Glowworm 24cx User manual

1
INSTALLATION AND SERVICING
High Efficiency
Condensing Combination
Boilers
Glow-worm, Nottingham Road, Belper, Derbyshire. DE56 1JT
www.glow-worm.co.uk
2000225263-02 11.05
Flexicom
30cx
G.C. No. 47-047-34
24cx
G.C. No. 47-047-33

2
Thank you for installing a new Glow-worm appliance in your home.
Glow-worm appliances are manufactured to the very highest standard so we are pleased to offer
our customers a Comprehensive Guarantee.
This product is guaranteed for 24 months from the date of installation or 30 months from the date
of manufacture, whichever is the shorter, for parts. In addition this product is guaranteed for 12
months from the date of installation or 18 months from the date of manufacture, whichever is the
shorter, for labour.
The second year of the parts guarantee, from the beginning of the 13th month onwards after
installation or manufacture, is conditional upon the boiler having been serviced by a CORGI regis-
tered gas installer,
in accordance with the manufacturer’s recommendations. We strongly recommend regular servic-
ing of your gas appliance, but where the condition is not met, any chargeable spare parts or com-
ponents issued within the applicable guarantee period still benefit from a 12 month warranty from
the date of issue by the manufacturer.
We recommend you complete and return as soon as possible your guarantee registration card.
If your guarantee registration card is missing you can obtain a copy or record your registration by
telephoning the Glow-worm Customer Service number 01773 828100.
Guarantee Registration
Customer Service:
01773 828100
Technical Helpline:
01773 828300
General and Sales enquiries:
Tel. [phone]
Fax: [phone]
To register your Glow-worm appliance
call:
0800 0732142

3
CONTENTS DESCRIPTION SECTION PAGE
Warnings 4
Important Information 4
General Information 5
Appliance Safety Devices 6
Maintenance and Servicing 6
Technical Information 1 7
Boiler Location and Ventilation 2 10
Flue Options and Terminal Clearances 3 11
Heating System 4 13
Domestic Hot Water System 5 15
Installation Preparation 6 15
Gas/Water & Appliance Connection 7 18
Safety Discharge Valve and
Condensate Connection 8 20
Flue Preparation and Installation 9 22
Electrical Connection 10 35
Commissioning 11 36
Servicing 12 38
Fault Finding 13 41
Replacement of Parts 14 47
Spare Parts 15 57
Manual Handling 16 58
INTRODUCTION
INSTALLATION
INSTRUCTIONS
The instructions consist of two parts, Installation and Servicing Instructions. The instruc-
tions are an integral part of the appliance and must, to comply with the current issue of
the Gas Safety (Installation and Use) Regulations, be handed to the user on completion of
the installation.

4
Gas Category
This boiler is for use only on G20 natural gas.
Gas Safety (Installation and Use) Regulations
In your own interests and that of safety, it is the Law that ALL
gas appliances are installed by a competent person in accord-
ance with the current issue of the above regulations.
Testing and Certification
This boiler is tested and certificated for safety and perform-
ance. It is, therefore, important that no alteration is made to
the boiler, without permission, in writing, by Glow-worm.
Any alteration not approved by Glow-worm, could invalidate
the certification, boiler warranty and may also infringe the cur-
rent issue of the statutory requirements.
CE Mark
This boiler meets the requirements of Statutory Instrument,
No. 3083 The Boiler (Efficiency) Regulations, and therefore is
deemed to meet the requirements of Directive 92/42/EEC on
the efficiency requirements for new hot water boilers fired with
liquid or gaseous fuels.
Type test for purposes of Regulation 5 certified by: Notified
body 0087.
Product/production certified by: Notified body 0086.
The CE mark on this appliance shows compliance with:
1. Directive 90/396/EEC on the approximation of the laws
of the Member States relating to appliances burning gaseous
fuels.
2. Directive 73/23/EEC on the harmonisation of the Laws of
the Member States relating to electrical equipment designed
for use within certain voltage limits.
3. Directive 89/336/EEC on the approximation of the Laws of
the Member States relating to electromagnetic compatibility.
Control of Substances Hazardous to Health
Under Section 6 of The Health and Safety at Work Act 1974,
we are required to provide information on substances hazard-
ous to health.
The adhesives and sealants used in this appliance are cured
and give no known hazard in this state.
Electrical Supply
The boiler must be earthed.
All system components shall be of an approved type and all
wiring to current I.E.E. wiring regulations.
External wiring must be correctly earthed, polarised and in
accordance with the relevant standards.
In GB this is BS 7671.
In IE this is the current edition of I.S.813 “Domestic Gas Instal-
lations”.
The boiler must be connected to a permanent 230V ac, 50Hz
supply.
Connection of the whole electrical system of the boiler,
including any heating controls, to the electrical supply must
be through one common isolator and must be fused 3 Amp
maximum.
Isolation should be by a double pole switched fused spur box,
with a minimum gap of 3mm for both poles. The fused spur
box should be readily accessible and preferably adjacent to
the appliance. It should be identified as to its use.
Alternatively connection can be made through an unswitched
shuttered socket and 3A fused 3-pin plug both to the current
issue of BS 1363, provided they are not used in a room con-
taining a bath or shower.
Wiring to the boiler must be PVC 85OC insulated cable, not
less than 0.75mm2 (24/0.20mm).
IMPORTANT NOTE
ALL electrical connections to the boiler
must be permanently fixed to a wall or a
sturdy support feature in a tidy manner.
WARNINGS
Gas Leak or Fault
Turn off the gas emergency control valve immediately. Eliminate all sources of ignition, i.e.smoking, blowlamps, hot
air guns etc. Do not operate electrical lights or switches either on or off. Open all doors and windows,ventilate the
area.
Sheet Metal Parts
This boiler contains metal parts (components) and care should be taken when handling and cleaning, with particular
regard to edges.
Sealed Components
Under no circumstances must the User interfere with or adjust sealed parts.
Important Information

