Glowworm Xtramax HE User manual

www.glow-worm.co.uk
Xtramax HE
G.C. No. 47-047-29
Installation and Servicing
www.glow-worm.co.uk
High Effi ciency
Condensing
Boilers

2
Guarantee Registration
Benchmark places responsibilities on both manufacturers and installers. The purpose is to ensure that customers are provided
with the correct equipment for their needs, that it is installed, commissioned and serviced in accordance with the manufacturer’s
instructions by competent persons and that it meets the requirements of the appropriate Building Regulations. The Benchmark
Checklist can be used to demonstrate compliance with Building Regulations and should be provided to the customer for future
reference.
Installers are required to carry out installation, commissioning and servicing work in accordance with the Benchmark Code of
Practice which is available from the Heating and Hotwater Industry Council who manage and promote the Scheme.
Visit www.centralheating.co.uk for more information.
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 and 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
competent person approved at the time by the Health and Safety Executive,
in accordance with the manufacturer’s recommendations. We strongly recommend regular
servicing of your gas appliance, but where the condition is not met, any chargeable spare parts or
components issued within the applicable guarantee period still benet 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.
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
Important Information 4
Statutory Requirements 5
Boiler Design 6
Safety Devices 6
Servicing, Maintenance and Spare Parts 6
Technical Information 1 7
Boiler Location and Ventilation 2 10
Flue Location and Ventilation 3 11
Heating System 4 13
Domestic Hot Water System 5 13
Installation Preparation 6 14
Gas/Water and Appliance Connection 7 15
Safety Discharge, Condensate and
Tundish Connection 8 16
Electrical Connection 9 20
Commissioning 10 21
Servicing 11 26
Fault Finding 12 33
Replacement Parts 13 36
Spare Parts 14 43
Manual Handling 15 45
Declaration of Conformity 16 46
INTRODUCTION
INSTALLATION
INSTRUCTIONS
MAINTENANCE
These instructions consist of, Installation, Servicing, Fault Finding, Replacement of Parts
and Spares. The instructions 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
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.
Gas Category
This boiler is for use only on G20 natural gas, but may be
converted for use on G31 gas (propane L.P.G.).
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 approved
at the time by the Health and Safety Executive in accordance
with the current issue of these regulations.
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 hazardous
to health.
The adhesives and sealants used in this appliance are cured
and give no known hazard in this state.
Manual Handling
With regards to the “Manual Handling Operations, 1992
Regulations”, the appliance exceeds the recommended weight
for a one man lift, refer to section 16 for more information.
The handling of the boiler may involve lifting, pushing and pulling,
the use of a sack truck may be required.
The following handling techniques and precautions should be
considered:
- Grip the boiler at its base
- Be physically capable
- Use safety clothing where appropriate, e.g. gloves, safety
footwear.
Ensure safe lifting techniques are used
- Keep back straight.
- Avoid twisting at the waist.
- Avoid upper body/top heavy bending.
- Always grip using the palm of the hand.
- Use designated hand holds.
- Keep load as close to body as possible.
- Always use assistance if required.
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 ETCI rules.
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 identied 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 containing a
bath or shower.
Wiring to the boiler must be PVC 85OC insulated cable, not less
than 0.75mm2 (24/0.20mm).
Testing and Certication
This boiler is tested and certicated for safety and performance.
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
certication, boiler warranty and may also infringe the current
issue of the statutory requirements.
Important Information

5
CE Mark
This boiler meets the requirements of Statutory Instrument,
No. 3083 The Boiler (Efciency) Regulations, and therefore is
deemed to meet the requirements of Directive 92/42/EEC on
the efciency requirements for new hot water boilers red with
liquid or gaseous fuels.
Type test for purposes of Regulation 5 certied by: Notied
body 0087.
Product/production certied by: Notied body 0049 or 1312.
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.
IMPORTANT
Where no British Standards exists, materials and equipment
should be t for their purpose and of suitable quality and
workmanship.
The installation of this boiler must be carried out by a competent
person approved at the time by the Health and Safety Executive
in accordance the rules in force in the countries of destination.
Manufacturer’s instructions must not be taken as overriding
statutory requirements.
Statutory Requirements
In GB, the installation of the boiler must comply with the
requirements of the current issue of BS6798 and be carried out
by a competent person, approved at the time by the Health
and Safety Executive, 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 specic 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, approved at the time by the Health and Safety Executive,
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.
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.
IE: I.S.813, BS5546, BS 5449, BS 7074, BS 7593.
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 specication (CheSS)
and
2) Controls for domestic central heating system and hot water.
BRECSU.
Statutory Requirements
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 tightness using the
pressure drop method and suitable leak detection uid, purge
in accordance with the above standard.
Domestic Hot Water
All domestic hot water circuits, connections, ttings must be
in accordance with the relevant standards and water supply
regulations.
GB: Guidance G17 to G24 and recommendation R17 to R24 of
the Water Regulations Guide.
IE: The current edition of I.S.813 “Domestic Gas Installations”.
Heating System
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.

