Glow-worm Flexicom 12hx, Flexicom 15hx, Flexicom 18hx, Flexicom 30hx, 35hx Installation And Servicing

1

Installation and Servicing

www.glow-worm.co.uk

Flexicom

18hx

High Efciency

Condensing

Boilers

G.C. No. 41-315-42

12786

15hx

G.C. No. 41-315-29

12hx

G.C. No. 41-315-28

24hx

G.C. No. 41-315-61

30hx

G.C. No. 41-315-67

35hx

G.C. No. 41-315-68

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 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 CORGI

registered gas installer,

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.

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

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.

CONTENTS DESCRIPTION SECTION PAGE

Warnings 4
Important Information 4
Statutory Requirements 5
Boiler Design 6
Safety Devices 6
Servicing, Maintenance and Spare Parts 6

Boiler Specication 1 7

Boiler Dimensions and
Hydraulic Schematic 2 8
Boiler Location, Clearances and
Ventilation 3 9
Flue Options and Terminal Clearances 4 10
Water Systems 5 12

• General 5 12

• Open Vented 5 13

• Sealed Systems 5 14
Installation Preparation 6 16
Boiler Fixing 7 17
Gas/Water and Appliance Connection 8 18
Condensate Connections 9 18
Flue Length Preparation and Installation 10 20
Electrical Connection 11 36
Commissioning 12 38

Servicing 13 40
Fault Finding 14 45
Replacement of Parts 15 51
Spare Parts 16 56
Manual Handling 17 57
Declaration of Conformity 18 58

INTRODUCTION

INSTALLATION

MAINTENANCE

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.

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
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 17 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 Glow­worm.
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 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.

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 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 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 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

These boilers are designed to provide central heating from
a fully pumped open vented or sealed water system and
domestic hot water using a fully indirect cylinder.
Once the controls are set the boiler operates automatically.

Range Rating

The boilers are fully modulating for central heating, and it is
therefore not necessary to range rate the boiler. However, if
desired, it is possible to range rate the boiler between 10 and
Max. output (according to the model), in 1kW increments,
refer to section 12.

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 or Glow-worm
service.

Overheating Safety

The boiler software is designed to recognise the potential for
an overheat lockout and will shutdown before this happens.
To restart the boiler, press the reset button on the controls
fascia.

If the boiler fails to resume normal operation and all external
controls are calling for heat, then call your Installation/
Servicing company or Glow-worm service.

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 protection 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
periodically. After 10 minutes the pump will be stopped if the
temperature 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.

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 8 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.

Servicing, Maintenance and Spare Parts

Servicing and Maintenance

To ensure the continued efcient and safe operation of the

boiler 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.

“Benchmark” scheme

Glow-worm support the Benchmark initiative. It is very important
that the Installation, Commissioning and Service Record is
completed by the installation engineer and handed over to the
user.

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 Glow­worm’s own service organisation using the telephone number
on the inside front cover of this booklet.

7

1 Boiler Specication

14730

Diagram 1.2

BOILER SPECIFICATION

Lift weight

12hx

to

30hx

25kg (55Ib)

35hx

26.5kg (58.4Ib)

Total weight (installed)

12hx

to

30hx

28kg (62Ib)

35hx

29.5kg (65Ib)

Gas connection Ø O.D. 15mm. copper

Heating Flow and Return connection Ø O.D. 22mm. copper

Condensate connection Ø I.D. 21.5mm. plastic

Electrical supply 230V~50Hz

Electrical rating 60W fused 3A

IP clasification IPX4D

Internal fuse rating on main PCB 2A

Gas supply (governed meter only) and cat. G20 natural gas

Gas Category I

2H

natural gas

Inlet gas working pressure 20mbar

Burner % CO2 case on 9.3 nominal

Burner % CO2 case off 9.3 nominal

12hx 15hx 18hx 24hx 30hx 35hx

m3/h 1.28 1.60 1.93 2.58 3.26 3.8

ft3/h 45 56.5 68.1 90.9 115 134

m3/h 0.99 0.99 0.99 0.99 0.99 0.99

ft3/h 35.1 35.1 35.1 35.1 35.1 35.1

PLEASE REFER TO THE COMMISSIONING SECTION

max. 12.1 15.1 18.2 24.4 30.8 35.8

min. 9.4 9.4 9.4 9.4 9.4 9.4

max. 12 15 18 24 30 35.0

min. 9.3 9.3 9.3 9.3 9.3 9.3

90.7 90.5 90.4 90.3 90.3 90.0

Approximate max. gas rate
after 10 mins. from cold

Heat input NETT Q = kW

Heat output P = kW

Approximate min. gas rate
after 10 mins. from cold

Approximate gas rate
at part load.