5
General Information
General Note
This boiler is designed for use as part of a sealed water
central heating system with fully pumped circulation. The
pump, expansion vessel and associated safety devices are all
fitted within the boiler.
Once the controls are set the boiler operates automatically.
Please read these instructions and follow them carefully for
the correct installation and economical use of your boiler.
Water Treatment
In the case of an existing system, it is ESSENTIAL that prior
to installing the new boiler the system is thoroughly flushed.
For optimum performance after installation of a new system,
the boiler and its associated central heating system should
also be flushed. Flushing should be carried out in accordance
with BS7593: 1992 using a cleanser such as Sentinel X300
or X400, Fernox Restorer or Salamander corrosion guard
cleaner.
For long-term corrosion protection, after flushing, a suitable
inhibitor should be used, refer to the current issue of BS
5449 and BS 7593 on the use of inhibitors in central heating
systems. Examples are Sentinel X100 Fernox Protector or
Salamander corrosion guard inhibitor.
Compartment or Cupboard Installations
If the boiler is fitted into a compartment or cupboard it does
not require ventilation openings.
Do not use the compartment or cupboard for storage.
Clearances
If fixtures are positioned close to the boiler, space must be
left as shown in diagram 2.1.
Condensate Drain
The condensate drain, see diagram 8.2, must not be modified
or blocked.
Pluming from flue terminal
Like all condensing boilers this appliance will produce a plume
of condensation from the flue terminal in cool weather. This is
due to the high efficiency and hence low flue gas temperature
of the boiler. It is normal and not a fault indication.
Electrical Supply
If the mains electricity and gas are to be turned off for any
long periods during severe weather, it is recommended that
the whole system, including the boiler, should be drained to
avoid the risk of freezing.
NOTE: Contact your installation/servicing company as
draining, refilling and pressurising MUST be carried out by a
competent person.
Manual Handling
IMPORTANT: With regards to the “Manual Handling
Operations, 1992 Regulations”, the appliance exceeds the
recommended weight for a one man lift.