6
Boiler Design
Boiler Design
This boiler is designed to provide central heating and
instantaneous hot water for use as part of a sealed water central
heating system with fully pumped circulation.
The pumps , expansion vessel and associated safety devices are
all tted within the boiler. The integral programmer is designed for
both simple operation and maximum control. Once the controls
are set the boiler will operate automatically.
Glow-worm has specially designed accessories for your appliance
depending on yourrequirements, please contact your supplier
or visit our website www.glow-worm.co.uk.
Condensate Drain
A plastic drain pipe must be tted 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 9 for more details
Pluming from ue terminal
Like all condensing boilers this appliance will produce a plume
of condensation from the ue terminal in cool weather. This is
due to the high efciency and hence low ue gas temperature
of the boiler.
This is normal and not an indication of a fault.
Maintenance and Servicing
To ensure the continued efcient 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 approved at the time by the Health and Safety Executive
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 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 specication 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.
Servicing, Maintenance and Spare Parts
Electrical Supply Failure Reset Switch
In the event of a power supply failure the boiler will not work.
Normal operation of the boiler should resume when the electrical
supply is restored.
However, if the boiler does not resume normal operation turn
the mains reset switch off and on. If the boiler does not resume
normal operation after this operation the overheat stat may have
operated.
Overheating safety
In the event of the boiler overheating the safety devices will
cause a safety shutdown. If this happens, call your Installation/
Servicing company.
Discharge and Relief Valves
Heating and Domestic discharge safety valves and a
Domestic hot water pressure relief valve are tted to this
appliance. The valves must not be touched except by a
competant person.
If the valves discharges at any time, switch the appliance off
and isolate it from the electrical supply.
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 protection
device will operate the pump when the temperature of the boiler
water falls below 7°C.
The burner will re if the temperature inside the boiler falls to 3°C.
When the temperature reaches 10°C the boiler stops.
Any other exposed areas of the system should be protected by
a separate frost thermostat.
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.
Safety Devices

7
1.1 Technical Data
All dimensions are given in millimetres (except as noted).
See diagrams 1.1, Table 1, Table 1 continued and Table 2.
700
890
301
480
12907
Diagram 1.1
1 Technical Information
Description Unit Xtramax HE
Gas category ll2H3P
SEDBUK rating 90.6% Band A
Boiler flue type C13, C33, C53
Heating
Heating output at 80°C/60°C (P) kW 7.6 - 28
Efficiency calculated on net calorific value at 80/60°C % 95.8 - 97.8
Heating output at 50°C/30°C (P) kW 8.6 - 30.6
Efficiency calculated on net calorific value at 50/30°C % 107
Minimum calorific flow rate (Q min) kW 8
Maximum calorific flow rate (Q max) kW 28.6
Heating minimum flow rate l/h 500
Maximum heating temperature C° 80
Minimum heating temperature C° 22
Expansion vessel, useful capacity l 12
Expansion tank initial pressure bar 0.75
Maximum system capacity at 75°C l 240
Safety valve, maximum service pressure (PMS) bar 3
Domestic hot water
Heating output (P) kW 7.6 - 33.2
Minimum calorific flow rate (Q min) kW 8
Maximum calorific flow rate (Q max) kW 34.2
Minimum hot water temperature °C 38
Maximum hot water temperature °C 63
TABLE 1

