or external corner
G Above ground, roof or balcony level
H From a surface facing the terminal
I From a terminal facing the terminal
J Above an opening, air brick, window etc.
K Vertically from a terminal on the same wall
L Horizontally from a terminal on the same wall
M Horizontally from an opening, air brick, window etc.
Min. distance (mm)Terminal position
Note: Incertainweather conditions the terminal will emit a plume of steam. If possible avoid positioning the terminal where this maycause
a nuisance, i.e. positions A, D, G, H, J or M.
The flue terminal must be exposed to the external air and the position must allow the free passage of air across it at all times.
If the terminal is fitted within 850 mm of a plastic or painted gutter or 450 mm of painted eaves, an aluminium shield at least 1 m
long should be fitted to the underside of the gutter or painted surface. A terminal must not be sited below 2 m where people
have access to, such as public footpaths, access routes, patios etc. However, If the terminal is fitted less than 2 m above a
surface where there is no public access, the terminal must be protected by a terminal guard.
A suitable guard is available from Alpha Therm Ltd.
For further information refer to BS 5440 Pt1:2008.
3.6 BOILER LOCATION
The boiler is not suitable for external installation, unless it is installed within a purpose designed weatherproof building.
The boiler must be installed on a flat vertical wall which is capable of supporting the weight of the boiler. The boiler can be fitted
to or adjacent to a wall comprising of a combustible material without the need for a special thermal insulation barrier.
If the boiler is to be fitted in a timber framed building, it should be fitted in accordance with the Institute of Gas Engineers 'Guide
for Gas Installations in Timber Frame Housing', reference IGE/UP/7.
The boiler may be installed in any room or internal space, although particular attention is drawn to the requirements of the
current IEE Wiring (BS7671) Regulations, and in Scotland, the electrical provisions of the Building Regulations applicable in
Scotland, with respect to the installation of the boiler in a room or internal space containing a bath or shower. Where a room-
sealed boiler is installed in a room containing a bath or shower, it must not be possible for a person using the bath or shower
to touch any electrical switch or boiler control utilising mains electricity.
The boiler may be installed in a cupboard or compartment, provided it is correctly designed for that purpose, i.e. complies with
the Building Regulations and the requirements of BS 6798.
Alpha CD13R, 18R, 24R - General Boiler Information
300 (See Note 1)
75 (See Note 3)
200 (See Note 3)
200 (See Note 3)
150 (See Note 3)
300 (See Note 2)
300
600 (See Note 4 & 5)
1200 mm
300 (See Note 1)
1500 mm
300 mm
300 mm (See Note 1)
Note: A terminal must not be sited under a car port roof
Notes: 1.In addition, the terminal should not be nearer
than 150 mm to the framework of an
opening into the buiding, i.e. a window
surround or door surround.
2.This clearance may be reduced to 25 mm
without effecting the performance of the
boiler. However, to ensure the condensate
plume does not affect adjacent surfaces a
clearance of 300 mm is preferable.
3.These clearances may be reduced to 25 mm
without effecting the performance of the
boiler. However, to ensure the condensate
plume does not affect adjacent surfaces the
terminal should be extended beyond gutters,
pipes, eaves, balconies etc.
4.It is recommended the terminal should not
be less than 2000 mm from boundary walls,
fences etc. if the plume is likely to cause a
nuisance.
5.This distance may be reduced to 300 mm if
terminal is not facing the boundary.
Fig. 4
3.5 FLUE TERMINAL LOCATION - Fig. 4

9
3.7 CENTRAL HEATING SYSTEM - Fig. 5 and 5a
The boiler is designed for use in an open or (if the alpha sealed system kit is used) sealed central heating system in accordance
with the requirements of BS 5449 and BS 6798.
Alpha CD13R, 18R, 24R - General Boiler Information
Fig. 5 - Open system with Y-Plan
Fig. 5a - Sealed system with Y-Plan
3.8 FILLING THE OPEN VENTED CENTRAL HEATING SYSTEM
A minimum head of 1 m is required between the boiler/pump and the feed and expansion tank.