6
Electrical Supply Failure
The boiler will not work without an electrical supply.
Normal operation of the boiler should resume when the
electrical supply is restored.
Reset any external controls, to resume normal operation of the
central heating.
If the boiler does not resume normal operation press the reset
button. If the boiler does not resume normal operation after this
call your Installation/Servicing company.
Overheating safety
In the event of the boiler overheating the safety devices will
cause a safety shutdown. If this happens, press the reset
button.
Safety Discharge Valve
A safety discharge valve and discharge pipe is fitted to the
boiler. This valve must not be touched. Should there be any
discharge from the pipe, isolate the boiler electrical supply and
call your installer or Glow-worm’s own service organisation
using the telephone number on the inside front cover of this
booklet.
Appliance Safety Devices
Frost protection
The appliance has a built in frost protection device that protects
the boiler from freezing. With the gas and electric supplies ON
and irrespective of any room thermostat setting, the frost pro-
tection device will operate the pump when the temperature of
the boiler water falls below 8OC.
A timer is used so that the temperature can be checked periodi-
cally. After 10 minutes the pump will be stopped if the tempera-
ture is higher than 10OC or has already reached 35OC.
The burner will activate if the boiler temperature does not reach
10OC after 30 minutes or at any time if the temperature drops
to 5OC.
The burner will switch off when the temperature reaches
35OC.
Condensate Drain Blockage
As a safety feature the boiler will stop working if the condensate
drain becomes blocked. During freezing conditions this may
be due to the forming of ice in the condense drain external
to the house. Release an ice blockage by the use of warm
cloths on the pipe. The boiler should then restart. Contact your
installation/servicing company if the fault persists.
Maintenance and Servicing
Maintenance and Servicing
To ensure the continued efficient and safe operation of the
appliance it is recommended that it is checked and serviced as
necessary at regular intervals. The frequency of servicing will
depend upon the particular installation conditions and usage.
If this appliance is installed in a rented property there is a duty
of care imposed on the owner of the property by the current
issue of the Gas Safety (Installation and Use) Regulations,
Section 35.
Servicing/maintenance should be carried out by a competent
person in accordance with the rules in force in the countries
of destination.
To obtain service, please call your installer or Glow-worm’s
own service organisation using the telephone number on the
inside front cover of this literature.
Please be advised that the ‘Benchmark’ logbook, located at
centre of literature, should be completed by the installation
engineer on completion of commissioning and servicing.
Spare Parts
Remember, when replacing a part on this appliance, use
only spare parts that you can be assured conform to the
safety and performance specification that we require. Do not
use reconditioned or copy parts that have not been clearly
authorised by Glow-worm.
If a part is required contact Glow-worm’s own service
organisation using the telephone number on the inside front
cover of this booklet.
Please quote the name of the appliance, this infomation will be
on the name badge on the front of the appliance.
If in doubt seek advice from the local gas company or Glow-
worm’s own service organisation using the telephone number
on the inside front cover of this booklet.

7
167.5
6060
100
100
700
390
280
C
L
FLUE
87
19 (Gas & Domestic Water)
22.5 (Central Heating)
Flexible
Condensate
Connection
76
25
47
BOILER
C
L
RETURN
FLOW
1 Technical Information
1.1 IMPORTANT
The boiler is supplied in one carton, which includes the
appliance packs, see diagram 6.1.
The flue is supplied separately.
This boiler is for use only on G20 natural gas.
Where no British Standards exists, materials and equipment
should be fit for their purpose and of suitable quality and
workmanship.
The installation of this boiler must be carried out by a competent
person in accordance the rules in force in the countries of
destination.
Manufacturer’s instructions must not be taken as overriding
statutory requirements.
1.2 Statutory Requirements
In GB the installation of the boiler must be carried out by a
competent person as described in the following regulations:
The manufacturer’s instructions supplied.
The Gas Safety (Installation and Use) Regulations.
The appropriate Buildings Regulations either The Building
Regulations, The Building Regulations (Scotland),The Building
Regulations (Northern Ireland).
The Water Fittings Regulations or Water byelaws in Scotland.
The Health and Safety at Work Act, Control of Substances
Hazardous to Health (COSHH).
The Current I.E.E. Wiring Regulations.
Where no specific instructions are given, reference should be
made to the relevant British Standard Code of Practice.
In IE, the installation must be carried out by a competent
person and installed in accordance with the current edition
of I.S.813 “Domestic Gas Installations”, the current Building
Regulations and reference should be made to the current ETCI
rules for Electrical Installation.
In GB the following Codes of Practice apply:
BS4814, BS6798, BS5440 Part 1 and 2, BS5546 Part 1,
BS5449, BS6891, BS6700, BS7074 Part 1 and 2, BS7593,
BS7671.
In IE: I.S.813, BS5546, BS 5449, BS 7074, BS 7593.
Manufacturer’s instructions must not be taken as overriding
statutory requirements.
NOTE: For further information, see the current issue of the
Building Regulations, approved document L1 ( in the UK) and
the following current issues of:
1) Central heating system specification (CheSS)
and
2) Controls for domestic central heating system and hot water.
BRECSU.
12651
Diagram 1.1