8
1 Technical Information
Combustion
Fresh air flow rate (1013 mbar - 0°C) m3/h 43
Product outlet flow rate g/s 15.3
Product outlet temperature °C 68
Values of product outlet (measured on nominal heating output with G20 reference gas):
CO ppm 86
mg/kWh 92
CO2 % 9.2
NOx balance ppm 21.1
mg/kWh 37.3
Dimensions:
Height mm 890
Width mm 700
Depth mm 480
Net weight kg 75
Weight of appliance when full kg 120
Supply voltage V/Hz 230/50
Maximum absorbed power W 241
Electrical rating A 1.05
Fuse mA 630
Electric protection IPX4D
Class 1
CE number 1312 BP 4108
Technical data depending on the gas type Unit Xtramax HE
Natural gas G 20 (1)
Sanitary flow rate at maximum input m3/h 3.62
Heating flow rate at maximum input m3/h 3.02
Flow rate at minimum input m3/h 0.68
Inlet pressure mbar 20
Burner injector diameter mm 5.65
(1) 15 °C, 1013,25 mbar
TABLE 1 (continued)
TABLE 2
Specific flow rate (D) (ΔT 30°C) l/min 21
Threshold flow rate l/min 0
DHW storage vessel l 42
DHW storage vessel heat up time min 6
Time to reheat 70% of the storage to 60°C min 4
Maximum supply pressure bar 16
Temp./pressure relief valve operating pressure bar 10
Temp./pressure relief valve operating temperature °C 90
Cold water flow rate regulator l/min 16
Safety valve, maximum service pressure bar 8
Minimum operating pressure bar 0.7
Maximum operating pressure bar 10

9
D2
D1
1 Technical Information
1 Flue outlet
2 Main heat exchanger
3 Burner
4 Ignition and control electrode
5 Fan
6 Gas control valve
7 DHW storage vessel
8 Condensate drain
9 Overheat safety thermostat
10 Temperature sensor for DHW storage vessel
11 Expansion vessel
12 Heating return thermistor
13 Heating ow thermistor
14 Ignition module
15 Heating Pump
16 Water pressure sensor
17 Domestic plate to plate heat exchanger
18 Three way valve
19 Domestic expansion vessel
20 Drain cock
21 Flow switch
22 Heating discharge safety valve
23 DHW temperature sensor
24 DHW discharge safety valve
25 Heating isolating valve
26 Filter on cold water inlet
27 Filling system
28 Filter on heating circuit
29 Heating isolating valve
30 Domestic cold water isolating valve
31 Heating isolating valve
32 Gas isolating valve
33 DHW pump
34 Storage anode protection
35 Non return valve
36 Temperature / pressure relief valve
37 Tapping (plug connection) for the recirculation loop
38 Pressure reducing valve and check valve
A Heating return
B Cold water inlet
C Heating ow
D Domestic hot water outlet
D1 Discharge from HTG safety valves
D2 Discharge from temp / press and expansion valve (to
tundish)
E Gas
F Cold water supply

10
2 Boiler Location
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.
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 benecial around the boiler for
installation and servicing.
For ue installations where external access is not practicable,
consideration should be given for the space required to insert
the ue internally, which may necessitate clearance larger than
those specied in diagram 2.1.
2.3 Timber Frame Buildings
If the boiler is to be installed in a timber frame building it should
be tted in accordance with the Institute of Gas Engineers
document IGE/UP/7/1998. If in doubt seek advice from the local
gas undertaking or Glow-worm.
2.4 Combustible Material
The boiler and ue are suitable for installation onto and through
combustible materials provided that:-
1) Minimum 5mm clearance is maintained around the
circumference of the ue (air intake).
2) The combustible surface and xings are suitable for supporting
the load.
3) The minimum clearances from the boiler case are
maintained.
2.5 Room Ventilation
The boiler is room sealed so a permanent air vent is not required.
2.6 Cupboard or Compartment Ventilation
If the boiler is tted into a compartment or cupboard it does not
require ventilation openings.
Do not use the compartment or cupboard for storage. Leave
existing air vents.
12911
+ A removable compartment door can be placed
at least 5mm in front of the appliance
5
5
600 +
200
50
5
150
Diagram 2.1