The boiler must be supplied from an unrestricted water supply taken from a feed and expansion cistern situated at a maximum
height of 27 m above the boiler.
The cold feed must be 15 mm minimum size. The vent should be 22 mm in size, rise continuously and be unrestricted.
It is important that the relative positions of the pump, cold feed and open vents are as shown in Fig. 5.
The domestict hot water cylinder must be of the fully indirect coil type.
Pump
Boiler
DHW storage
cylinder
Mid position
3-portvalve
Automatic
by-pass valveBalancing
valve
Manual air vents
Pressure
gauge
Expansion
vessel
Discharge
pipe
Double
check valve
Filling point
Abovehighest
point of system
Make-up
vessel
Boiler
150mm max
1000mm minheight
Feed and
expansion tank
Vent (22mm min)
Cold feed
(15mm min)
Pump
DHW storage
cylinder
Mid position
3-portvalve
Automatic
by-pass valveBalancing
valve
450mm minheight

10
3.10 FLUSHING THE HEATING SYSTEM
It is essential that the central heating system is thoroughly cleaned and flushed when fitting an Alpha CD boiler. Failure to do so
will invalidate the warranty.
The primary and condensing heat exchanger is constructed in stainless steel and therefore is compatible with most materials
used in a heating system.
If a cleaning agent and inhibitor are used, they must be applied in accordance with their manufacturers instructions. Only
products from Fernox and Sentinel are acceptable for use with the Alpha CD boilers. Further information can be obtained from
Fernox (Tel: [phone]) or Sentinel (Tel: [phone]).
The system should be flushed in accordance with BS 7593 and BS 5449. The following procedures are recommended:
1. Installing onto a new system:-
a.Fill the system, vent at high points, at pump and radiators.
b.Check for leaks.
c.Rapidly drain the system.
d.If required, chemically clean the system as instructed by the recommended cleaner manufacturer.
Note: Ensure that the system is flushed to remove any remains of the cleaner.
e.If chemical cleaner is not used to clean the system:-
i) Refill the system.
ii) Switch on the boiler and allow the system to heat up to the normal operating temperature.
iii) Rapidly drain the system while the water is still hot.
iv) Refill the system.
f. As required, add the recommended inhibitor to the system as instructed by the inhibitor manufacturer.
g.Recheck for leaks.
2. Installing onto an existing system, clean the system before fitting the new boiler:-
a.If the old boiler is still working:-
i) Switch on the boiler and allow the system to heat up to the normal operating temperature.
ii) Rapidly drain the system while the water is still hot.
iii) Refill and chemically clean the system as instructed by the recommended cleaner manufacturer.
iv) Ensure the system is flushed to remove any remains of the cleaner.
v) Fit the new boiler.
b.If the old boiler is not working:-
i) Rapidly drain the system.
ii) Remove the old boiler.
iii) Flush the system through.
iv) Fit the new boiler.
v) Refill and chemically clean the system as instructed by the recommended cleaner manufacturer.
vi) Ensure the system is flushed to remove any remains of the cleaner.
c.As required, add the recommended inhibitor to the system as instructed by the inhibitor manufacturer.
d.Check for leaks.
Alpha CD13R, 18R, 24R - General Boiler Information
3.9 FILLING THE SEALED CENTRAL HEATING SYSTEM - Figs. 6, 7
Thesystem designpressure (cold)should beset to1.0bar.Thispressure isequivalent toa statichead(seeFig.5)of10.2 metresof water.
Provision should be made to replace water lost from the system. This can be by manual or automatic means, as shown in Figs.
6 and 7. The position for connecting an automatic make-up vessel is indicated in Fig. 5a. A double check valve assembly must
be used, as shown in Fig. 7.
Filling of the system must be carried out in a manner approved by the local Water Undertaking. Where allowed, the system
may be filled via a temporary connection as shown in Fig. 6. After filling, always disconnect the flexible hose of the filling loop.
All fittings used in the system must be able to withstand pressures up to 3 bar.