8
1 Technical Information
1.3 Technical Data
All dimensions are given in millimetres (except as noted).
See diagrams 1.1 and Boiler Specification table.
The data label is positioned on the base of the boiler.
12994
BOILER SPECIFICATION 24cx 30cx
Lift weight 36kg (79Ib) 36kg (79Ib)
Total weight (installed) 41kg (90Ib) 41kg (90Ib
Gas connection Ø O.D. 15mm. copper 15mm. copper
Heating and return connection Ø O.D. 22mm. copper 22mm. copper
Domestic hot water connection Ø O.D. 15mm. copper 15mm. copper
Condensate connection Ø I.D. 21.5mm. plastic 21.5mm. plastic
Safety valve discharge connection Ø O.D. 15mm. copper 15mm. copper
Heating circuit PMS safety valve (preset) 3 bar (43/5Ibf/in2) 3 bar (43/5Ibf/in2)
Heating system minimum pressure 0.7bar (10.1Ibf/in2) 0.7bar (10.1Ibf/in2)
Domestic water circuit PMW 10bar (145Ibf/in2) 10bar (145Ibf/in2)
Minimum working pressure for 0.2bar (2.9Ibf/in2) 0.2bar (2.9Ibf/in2)
maximum domestic flow rate
Specific water rate at 35° rise 9.85L/min. 12.3L/min.
Minimum domestic hot water 776L/hr. 1032L/hr.
flow rate at 35° rise
Maximum domestic hot water temperature 63° 63°
Expansion vessel capacity 8 litres (1.76 gallons) 8 litres (1.76 gallons)
Expansion vessel charge pressure 0.5bar (7,3Ibf/in2) 0.5bar (7,3Ibf/in2)
Electrical supply 230V~50Hz fused 3A 230V~50Hz fused 3A
Electrical rating 180W fused 3A 180W fused 3A
EN437 IP clasification X4D X4D
Internal fuse rating on main PCB 2A 2A
Gas supply (governed metre only) I2H G20 natural gas I2H G20 natural gas
Inlet gas working pressure 20mbar 20mbar
Burner % CO2 case on 9.3 nominal 9.3 nominal
Burner % CO2 case off 9.3 nominal 9.3 nominal
1.93 m3/h 2.59 m3/h
68.1 ft3/h 91.5 ft3/h
1.02 m3/h 1.02 m3/h
35.9 ft3/h 35.9 ft3/h
Flue type C13, C33, C53 C13, C33, C53
NOx Class 5 Class 5
Heat output condensing mode 18.8kW 24.9kW
Heat input Nett Q = kW DHW max. 25.5 min. 9.6 DHW max. 30.8 min. 9.6
CH max. 18.3 min. 9.6 CH max. 24.5 min. 9.6
Heat output P = kW DHW max. 25.1 min. 9.5 DHW max. 30.0 min. 9.5
CH max. 18.0 min. 9.5 CH max. 24.0 min. 9.5
Approximate max. gas rate
after 10 mins. from cold
Approximate min. gas rate
after 10 mins. from cold

9
1.4 Gas Supply
The gas installation must be in accordance with the relevant
standards.
In GB this is BS6891.
In IE this is the current edition of I.S.813 “Domestic Gas
Installations”.
The supply from the governed meter must be of adequate size
to provide a steady inlet working pressure of 20mbar (8in wg)
at the boiler.
On completion, test the gas installation for soundness using the
pressure drop method and suitable leak detection fluid, purge
in accordance with the above standard.
1.5 Condensate Drain
A plastic drain pipe must be fitted to allow discharge of
condensate to a drain.
Condensate should, if possible, be discharged into the internal
household draining system. If this is not practical, discharge
can be made externally into the household drainage system or
a purpose designed soak away, see section 8 for more details.
1.6 Upward Piping Kit
Should any combination of the domestic hot water, heating flow
or return pipes come from above the boiler, an Upward Piping
Kit is available to facilitate, part No. A2041500.
Contact Glow-worm for further details.
1 Technical Information
13089
Diagram 1.2

10
600
55
150 5
55
150
+
+
This can be reduced to 20mm for a direct rear flu
e
A removable compartment door can be placed
a minimum of 5mm
2 Boiler Location and Ventilation
2.1 Location
This boiler is not suitable for outdoor installation.
This boiler may be installed in any room, although particular
attention is drawn to the installation of a boiler in a room
containing a bath or shower where reference must be made to
the relevant requirements.
This boiler is suitable for installation in bathroom zones 2 and
3.
In GB this is the current I.E.E. WIRING REGULATIONS and
BUILDING REGULATIONS.
In IE reference should be made to the current edition of I.S.813
“Domestic Gas Installations” and the current ETCI rules.
2.2 Clearances
The boiler should be positioned so that at least the minimum
operational and servicing clearances are provided, see diagram
2.1.
Additional clearances may be beneficial around the boiler for
installation and servicing.
For flue installations where external access is not practicable,
consideration should be given for the space required to insert
the flue internally, which may necessitate clearance larger than
those specified in diagram 2.1.
2.3 Timber Frame Buildings
If the boiler is to be installed in a timber frame building it should
be fitted in accordance with the Institute of Gas Engineers
document IGE/UP/7/1998. If in doubt seek advice from local
gas undertaking or Glow-worm.
2.4 Room Ventilation
The boiler is room sealed so a permanent air vent is not
required.
2.5 Cupboard or Compartment Ventilation
Due to the high efficiency and hence low casing temperature
of this boiler, cupboard or compartment ventilation is not
necessary.
Leave existing air vents.
13127
Diagram 2.1