11
3.1 Flue Length
See diagrams 3.1 to 3.3 to determine which ue can be used.
When extension pipes are used the ue system must be designed
to have a continuous fall to the boiler of at least 2.5o to allow
condensate to run back into the boiler and out via the drain.
WARNING: Any duct that goes through a wall and whose
temperature is over 60°C from the room temperature will be
thermally insulated at this passage. The insulation will be
composed of an appropriate insulating material whose thickness
is ≥ 10 mm and thermal conductibility ≤ 0.04 W/m.K.
Horizontal Concentric Flue - The maximum permissable
horizontal ue length is 5 metres plus 1 90o
elbow, see diagram 3.1
(dimension L). This can be achieved by the use of the concentric
ue accessories, however, for every 90o or 45o elbows used the
ue length MUST be reduced by 1 metre.
The ue can be installed from inside the building, when access
to the outside wall face is not practicable.
Vertical Concentric Flue - The maximum permissable vertical
ue length is 5.5 metres plus 1 90o elbow,. This can be achieved
by the use of The concentric ue accessories, however, for
every 90o or 45o elbows used the ue length MUST be reduced
by 1 metre.
Twin Flue - The maximum permissable ue length is 40 metres
inclusive of 2 90o elbows the separator and the combined duct
lengths L1 and L2, however, for every 90o or 45o elbows used
the ue length MUST be reduced by 1 metre.
3.2 Flue Accessories
Additional accessories are available.
See Glow-worm “Flue Options Guide” for congurations available.
Diagram 3.1
Diagram 3.2
Horizontal concentric ue
Vertical
concentric ue
1
L
72
GASKET
3 Flue Location and Ventilation
Diagram 3.3
Twin ue
L1
L2
L1
188
L

12
3 Flue Location and Ventilation
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 3.4
Diagram 3.5
3.3 Terminal Position
The minimum acceptable siting dimensions for the terminal
from obstructions, other terminals and ventilation openings are
shown in diagram 3.4. For Ireland the minimum distances for ue
terminal positioning must be those detailed in I.S.813 “Domestic
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 ue
outlet. This should be taken into consideration when selecting
the position for the terminal.
Carports or similar extensions of a roof only, or a roof and one
wall, require special consideration with respect to any openings,
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 3.4 . 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.
Increased siting exibility can be achieved by using the Glow-worm
Plume Management Kit. A2044000 (black) or A2044100 (white).
NOTE: If the ue terminal is positioned near a light source
insects may enter the ue system. Where safe and practical to
do so advise the homeowner to check the ue outlet and clear
visible insects from the terminal end.
3.4 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 3.5.
A suitable guard is manufactured by: -
Tower Flue Components
Morley Rd.
Tonbridge
Kent
TN9 1RA.
Size: 280mm x 165mm. Part No. CGDK3

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 pumps are integral with the boiler.
4.2 Expansion Vessel
The boiler has an integral expansion vessel with a useful capacity
of 12 litres (2.6 gallons), with a charge pressure of 0.75bar.
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 ow rate, the system can be tted
with a lockable balancing valve in the main ow or return pipes.
The ow rate through the boiler must not be allowed to fall below
500 litres/hr.
4.4 Bypass
The boiler is tted with an automatic bypass. Ensure that under no
circumstances does the ow rate drop below the gure specied.
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 lling the boiler to a minimum pressure. The boiler is
supplied with a lling device.
This lling device is designed to enable the lling and pressurisation
of the system in the event of loss of pressure.
4.6 Water Treatment
In the case of an existing installation, it is ESSENTIAL that prior
to installing the new boiler the system is thoroughly ushed. For
optimum performance after installation of a new system, the
boiler and its associated central heating system should also
be ushed. Flushing should be carried out in accordance with
BS7593: 1992 using a cleanser such as Sentinel X300 or X400,
Fernox cleanser or Salamander corrosion guard cleaner.
For long-term corrosion protection, after ushing, an inhibitor
suitable for aluminium heat exchangers 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
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.
A drain point for the appliance is provided as an integral part of
the hydroblock.
General - All domestic hot water circuits, connections, ttings
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 circuit should be designed to avoid any unnecessary ow
losses (decrease the number of elbows).
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 tted in the supply to the boiler.
The boiler will operate with a minimum supply pressure but
with a low ow. Optimum performance will be achieved with a
pressure of 1 bar.
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 a scale
reducer is tted.
Refer to the manufacturer’s instructions or consult the local water
company for additional advice.
5.3 Domestic Water Flow Rate
The water ow rate is restricted to a maximum 16 l/min by a
restrictor tted during boiler installation,.
5 Domestic Hot Water System