Drain taps (to BS 2879) must be used to allow the system to be completely drained.
Fig. 6 Fig. 7
Filling loop
temporarily connected
Heating circuit
return Mains
water
supply
Stop
valve
Hose
unions
Stop
valve
Double check
valve assembly
Test cock
Feed cistern to be
located above highest
point in the system
Mains
water
supply
Stop
valve
Test cock
Double check
valve assembly
Overflow
Heating circuit
return

11
Alpha CD13R, 18R, 24R - General Boiler Information
3.11 DISPOSAL OF CONDENSATE
Provision must be made for the safe disposal of condensate produced by the flue gases of the Alpha CD boilers and reference
should be made to BS 6798: 2000 for the requirements on the disposal of condensate.
The boilers incorporate a condensate trap which has a seal of 75 mm, therefore no additional trap is required.
The condensate should ideally be discharged internally into an internal waste pipe (washing machine/sink waste) or soil pipe to
avoid the possible risk of freezing. The pipework must be in 22 mm pipe.
External pipe runs should be avoided, but if it is necessary, the pipework should be protected from the risk of freezing with
waterproof insulation and the length should be kept to a maximum of 3 m. Alternatively the condensate pipework could be
increased to a minimum of 32 mm diameter without the requirement to insulate the pipework. Termination should be into an
external gulley or soakaway as shown in Figs. 8 and 9.
Note: All pipework must have a continuous fall (see Figs. 8 and 9) from the boiler and must be of an acid resistant material
such as plastic waste pipe. (copper or steel is not suitable).
It should be noted that the connection of a condensate pipe to a drain may be subject to local building control requirements.
Fig. 9 - External soakaway
Fig. 8 - External gully
Open endof pipe
divertedinto gully
below grid butabove
waterlevel
Use waterproof
pipework insulation
invery exposed
positions
Ensurepipeis
adequatelysupported
Plastic pipe
Minimumgradient 2½°

12 Alpha CD13R, 18R, 24R - Installation
4 INSTALLATION
4.1 UNPACKING
1. The boxes required when the boiler is installed with a horizontal flue are as follows:-
Box 1 Cased boiler fitted with gas isolation valve, gas union and washers
Mounting bracket plus screws and wall plugs, 15 mm gas union bend
Literature pack and Wall template
Box 2 CD Easy-Flue 500 mm or CD Easy-Flue 1000 mm. Both include 90° bend and horizontal flue terminal
Note: NOT required for vertical flue
Notes: a. All flues must be suitable for CD condensing boilers.
b. CD 750 mm and 1000 mm flue extensions are available, if required.
2. Unpack boiler and remove the loose items packs and mounting bracket.
Note: To prevent any damage being caused, ensure the gas union bend is removed before standing the boiler in an
upright position.
4.2 CLEARANCES REQUIRED - Fig. 10
Fig. 10
4.3 PREPARE THE WALL - Figs. 11, 12
1. Decide upon the position of the boiler taking
into account the clearances required for
servicing and the flue terminal position.
2. Tape the template to the wall (ensure it is
level and the right way up) and mark the
position of the holes for the boiler mounting
bracket and bottom fixings. If rear exit flue is
used, mark the position of the hole for the
flue.
3. Side exit flue - Continue the horizontal centre
line of the flue across the wall to the side wall,
thenalongthe side wall 160 mm for the CD13R
and CD18R or 130 mm for the CD24R (ensure
thelinesarehorizontal).Thiswillgivetheposition
of the centre of the hole for the flue.
4. Cut the 110 mm diameter hole (or use a 107
mm core drill) in the wall for the flue.
Notes: a. Ensure the hole is horizontal.
b. Forinternalfittingoftheflue,using
thefluesealingcollarsupplied,cuta
130 mm dia. flue hole using a 127 mm core drill.
5. Drill the fixing holes (10 mm dia.) to accept the No.10 plugs supplied. Using the screws supplied, fit the mounting bracket.
Fig. 11
Bottom
fixing holes
Template
Outline of
boiler
Ensure line is levelRear exit hole
110 mm dia.