11
3 Flue Options and Terminal Clearances
Top horizontal telescopic flue Ø60/100
Part No. A2043600
Top horizontal standard flue Ø60/100
Part No. A2043400
Rear telescopic flue Ø60/100
Part No. A2043500
Vertical Flue
Vertical Flue Adapter, concentric flue Ø60/100
Part. No. A2024600
Vertical flue terminal kit, concentric flue Ø60/100
Part. No. 2000460480
Twin Flue
Twin Flue Adapter, concentric flue Ø80
Part No. A2011000
Flue Accessories
Black Horizontal Terminal Kit, for use with
A2043500; A2043600; A2043400
Black Horizontal Terminal Kit,
concentric flue Ø60/100 - Part No. A2043700
Plume Management Kit, for use with
A2043500; A2043600; A2043400
Plume Management Kit, basic set, white,
concentric flue Ø60/100 - Part No. A2044100
1m extension, white - Part No. A2044300
87o elbow, white - Part No. A2044700
45o bend (2), white - Part No. A2044500
Plume Management Kit, basic set, black,
concentric flue Ø60/100 - Part No. A2044000
1m extension, black - Part No. A2044200
87o elbow, black - Part No. A2044600
45o bend (2), black - Part No. A2044400
Concentric Flue Ø60/100 accessories:
2 metre extension kit, concentric flue
Ø60/100 - Part No. 2000460483
1 metre extension kit, concentric flue
Ø60/100 - Part No. 2000460482
0.5 metre extension kit, concentric flue
Ø60/100 - Part No. 2000460481
Adjustable flue pipe 0-50mm kit,
concentric flue Ø60/100 - Part No. 2000460487
90o flue elbow pack,
concentric flue Ø60/100 - Part No. 2000460484
45o flue bend pack,
concentric flue Ø60/100 - Part No. 2000460485
Flue support clips (3),
concentric flue Ø60/100- Part No. A2043900
Additional accessories are available.
See Glow-worm “Flexicom Range Guide” for
configurations available.
Diagram 3.1

12
HORIZONTAL FLUES
A DIRECTLY BELOW AN OPENING, AIR BRICK,
OPENING WINDOWS 300
B ABOVE AN OPENING, AIR BRICK,
OPENING WINDOWS 300
C HORIZONTALLY TO AN OPENING,
AIR BRICK, OPENING WINDOWS 300
D BELOW GUTTER, DRAIN/SOIL PIPE 25
E BELOW EAVES 25
F BELOW A BALCONY OR CAR PORT 25
G FROM VERTICAL DRAIN PIPES AND
SOIL PIPES 25
H FROM INTERNAL/EXTERNAL CORNERS 25
H* TO A BOUNDARY ALONGSIDE THE
TERMINAL 300
I ABOVE ADJACENT GROUND OR
BALCONY LEVEL 300
J* FROM SURFACE OR A BOUNDARY
FACING THE TERMINAL 600
K FACING TERMINALS 1200
L FROM OPENING (DOOR/WINDOW)
IN CAR PORT INTO DWELLING 1200
M VERTICAL FROM A TERMINAL 1500
N HORIZONTALLY FROM A TERMINAL 300
VERTICAL FLUES
P FROM ANOTHER TERMINAL 600
Q ABOVE ROOF LEVEL 300
R FROM ADJACENT OPENING WINDOW 1000
S FROM ADJACENT WALL TO FLUE 300
Diagram 3.2
3.1 Flue Options
There are various flue options to choose from as illustrated in
diagram 3.1. The flue lengths and installation are described in
section 9.
3.2 Flue Terminal Position
The minimum acceptable siting dimensions for the terminal
from obstructions, other terminals and ventilation openings are
shown in diagram 3.2. For Ireland the minimum distances for
flue terminal positioning must be those detailed in I.S.813 “Do-
mestic Gas Installations”.
The terminal must be exposed to the external air, allowing free
passage of air across it at all times.
Being a condensing boiler some pluming may occur from the
flue outlet. This should be taken into consideration when se-
lecting the position for the terminal.
NOTE: If necessary it is permitted to increase the terminal pro-
trusion through the outside wall to greater than the minimum di-
mension of 87mm but no more than 600mm, see diagram 1.1.
Carports or similar extensions of a roof only, or a roof and one
wall, require special consideration with respect to any open-
ings, doors, vents or windows under the roof. Care is required
to protect the roof if made of plastic sheeting. If the carport
comprises of a roof and two or more walls, seek advice from
the local gas supply company before installing the boiler.
H* and J* See diagram 3.2 . These dimensions comply with
the building regulations, but they may need to be increased to
avoid wall staining and nuisance from pluming depending on
site conditions.
Plume Management Kit: Part No.A2044100 (white) or
A2044000 (black) can be used to overcome many site issues.
3.3 Terminal Guard
A terminal guard is required if persons could come into contact
with the terminal or the terminal could be subject to damage.
If a terminal guard is required, it must be positioned to provide
minimum of 50mm clearance from any part of the terminal and
be central over the terminal.
The guard should be similar to that shown in diagram 3.3.
A suitable guard is manufactured by: -
Tower Flue Components
Morley Rd.
Tonbridge
Kent
TN9 1RA.
Size: 280mm x 280mm x 270mm.
3 Flue Options and Terminal Clearances
Diagram 3.3
12325