14
6 Installation Preparation
6.1 Appliance Pack
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 Manual Handling
section15.
Please check the contents of packs.
The boiler carton includes the document pack and parts pack.
Items within the document pack include:
• 1User manual
• 1 Installation manual
• 1 Guarantee envelope
• 1 Wiring diagram
• 1 Gasket pack
Items within the parts pack include:
• 1 Connection pack 1
• 1 Connection pack 2 plus wall template
• 1 Guarantee envelope
• 1 Safety valve drain pack
The ue is supplied separately.
6.2 Wall Template
Take the wall template from connection pack 2 and place in the
desired position on a at wall, giving due consideration to boiler
clearances, see diagram 2.1, and the ue you are tting.
6.3 Flue Hole Cutting
The standard horizontal concentric ue is designed with an
internal fall of 35mm/metre towards the boiler for disposal of
condensate. If the standard ue length alone is being used
then the ue hole of diameter 105mm can be cut in the position
marked on the wall template.
Remove the wall template whilst drilling the ue hole.
6.4 Hanging Bracket
Reposition the wall template over the ue hole and mark the
position of the xing holes for the hanging bracket, see diagram
6.1.
The hanging bracket will be adapted to the features of the bearing
wall and will have to take into account the weight of the boiler
lled with water.
Drill the holes for the xing screws in accordance to the diagram
below and to the size of the wall template delivered with the
appliance.
Insert suitable wall plugs.
Screws mechanical features will match, at least, the values
indicated, see diagram 6.1.
6.5 Appliance Connection
Remove front panel, unscrew and remove the two retaining
screws from the bottom of the front panel.
Remove front panel by lifting up and forward.
Remove the self adhesive wiring diagram label from the document
envelope, t the self adhesive wiring diagram label to the inside of
the front panel, put front panel in a safe place to avoid damaging it.
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 Manual Handling
section15.
Place the boiler above the hanging bracket.
Slowly lower the boiler.
Set the seals on the different pipe ttings.
Make connections to boiler, gas, water and heating cocks with
the tube assemblies supplied in piping pack.
Do not forget to connect the lling loop extension on the lling tap.
45 250 165 85 45
Ø105
104.5 50
min.
Diagram 6.1

15
7 Gas / Water and Appliance Connection
7.1 Gas Connection
Before connection check supply of local gas.
Refer also to statutory requirements.
Do not subject the gas service cock to heat.
The whole of the gas installation, including the meter, should
be inspected, tested for tightness and purged in accordance
with the current issue of BS6891 and in IE the current edition
of I.S.813 “Domestic Gas Installations”.
230
256
4
3
2
1
5
6
7
8
9
10
11 3
12 8
5
A
5
13 6614
15
16
17
18
7.2 Water & Appliance Connections
Before undertaking any operation, carefully clean the pipes
with an appropriate product in order to remove impurities such
as lings, welds, oils and greases that may be present.
These foreign bodies may enter the boiler and disrupt the
operation.
Do not use any solvents that could damage the heating circuit.
Flush out the domestic hot water and the heating systems before
connecting to the boiler.
Take care when soldering pipes as the heat could damage the
seals and cause leakage.
Make the connections to the domestic hot water and heating
systems.
The heating return adapter is tted with a lter (11) that can be
reached by unscrewing the end nut.
This operation must be achieved once the heating return
shut-off taps are closed.
The test pressure will be read on a pressure gauge (9) (not
supplied) screwed in the position of the rst nut of the heating
return adapter.
Only use the genuine seals delivered with the appliance.
Check that there is no leakage.
KEY
Connection pack 1 :
A Pressure test point
1 Hanging bracket
2 Heating return pipe: angular
bush to weld Ø 22 + nut 3/4"
5 Gasket 3/4" (x3)
8 Cold water inlet + domestic hot
water outlet with isolating valve
12 Heating ow with isolating valve
13 Gas service cock
14 Gasket 1/2" (x3)
15 Gas pipe: angular bush to weld
Ø15 + nut 1/2"
16 Cold water inlet pipe + domestic
hot water pipe: angular bush to
weld Ø 15 + nut 1/2"
17 Heating ow pipe: angular bush
to weld Ø 22 + nut 3/4"
Connection pack 2 :
4 Heating return with isolating
valve
9 Nut / Pressure gauge connection
10 Gasket
11 Heating return lter
Gasket pack :
3 Cold water ow rate limiter
6 Gasket (x2)
7 Gasket (x3)
Diagram 7.1