Position of
110 mm hole
to be cut for
side exit flue
160 mm CD13R/CD18R
130 mm CD24R
==
Wall
mounting
bracket
fixing holes
135 mm

13
Fig. 13
A- Gas valve
B- Gas isolating valve
C- Condensate trap
4.4 FIT THE BOILER - Refer to Fig. 11
1. Lift the boiler and locate it on the mounting bracket. Fit the bottom screws to secure the boiler in position.
Alpha CD13R, 18R, 24R - Installation
Fig. 12
4.5 CONNECT THE PIPEWORK - Fig. 13
1. Thoroughly flush out all the water pipework. Refer to Section 3.9.
2. The gas isolation valve has been factory fitted, however, check that the connections underneath the boiler have been
tightened.
Note: When soldering to the boiler union bend, ensure the bend is not connected to the valve, otherwise the internal seals
may be damaged.
3. Connect the system pipework to the boiler.
Note: Ensure the flow and return pipes are correctly connected to the boiler. Refer to Fig. 12.
4. Connect the 22 mm condensate trap drain pipe to the condensate discharge pipe.
Ensure that the condensate discharge pipe is as required in Section 3.11.
Pour at least 0.5 litre of water into the flue duct, as shown in Fig. 12, and check the condensate discharge pipe for soundness.
5. Ensure that the gas isolation valve is closed (spindle flats at right angles to valve) and do not turn on the gas supply at this stage.
A
B
C
20
235 105 50
85
Pour water into flue duct
Rear view of boiler
Boiler locating
bracket
CH flow
CH return

14
4.6 FIT THE FLUE - Figs. 14, 15
The following procedure applies to fitting an Alpha CD Easy-Flue to both rear or side exit flue - horizontally only.
1. The CD Easy-Flues are suitable for use in the flue length ranges shown in the tables below.
Note: Where the length is less than the minimum or more than the maximum, refer to Section 4.7.
Alpha CD13R, 18R, 24R - Installation
Fig. 14 Fig. 15
2. Determine the overall length (L) of flue required, (see Fig. 16) as follows:-
Rear flue L = wall thickness (B) + 90 mm for CD13/18R or 60 mm for CD24R
Side flue L = wall thickness (B) + distance between boiler and wall (C) + 120 mm
Fig. 16
3. Adjust the telescopic section of the flue to the distance 'L', ensuring that the two labels marked 'TOP' are aligned, then seal
and secure the joint between the ducts with the sealing tape supplied.
4. Pass the flue assembly through the wall (from inside or outside).
Note: Internal fitting - If there is no access to make good the outside wall, locate the flue sealing collar onto the outer duct
of the flue immediately before the terminal grille onto the location provided. Push the flue assembly through the 130 mm flue
hole, so that the collar completely passes through the wall. Then pull the flue assembly back into the correct position. Visually
check that the collar is sealing the outside wall and that it is not restricting any of the openings of the flue terminal.
Fig. 17 - Fitting the flue from inside
5. Position the seal and clamp (two screws) supplied, over the bend. Fit the bend to the boiler and rotate to the correct position.
Secure in position using the seal and clamp, ensuring the seal is located centrally over both the bend and boiler adaptor.
6. Fit the inside flue sealing collar over the Easy-Flue. Fit the outside flue sealing collar onto the flue immediately before the
terminal grille onto the location provided.
CD Easy-Flue
500 mm
1000 mm
Max
475
920
Min
285
710
B + C (mm)CD Easy-Flue
500 mm
1000 mm
B (mm)
13R/18R
515
960
13R/18R
325
750
24R
545
990
24R
355
780
Max Min
RearFlue
(B)
SideFlue
(B+C)

15
Fig. 18 - Rear flue
Alpha CD13R, 18R, 24R - Installation
f. Slide the clamp (three screws) over the outer duct and pull the flue assembly towards the bend, locating the inner duct into
the seal joint on the bend. Ensure the labels marked 'TOP' are positioned at the top before securing the flue assembly to
the bend with the clamp (three screws) located centrally over the joint.