13
4 Heating System
4.1 General
The boiler is for use only with sealed central heating systems.
The safety valve is an integral part of the boiler and it cannot
be adjusted.
The digital readout on the controls fascia indicates the system
pressure when there is no demand.
The circulation pump is integral with the boiler.
4.2 Expansion Vessel
The boiler has an integral expansion vessel with a capacity of
8 litres (1.76 gallons), with a charge pressure of 0.5bar.
NOTE: The expansion vessel volume depends on the total
water system volume and the initial system design pressure.
Guidance on vessel sizing is also given in the current issue of
BS5449 and BS7074 Part 1, for IE refer to the current edition
of I.S.813 “Domestic Gas Installations”.
4.3 Flow Rate
If it is necessary to alter the flow rate, the system can be
fitted with a lockable balancing valve in the main flow or
return pipes shown as valve “A” in diagram 4.1. The flow rate
through the boiler must not be allowed to fall below that given
in diagram 1.2.
4.4 Bypass
The boiler is fitted with an automatic bypass.
Diagram 4.2 shows the pump head remaining for the heating
system depending on the bypass setting and the speed
setting of the pump, see section 11 Commisioning.
Ensure that under no circumstances does the flow rate drop
below the figure specified, refer to diagram 1.2 and section
11.6.
The installation of the boiler must comply with the
requirements of the current issue of BS6798, in Ireland,
refer also to the current edition of I.S.813 “Domestic Gas
Installations”.
In GB it is necessary to comply with the Water Supply (Water
Fittings) Regulations 1999 (for Scotland, the Water Byelaws
2000, Scotland).
To comply with the Water regulations your attention is drawn
to: The Water Regulations guide published by the Water
Regulations Advisory Service (WRAS) gives full details of the
requirements.
In IE the requirements given in the current edition of I.S.813
“Domestic Gas Installations” and the current Building
Regulations must be followed.
4.5 Filling the Sealed System
NOTE: The water pressure at the boiler must be at least
1.2bar to enable filling the boiler to a minimum pressure. The
boiler is supplied with a filling device, see diagrams 4.1 and
4.3.
This filling device is designed to enable the filling and
pressurisation of the system in the event of loss of pressure.
Diagram 4.1
12800

14
4.6 Water Treatment
In the case of an existing system, it is ESSENTIAL that prior
to installing the new boiler the system is thoroughly flushed.
For optimum performance after installation of a new system,
the boiler and its associated central heating system should
also be flushed. Flushing should be carried out in accordance
with BS7593: 1992 using a cleanser such as Sentinel X300
or X400, Fernox Restorer or Salamander corrosion guard
cleaner.
For long-term corrosion protection, after flushing, a suitable
inhibitor should be used, refer to the current issue of BS
5449 and BS 7593 on the use of inhibitors in central heating
systems. Examples are Sentinel X100 Fernox Protector or
Salamander corrosion guard inhibitor.
4.7 Draining Points
Draining taps must be provided at the lowest points of the
system, which will allow the entire system to be drained.
Drain points for the appliance are provided at the positions
shown in diagram 4.3.
DRAIN POINTS
FILLING LOOP
Diagram 4.3
12657
4 Heating System
automatic bypass - fully open
automatic bypass - factory setting
automatic bypass - fully closed
pump speed 2pump speed 1
Remaining Conveyancing Capacity (mH2O)
0
1
2
3
4
0.5
1.5
2.5
3.5
4.5
5
900700500300100-100 150013001100
Litres/hr
Diagram 4.2
13102