16
Diagram 8.1
NOTE: The pipes from the heating and domestic hot water
safety discharge valves must not discharge above an en-
trance, window or any type of public access area.
8.1 DHW Safety Discharge Valve
Take the short safety discharge tube, union nut and seal,
supplied loose in the boiler ttings pack.
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 tting to extend the safety discharge valve tube.
WARNING: Cylinder relief valve connections should not be
used for any other purpose.
1
2
3
4
5
6
7 8 9 10
9
11
13
8
7
17
12
18
14
15
16
19
20
21
22
23
24
KEY
1 Domestic hot water safety valve
2 Drain cock
3 Filling loop extension knob
4 Gasket
5 Nut
6 Discharge valve for PRV (BLUE)
on domestic hot water circuit
7 Nut (x2)
8 Gasket (x2)
9 Gasket (x2)
10 Union coupling
11 Nut
12 Olive 15mm.
13 Tundish
14 Olive 22mm.
15 Nut
16 Nozzle
17 Nut
18 Inner tee
19 Nut
20 Olive 15mm.
21 Discharge pipe for PRV (RED) on
heating circuit
22 Gasket
23 Nozzle
24 Tube for drain valve
8 Safety Discharge, Condensate and Tundish Connections

17
8 Safety Discharge, Condensate and Tundish Connections
Valve outlet size Minimum size
of discharge to
tundish D1
Minimum size of
discharge pipe D2
from tundish
Maximum resistance
allowed expressed as
a length of straight pipe i.e.
no elbows or bends
Resistance
created by
each elbow
or bend
G 1/2” 15 mm 22 mm
28 mm
35 mm
up to 9 m
up to 18 m
up to 27 m
0.8 m
1.0 m
1.4 m
G 3/4” 22 mm 28 mm
35 mm
42 mm
1.0 m
1.4 m
1.7 m
G 1” 28 mm 35 mm
42 mm
54 mm
1.4 m
1.7 m
2.3 m
500 mm
max.
300 mm max.
1
3
2 4
KEY
1 Safety device eg. temperature relief valve
2 Tundish (supplied)
3 Trapped gully
4 Fixed grating
Discharge pipe D1: from temperature relief valve to tundish.
Discharge pipe D2: from tundish with continuous fall.
See table above for size examples.
21
D2
D1
KEY
1 Tundish (supplied)
2 Gully
D1 Discharge pipe
D2 Discharge pipe
Discharge pipe D1: from heating safety valve on jig.
Discharge pipe D2: from domestic hot water safety valve.
Diagram 8.3

18
1
2
Diagram 8.2
8 Safety Discharge, Condensate and Tundish Connections
8.3 Tundish discharge
The internal safety valves, 24 and 36 have been tee’d to-
gether and the discharge pipe run so that it exits at the right
hand bottom of the boiler ( Block diagram) 11.8.
The tundish (supplied) must be used with this outlet within the
normal guidelines and code of practice and must be installed
so that it is visible to the occupants and positioned away from
any electrical devices.
It is necessary, during installation, to connect a 22 mm diameter
metal discharge pipe to a suitable position outside the building.
It is permissible to use copper pipe.
WARNING: The discharge pipe from the tundish should terminate
in a safe place where there is no risk to persons in the vicinity
of the discharge, be of metal and:
Be at least one pipe size larger than the nominal outlet size of
the safety device unless its total equivalent hydraulic resistance
exceeds that of a straight pipe 9m long i.e. discharge pipes
between 9m and 18m equivalent resistance length should be
at least larger than the nominal outlet size of the safety device,
between 18m and 27m at least 3 sizes larger, and so on.
Bends must be taken in to account in calculating the ow
resistance.
Have a vertical section of pipe at least 300mm long, below the
tundish before any elbows or bends in the pipework.
Be installed with a continuous fall.
Be positioned away from any electrical appliances.
Have discharges visible at both the tundish and the nal point of
discharge but where this is not possible or practically difcult there
should be clear visibility at one or these of these locations.
Examples of acceptance discharge arrangements are:
Ideally below a xed grating and above the waterseal in a
trapped gully.
Downward discharges at a low level; i.e. up to 100mm above
external surfaces such as car parks, hard standing, grassed
areas etc. are acceptable providing that where children may
play or otherwise come in to contact with discharges, a wire
cage or similar guard is positioned to prevent contact, whilst
maintaining visibility.
Discharges at high level; e.g into metal hopper and metal
down pipe with the end of the discharge pipe clearly visible
(tundish visible or not) or into a roof capable of withstanding
high temperature discharges of water and 3m from any plastics
guttering systems that would collect such discharges (tundish
visible).
Where a single pipe serves a number of discharges, such as
in blocks of ats, the number served should be limited to not
more than 6 systems so that any installation can be traced
reasonably easily.
The single common discharge pipe should be least one pipe
size larger then the largest individual discharge pipe to be
connected.
If unvented hot water storage systems are installed where
discharges from safety devices may not be apparent i.e.
in dwellings occupied by blind, inrm or disabled people,
consideration should be given to the installation of an electronically
operated device to warn when discharge takes place.
NOTE: the discharge will consist of scalding water and steam.
Asphalt, roong felt and non-metallic rainwater goods may be
damaged by such discharges.
WARNING: This appliance must be earthed. Incorrect installation
can cause electric shock or appliance damage.
This appliance must be wired in accordance with these
instructions.
Any fault arising from incorrect wiring cannot be put right under
the terms of the Glow-worm guarantee.
All system components must be of an approved type.
Electrical components have been tested to meet the equivalent
requirements of the BEAB.
Do not interrupt the mains supply with a time switch or
programmer.
Connection of the whole electrical system and any heating
system controls to the electrical supply must be through a
common isolator.
Isolation should preferably be by a double pole switched fused spur
box having a minimum contact separation of 3mm on each pole.
The fused spur box should be readily accessible and preferably
adjacent to the boiler. It should be identied as to its use.
8.2 Condensate Drain Connection
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 diagram 8.4 for more details
Connect the exible pipe to the condensate drain exible
connection pipe supplied (1). Ensure there is a continual fall of
2.5° (44 mm/m).
(Do not use copper pipes).
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, see
diagram 8.2.
Fitting an extra trap may cause the boiler siphon to work incorrectly.
IMPORTANT NOTE:
The oat of the condensate trap also ensures fume tightness.
Therefore, it is not necessary to add water in the condensate trap.
Refer to BS5546 or BS6798 for advice on disposal of boiler
condensate.