Note: Check the flue terminal protrudes 90 mm out of the wall and the inner duct of the terminal is positioned correctly
(see Fig. 18).
g. Make good the inside wall by pushing the inside flue sealing collar up to the wall.
4.7 EXTENDING THE FLUE - Fig. 19
Note: The maximum horizontal flue assembly length must not exceed a length of 12 metres.
1. When the flue length required is more than the maximum or less than the minimum stated in Section 4.6, paragraph 1,
refer to the table below.
90
Outer ductclamp
Inner ductseal joint
Inner ductseal joint
90° bend
Terminal
Fluesealing collar
Note: Ensurethe outer flueductishorizontal
Boiler side
CD Easy-Flue
Ensurethe inner ductwithin
the terminal isat the top.
The inner ductmust
bepositioned to slopetowards
the boiler
Note:
CD13R/18R
CD24R
160mm
130 mm
CD13R/18R
CD24R
65 mm
35 mm
2. Use the template (supplied with the boiler) to mark the required flue position and cut a 130 mm diameter hole for the flue
(use a 127 mm core drill). The size of the hole provides sufficient clearance for the clamps on the flue extension to pass
through the hole.
Flue Length
CD13R/18R Up to:-
CD24R Up to:-
CD13R/18R Between:-
CD24R Between:-
CD13R/18R Between:-
CD24R Between:-
CD13R/18R Between:-
CD24R Between:-
CD13R/18R Between:-
CD24R Between:-
Less than above
Rear Flue (B)
11.93 m max
11.96 m max
740 mm and 945 mm
770 mm and 975 mm
95 mm and 685 mm
125 mm and 715 mm
300 mm and 505 mm
330 mm and 535 mm
95 mm and 245 mm
125 mm and 275 mm
Side Flue (B + C)
11.89 m max
11.89 m max
700 mm and 905 mm
700 mm and 905 mm
55 mm and 645 mm
55 mm and 645 mm
260 mm and 465 mm
260 mm and 465 mm
55 mm and 205 mm
55 mm and 205 mm
Comments
Alpha CD 750 mm or 1000 mm flue extension
(Part No. 6.2000750 or 6.2001050) is required to
extend the range of telescopic flue.
Refer to Section 4.7 paragraph 2 for instructions
on how to extend the flue.
Note: A 130 mm flue hole (127 mm core drill) is
required in the wall.
Within the standard Easy-Flue 1000 mm
(Part No. 6.2001010) telescopic range.
Discard the first telescopic section of the Easy-Flue
1000 mm (i.e. not with terminal) and cut to the required
length
Within standard Easy-Flue 500 mm
(Part No. 6.2000510) telescopic range.
Discardthe firsttelescopic section of the Easy-Flue500
mm(i.e.notwithterminal)andcuttotherequiredlength.
Terminalmayprotrude somewhatfromthe outsidewall.

16
3. Determine the overall flue length as described in Section 4.6, paragraph 2 to determine the number of Alpha CD 750/1000
mm flue extensions required.
4. Assemble the flue extensions together by locating the inner duct into the seal joint and secure each extension together
with the clamps supplied (three screws). Ensure that the clamps are positioned centrally over the joints.
Note: If it is required to cut an extension, DO NOT cut the end of the inner duct that incorporates the seal joint. Ensure the
inner duct end without the seal joint is cut so that it is 15 mm longer than the outer duct.
5. Adjust the telescopic section of the Easy-Flue to the required length and secure the Easy-Flue with the sealing tape
supplied. Fit the Easy-Flue to the extensions by locating the inner duct into the seal joint and secure with the clamp (three
screws), ensuring it is located centrally over the joint.
6. Mark the end of the flue assembly 'TOP' where it is connected to the boiler,so that the 'TOP' of the flue terminal is aligned
with the 'TOP' at the boiler end of the flue assembly.
7. Pass the complete flue assembly through the wall.
8. Position the seal and clamp (two screws) supplied, over the bend. Fit the bend to the boiler and rotate to the correct position
and secure in position using the seal and clamp, ensuring that the seal is positioned centrally over both the bend and adaptor.