15
5 Domestic Hot Water System
General - All domestic hot water circuits, connections, fittings
must be in accordance with the relevant standards and water
supply regulations.
For GB: Guidance G17 to G24 and recommendation R17 to
R24 of the Water Regulations Guide.
For IE: The current edition of I.S.813 “Domestic Gas
Installations”.
5.1 Water Pressure
The maximum working pressure of the domestic hot water
circuit is 10 bar. If the cold water supply pressure exceeds
this, then a pressure-reducing valve must be fitted in the
supply to the boiler.
6.1 Appliance Pack
IMPORTANT: With regards to the Health and Safety Manual
Handling requirements, two persons shall be required to lift
the appliance, refer to section 16 Manual Handling.
Please check the contents of packs as shown in diagram 6.1.
NOTE: The packs are located in the top polystyrene packing.
The wall hanging bracket is located at the rear of the boiler,
slide upwards to remove.
6.2 Wall Template
Take the wall template from the document pack located within
the top polystyrene packing and place in the desired position
on a flat wall, giving due consideration to the required boiler
clearances, see section 2, and the flue you are fitting.
6.3 Flue Hole Cutting
External access flue installation can use a 105mm diameter
core drill.
Internal access only flue installation will need a 125mm diam-
eter core drill.
If flue extension pipes are to be used then a core drill size
of 125mm is required. This will allow the extension pieces to
slope at 44mm/metre (2.5°) towards the boiler.
5.2 ‘Hard’ Water Areas
The temperatures within the heat exchanger are limited by
the boiler control system to minimise scale formation within
the hot water pipework. However, in areas where the water is
‘hard’ (i.e. more than 200mg/litre), it is recommended that the
hot water setting is reduced and that a scale reducer is fitted.
Refer to the manufacturer’s instructions or consult the local
water company for additional advice.
5.3 Domestic Water Flow Rate
The water flow rate is restricted to a maximum 9.4 l/min for
24cx and 11.7 l/min for 30cx, by a restrictor factory fitted
within the boiler.
6 Installation Preparation
Top horizontal flue - (standard and
telescopic)
The standard horizontal flue is designed with an internal fall of
44mm/metre (2.5°) towards the boiler for disposal of con-
densate therefore the hole can be drilled horizontally. If the
standard flue length alone is being used then the flue hole of
diameter 105mm can be cut in the position marked on the wall
template.
For standard side flues the horizontal flue centre line on the
wall template should be extended to the side wall, and the
vertical centre of the flue hole marked at 176mm from the
back wall.
For extended side flues, the flue hole centre should be
determined by extending the dashed inclined line on the
template to the side wall. This dashed line is drawn at 44mm/
metre (2.5°) rise from the boiler. Where this line reaches the
side wall, a horizontal line should be marked. The vertical
centre line of the flue should then be marked at 176mm from
the back wall.
To allow for the flue passing through the wall at this angle
a 125mm hole should be drilled irrespective of internal or
external installation.
Remove the wall template whilst drilling the flue hole.
6.4 Rear flue - telescopic
The rear flue is designed with an internal fall of 44mm/metre
towards the boiler for disposal of condensate therefore the
hole can be drilled horizontally. For installations with external
access, a 105mm diameter core drill can be used.

16
6 Installation Preparation
Diagram 6.1
12778
Central Heating x 2
Domestic Water flow
Gas
Domestic Water return
Safety Discharge Valve

17
Diagram 6.2
Diagram 6.3
13025
JIG SUPPORT
PLATE FIXINGS
6 Installation Preparation
6.5 Wall Hanging Bracket Assembly
The Wall Hanging Bracket is supplied in the main boiler
packaging at the rear of the boiler.
Reposition the wall template over the flue hole and mark
the position of the fixing holes for the hanging bracket, see
diagram 6.2.
NOTE: Due to the varied site conditions we do not supply
fixings and advise that the installer should supply those which
are suitable.
Drill fixing holes and insert suitable wall plugs.
Rear Flue only - If external access is not available the flue
to be used should be assembled as described in section 9
and inserted through the hole in the wall before fitting the wall
hanging bracket.
Fit the fixing jig support plate to the bottom of the wall hanging
bracket, push down to locate.
Mark, drill and plug at fixing points and secure the jig support
plate, see diagram 6.3.
Rear Flue only - The flue can now be pulled back through the
hanging bracket and secured as shown in diagram 6.2.
HANGING
BRACKET
FIXINGS
13024