19
8 Safety Discharge, Condensate and Tundish Connections
Diagram 8.4
13000

20
IMPORTANT NOTE
ALL electrical connections to the boiler
must be permanently xed to a wall or a
sturdy support feature in a tidy manner.
9 Electrical Connection
Diagram 9.1
CONTROL
PANEL
REAR COVER
SECURING
SCREW (3)
CABLE
EXIT
VOLTAGE FREE
HEATING
CONTROLS
CONNECTION
CONTROL
PANEL
REAR COVER
WIRE
LINK (E)
13950
WARNING: This appliance must be earthed.
● This appliance must be wired in accordance with these
instructions. Any fault arising from incorrect wiring cannot be
put right under the terms of the Glow-worm guarantee.
● All system components must be of an approved type.
Electrical components have been tested to meet the
equivalent requirements of the BEAB.
● Do not interrupt the mains supply with a time switch or
programmer.
● Connection of the whole electrical system and any heating
system controls to the electrical supply must be through a
common isolator.
● Isolation should preferably be by a double pole switched
fused spur box having a minimum contact separation of
3mm on each pole. The fused spur box should be readily
accessible and preferably adjacent to the boiler. It should be
identied as to its use.
● A fused three pin plug and shuttered socket outlet may be
used instead of a fused spur box provided that it is not used in
a room containing a xed bath or shower.
● The boiler is suitable for installation in bathroom zones 2
and 3.
9.1 Mains Supply Cable
The appliance mains supply cable should be permanently
connected to a cable anchorage. The cable anchorage shall
relieve conductors from strain, including twisting at the terminals
and should also protect the insulation of the conductors from
abrasion.
9.2 Electrical Connections - Testing
Carry out preliminary electrical system checks as below:
1. Test insulation resistance to earth of mains cables.
2. Test the earth continuity and short circuit of cables.
3. Test the polarity of the mains.
Please ensure the "Benchmark" logbook is completed and left
with the user and the magnetic lighting instruction label is placed
on the surface of the boiler casing.
9.3 Voltage Free System Controls
WARNING: UNDER NO CIRCUMSTANCES MUST ANY MAINS
VOLTAGE BE APPLIED TO ANY OF THE TERMINALS ON THE
VOLTAGE FREE HEATING CONTROLS CONNECTION PLUG.
This boiler will operate continuously on heating as supplied, if
the wire link (E), tted between the two terminals of the heating
controls connection, is left in place, see diagram 9.1.
System heating controls e.g. Room thermostat, should be tted
in accordance with the rules in force.