9. Slide the clamp (three screws) over the outer duct and pull the flue assembly towards the bend, locating the inner duct into
the seal joint on the bend.
10. Secure the flue assembly to the bend with the clamp (three screws) ensuring it is positioned centrally over the joint,
ensuring the 'TOP' marked on the outer duct is positioned at the top.
Note: Check the flue terminal protrudes 100 mm out of the wall and that the inner duct of the terminal is positioned
correctly, i.e. the inner duct within the terminal is at the top. See Fig. 19.
11. Make good the outside wall by fitting a flue sealing collar onto the location provided immediately behind the flue terminal
grille. Make good the inside wall as required.
Note: If flue sealing collars are being used to make good the inside wall, then they will need to be fitted before assembling
the flue.
Alpha CD13R, 18R, 24R - Installation
Fig. 19 - Side flue
195 mm
100 mm
90
45
Note: Ensurethe flueextension slopes
downwardstowardsthe boiler by a
minimumof 25 - 30 mm per metre
Boiler front
Outer ductclamp
Inner seal joint
Inner seal joint
Fluelength (L)
Clamp
and seal
90° bend
Seal joint
CD Easy-Flue
CD Flueextension
Fluesealing
collar
Flue
terminal
Ensurethe inner ductwithin
the terminal isat the top.
The inner ductmust
bepositioned to slopetowards
the boiler
Note:

17
Fig. 21
Alpha CD13R, 18R, 24R - Installation
4.8 CONNECT THE MAINS SUPPLY - Fig. 20
1. Gain access to the boiler terminal block by removing one
screw at the top centre of the front panel, then lift up and
remove panel. Release the two fixing screws (one each
side) securing the control panel. Lower the control panel.
Referto TechnicalData, Section2.9forconnectiondetails.
2. Note:Thisboilerhasbeenfittedwithamainssupplycable.
However,if it is necessarytofit an alternative supplycable,
ensurethecable clampthat hasbeenfittedisremovedand
connect as follows:-
Remove the two screws securing the terminal block cover
from the back of the control box (see Fig. 20). Pass the
mains supply cable through the grommet and cable clamp
and connect as follows:- Brown to L, Blue to N and Green/
Yellow to . Ensure correct polarity.
Note: Ensure that the length of the earth wire is such
that if the supply cable is pulled out of its clamp the live
and neutral wires become taut before the earth wire.
The main terminal block can be removed by pulling it off
the pins to give easy access to the terminals.
Do not switch on the electrical supply at this stage.
3. If an external control, i.e. room thermostat or external clock is to be fitted, remove the terminal block cover and remove the
link between terminals 1 and 2. Pass the cable through the cable clamp and connect it to terminals 1 and 2. Connect the
external pump cable to the boiler terminal block by passing the cable through the cable clamp and connecting it to L, N
and terminals for the external pump. Replace the terminal block cover. (Refer to Section 2.9).
Note: Ensure the pump is always connected to the boiler terminal block.
4. Replace the terminal block, ensuring it is located correctly on the plastic pins and replace the cover.
5. Ensurethatthereissufficientfreecabletoallowthecontrolpaneltoberaisedandloweredthentightenthecableclampscrews.
6. Leave the control panel open until commissioning procedures have been completed.
7. Carry out electrical system checks - Short circuit, Polarity, Earth continuity and Resistance to earth with a suitable multimeter.
4.9 FIT THE CLOCK KIT - Fig. 21
Ensure the electrical supply to the boiler is isolated.
Note: Only use an Alpha two channel clock. Do not fit a single channel clock.
1. Remove the two screws securing the clock cover at the rear of the control panel.
2. Remove and discard the clock blanking panel.
3. Insert the clock into the opening and secure in place with the screws supplied - do not overtighten the screws..
4. Disconnect the clock wiring from the terminal block and connect it to the clock as follows:-
Brown wire to terminal 1, Blue wire to terminal 2, Black wire to terminal 3, Grey wire to terminal 4 and White wire to terminal
5, (or as per the instructions supplied with the clock). Ensure wiring is correct.