18
JIG PLATE
JIG SUPPORT
PLATE
JIG SUPPORT
PLATE
Discard
JIG PLATE
UNION
CONNECTIONS
LOCATION
SLOTS
DOUBLE CHECK
INLET VALVE
'O' RING SEAL
WIRE
RETAINING
CLIP
ISOLATION VALVE
HANDLE
AND SCREW
7 Gas / Water & Appliance Connection
7.1 Systems Connection
The Gas and Water systems can be connected and filled prior
to installation of boiler.
All water and gas connections are on the fixing jig with the
exception of the condense drain and safety discharge, the
positions of these are shown on the wall template.
An Upward Piping Kit, part no. A2041500 should be used if
the supplies come from above the boiler otherwise the pipes
will have to be chased into the wall.
Assemble the pipes to the jig as shown in diagram 7.1.
Fit ‘O’ ring seal to the Double Check Valve assembly.
Fit Double Check Valve into Isolation Valve and secure with
the wire retaining clip.
Fit the Central Heating Isolation Valve handles and secure
with screws provided.
Fit the assembled Jig Plate to the Support Plate as shown in
diagram 7.2.
Assemble the Gas Service Cock and position onto the plastic
plug.
NOTE: Make sure the drain points are accessible, refer
diagram 4.3.
Plumb system pipe work to the copper tails. Do not subject
service cocks to heat.
There are flats on the body of the valves for locating a
spanner to aid tightening to copper tails using the tightening
sequence shown in diagram 7.4.
NOTE: At this stage alternative filling and pre-filling methods
can be used, refer to section 11 Commissioning.
Prior to filling the water system ensure that the blanking plugs
and isolation valves are secured.
Flush out the domestic hot water and the heating systems.
The whole of the gas installation, including the meter, should
be inspected, tested for soundness and purged in accordance
with the current issue of BS6891 and in IE the current edition
of I.S.813 “Domestic Gas Installations”.
12957
Diagram 7.2
Diagram 7.1
13101

19
Diagram 7.4
A - Central Heating Isolation Valve
B - Domestic Hot Water
C - Gas Service Cock
D - Domestic Cold Water
E - Washers (not shown)
F - Condensate Connection
G - Double check inlet valve
H - Safety Discharge Valve
7 Gas / Water & Appliance Connection
Diagram 7.3
12777
7.2 Appliance Connection
IMPORTANT: With regards to the Manual Handling
Operations, 1992 Regulations, the following lift operation
exceeds the recommended weight for a one man lift, refer to
section 16 Manual Handling.
Rear Flue only
This must be fitted before hanging the boiler, refer to Section 9.
NOTE: The appliance and jig (pre-filled) may contain a small
amount of water, place a water container beneath the boiler
connections.
Make sure the isolation valves are closed before disconnecting
the blanking plugs and discarding the jig plate.
Position the sealing washers supplied in the Loose Items pack,
as shown in diagram 6.1.
Lifting the boiler into position, lean the top of the boiler slightly
to the wall and position just above the hanging bracket. Lower
the boiler slowly push back and engage onto the hanging
bracket making sure the boiler is located over the retaining
bosses, see diagram 7.3.
Remove the protective caps.
Engage the fixing jig connections, ensuring that the previously
positioned washers have not been disturbed.
Make good the final connections.
Numbers 1 - 5
show the sequence to be used
when tightening to copper tails.
12955
A
B
CDA
34
2
15
F
GH

20
SAFETY
DISCHARGE
VALVE
SECURING
CLIP
UNION NUT
AND SEAL
VIEW ON UNDERSIDE OF BOILER
8 Safety Discharge Valve & Condensate Connections
Diagram 8.1
12667
8.1 Safety Discharge Valve
The pipe from the safety discharge valve must not discharge
above an entrance, window or any type of public access area.
Take the safety discharge pipe, supplied in the pipe pack and
the union nut and seal, supplied in the loose items pack and
fit as shown in diagram 8.1.
This must be extended, using not less than 15mm o.d. pipe,
to discharge, in a visible position, outside the building, facing
downwards, preferably over a drain.
The pipe must have a continuous fall and be routed to a
position so that any discharge of water, possibly boiling,
or steam cannot create any danger to persons, damage to
property or external electrical components and wiring.
To ease future servicing it is advisable to use a compression
type fitting to extend the safety discharge valve tube.
8.2 Condensate Drain Connection
The condensate drain connection is at the rear of the boiler,
see diagram 7.4. A flexible condensate outlet pipe is supplied
loose in the base polystyrene packaging and should be used
to fit onto the drain connection, to discharge condensate to
a drain. The drain pipe 22mm to 25mm OD. non corrosive
plastic pipe should have a fall of at least 2.50 away from the
boiler.
Condensate should, if possible be discharged into the
household internal drainage system. If this is not practicable,
discharge can be allowed into the external household drains
or a purpose designed soak away, refer to diagram 8.2.
It is recommended that any external condensate drain pipe is
insulated and also preferably of 32mm diameter, to prevent
freezing in adverse weather conditions.
The condensate is discharged periodically in ‘slugs’ by
siphonic action.
It is not necessary to provide air breaks or extra traps in the
discharge pipe as there is already a trap inside the boiler.
Fitting an extra trap may cause the boiler siphon to work
incorrectly.
Refer to BS5546 or BS6798 for advice on disposal of boiler
condensate.