Note: Before the clock is fitted, remove the link between terminals 1 and 3 on the clock wiring harness fitted to the boiler.
5. Replace the clock cover. Do not overtighten the fixing screws.
6. Leave the control panel open until commissioning procedures have been completed.
Rear of control panel Clock cover
Fig. 20
Terminal block cover
Fuse Cable clamps
Remove link to
connect external
controls. See
Wiring diagram
Connect external
pump. See wiring
diagram.
Note: The pump
must always be
connected to this
terminal block.
Grommets

18 Alpha CD13R, 18R, 24R - Commissioning
When commissioning the boiler, ensure the Benchmark Checklist is completed.
5.1 FILL THE SYSTEM
1. To remove the air - Vent each radiator in turn, starting with the lowest in the system.
2. Itisimportant thattheexternal pumpisproperly ventedtoavoid itrunningdry anddamagingits bearings.Unscrewand remove
the cap from the centre of the pump. Using a suitable screwdriver rotate the exposed spindle about half a turn, then replace
the cap.
3. Refer to Sections 3.8, 3.9 and 3.10 for filling and flushing the system.
4. Ensure that the condensate trap has been filled with water. Refer to Section 4.5, paragraph 4.
5.2 BOILER CONTROLS - Fig. 22
5 COMMISSIONING
Fig. 22
5.3 TEST FOR GAS SOUNDNESS AND PURGE THE SUPPLY
1. With the boiler gas service cock closed (slot at right angles to valve). Pressure test the gas supply and inlet pipework
connection to the boiler gas service cock for soundness in accordance with BS 6891.
2. Loosen the gas inlet pressure test point screw on the gas valve (see Fig. 24). Ensure the gas supply is on and open the
boiler service cock to purge in accordance with BS 6891.
3. Retighten the test point screw and test for gas soundness. Close the boiler gas service cock.
5.4 INITIAL LIGHTING - Refer to Fig. 22
1. Ensure that the gas and electrical supplies to the boiler are off.
2. Turn on the gas and electrical supplies to the boiler.
3. Ensure all external controls are calling for heat.
If the optional Clock is fitted, set the time and ensure the Clock is in an 'on' mode.
4. Set the central heating thermostat to maximum.
5. Set the selector switch to 'ON'. The boiler will now run. The external pump will start, the fan will start and the main gas
valve solenoid will open allowing the main burner to light.
5.5 CHECK THE BURNER PRESSURES - Figs. 23, 24
Turn the boiler off. Remove the two pressure test point screws at the top of the boiler and connect a differential pressure gauge
to P1 and P2 as shown in Fig 23. Allow the boiler to run for 10 minutes and check the differential burner pressures.
1. Set the selector switch to 'ON'.
2. The burner will light at the ignition rate and will increase to the factory pre-set maximum output after approximately 4 minutes.
Central
HeatingThermostat
Frost
Thermostat position
Selector Switch
0
Indicator
Neons
1
2
3
1
2
3
4
5
6
7
8
9
RESET
ON
OFF FROST
A
D
B
C
SELECTOR THERMOSTAT
CD18R

19
3. Turn off the boiler. Disconnect the pressure gauge and tighten the test point screws. Test for gas soundness using
suitable leak detection fluid.
Note: The burner pressure settings have been factory set and do not require adjusting. If incorrect, check that the
inlet gas pressure is 20 mbar.
If the inlet gas pressure is not 20 mbar, either the pipework is too small or the gas supply to the house is insufficient, in
which case contact your gas supplier. If the differential burner pressures are still incorrect contact Alpha.
Note: Refer to Technical Data, Section 2.1 for the required differential burner pressures.
Fig. 24Fig. 23
Differential
Burner
pressure
Alpha CD13R, 18R, 24R - Commissioning
5.6 FINAL COMMISSIONING
1. Allow the heating system to heat up, then balance the system to achieve the necessary temperature difference across the
heating flow and return pipes at the boiler.
2. Turn off the boiler.
5.7 FINAL ASSEMBLY
1. Raise the control panel and secure in position with the screws provided, locate the front casing panel in position and
secure with the screw at the top of the panel.
2. If the boiler is to be left in service with the User, set the controls, clock (if fitted, see Clock User's Operating manual) and
room thermostat (if fitted) to the User's requirements.
3. If the boiler is not to be handed over immediately, close the boiler gas service cock and switch off the electrical supply.
4. If there is any possibility of the boiler being left during frost conditions, then the boiler and system should be drained (refer to Section
8.2). It is recommended that a label is attached to the boiler drawing attention to the fact that the system has been drained.
5. Complete the details of the installation in the Benchmark Checklist on page 33.
5.8 USER INFORMATION
The User must be advised (and demonstrated if necessary) of the following important points:-
1. How to light and turn off the boiler and how to operate the system controls.
2. The importance of annual servicing of the boiler to ensure safe and efficient operation.
3. That any servicing or replacement of parts must only be carried out by CORGI registered personnel.
4. Ensure that the boiler controls and room thermostat (if fitted) are set to the User's requirements.
5. Tell the User that if the electrical supply is on and the boiler has not operated for 24 hours for heating, the pump will
automatically operate for 5 minutes.
6. Explain to the User that an internal frost thermostat is fitted in the boiler, and that the electrical supply to the boiler must be
left on for the thermostat to operate.
7. Explain to the User that in certain weather conditions the terminal will emit a plume of steam, i.e. water vapour. This is safe
and quite normal.
8. Show the User the position of the condensate discharge pipe.
9. Hand the User's instructions to the User.
10. Ensure the Benchmark Checklist in Section 12, page 34, has been completed after the boiler has been installed and
commissioned.
11. Leave these Installation and Servicing instructions with the User for use on future calls.

20
6.1 CENTRAL HEATING MODE
The operating sequence of the boiler is controlled by the selector switch on the control panel.
Setting the selector switch to position (2) the boiler will operate to provide central heating.
When the selector is set to central heating, it will respond to a demand for heat in the following sequence:-
a. The external pump will start, the fan will operate and the main burner will light.
b. The output of the burner is automatically controlled to suit the system demand.
c. When the temperature of the system water in the boiler reaches that set by the thermostat or the room thermostat is
satisfied, the main burner is turned off and the fan stops after 50 seconds. The pump will continue to run to remove any
residual heat from the boiler.
6.3 FROST THERMOSTAT
The boiler incorporates a built in frost thermostat which automatically turns on the boiler and pump if the water in the boiler falls
below 8°C, providing the electrical supply is on and the selector switch is set to position (1) or position (2). The boiler will
operate until the water temperature in the system reaches approximately 40°C.
6.4 PUMP
If the electrical supply is on and the boiler has not operated for 24 hours for heating or hot water, the external pump will operate
automatically for five minutes every 24 hours.
6.5 INDICATOR NEONS
When neons A (red), B (red), C (yellow), D (green) are illuminated, the following conditions apply:-
Neon
DIlluminated continuously - Electricity supply to the boiler is on.
CIlluminated continuously - Burner is alight.
AFlashing on and off - Temperature sensor fault.
BFlashing on and off - Overheat thermostat has operated. Rotate selector switch to the reset position (3) to reset.
BIlluminated continuously - Burner has failed to light. Rotate selector switch to the reset position (3) and the ignition
sequence will restart after a delay of about 30 seconds.
Aand BFlashing on and off at the same time - Blocked flue or fan fault.
AFlashing and BIlluminated continuously - Pump fault or restricted flow.
AIlluminated continuously and Bflashing - PCB or flame sensor fault.
Aand Billuminated continuously - No flow or air present
A, B and Cflashing on and off at the same time - Temperature sensor wiring or flow and return connections incorrect.
Note: Do not hold the selector switch in the reset position (3) for more than 2 to 3 seconds.
Alpha CD13R, 18R, 24R - Boiler Operation
6 BOILER OPERATION