SEDBUK rating

Band A

Flue type (all models) C13, C33, C53

NOx (all models) Class 5

8

2 Boiler Dimensions and Hydraulic Schematic

13938

Diagram 2.2

2.1 Boiler Dimensions and Hydraulic Schematic

All dimensions are given in millimetres (except as noted).

The general arrangment of the boiler is shown in diagram 2.1.
and the hydraulic and gas schematic, diagram 2.2.

The data label is positioned on the front of the inner casing
panel.

13937

Diagram 2.1

9

3 Boiler Location, Clearances and Ventilation

3.1 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.

3.2 Clearances

The boiler should be positioned so that at least the minimum
operational and servicing clearances are provided, see diagram

3.1.

Increased clearances would be benecial for the installation.
Where external access is not practicable, for ue installations

consideration should be given for the space required to insert

the ue internally, which may necessitate the clearance to be
greater than those specied in diagram 3.1.

3.3 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.

3.4 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.

3.5 Room Ventilation

The boiler is room sealed so a permanent air vent is not
required.

3.6 Cupboard or Compartment Ventilation

Due to the high efciency and hence low casing temperature

of this boiler, cupboard or compartment ventilation is not
necessary.
Leave existing air vents.

12792

Diagram 3.1

10

4 Flue Options and Terminal Clearances

Top horizontal telescopic ue (Ø60/100)
Part No. A2043600 - Section 10, page 20

Top horizontal standard ue (Ø60/100)
Part No. A2043400 - Section 10, page 24

Twin Flue

Twin Flue Adapter, concentric ue (Ø80)

Part No. A2011000 - Section 10, page 32

Diagram 4.1

Plume Management Kit

basic set, white, concentric ue

(Ø60/100) - Part No. A2044100 for
use with Part No. A2043400 and Part
No. A2043600 - Section 10, page 35

Vertical Flue

Vertical Flue Adapter, concentric ue (Ø60/100)

Part. No. A2024600 - Section 10, page 29

Vertical ue terminal kit, concentric ue (Ø60/100)

Part. No. 2000460480 - Section 10, page 29

Direct rear telescopic ue (Ø60/100)
Part No. A2043500 - Section 10, page 28

11

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

H* and J* 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.

Diagram 4.2

4 Flue Options and Terminal Clearances

Diagram 4.3

4.1 Flue Options

There are various ue options to choose from as illustrated in
diagram 4.1. The ue lengths and installation are described in

section 10.

4.2 Flue Terminal Position

In GB the minimum acceptable siting dimensions for the

terminal from obstructions, other terminals and ventilation
openings are shown in diagram 4.2.

In IE 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.

4.3 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 4.3.
A suitable guard is manufactured by: ­Tower Flue Components
Morley Rd.
Tonbridge
Kent
TN9 1RA.
Size: 280mm x 280mm x 270mm.

12

0

5

10

15 20

25

30

Flow Rate (litres/min)

24kW

30kW

Pressure Loss (metres)

15kW

35kW

5 Water Systems - General

5.1 General

This boiler is designed to provide central heating from a fully
pumped open vented or sealed water system and domestic
hot water using a fully indirect cylinder.

5.2 Draining Points

Draining taps must be provided at all low points of the system,
which will allow the entire system to be drained.
Draining taps shall be to the current issue of BS2879.

5.3 Pump

The pump should be tted on the ow pipe from the boiler and

have isolating valves each side.
A variable duty pump should be set to give a temperature

difference of no greater than 200C between the ow and

return, with the thermostat set at “MAX”, which is about 800C,

to give a ow rate as given in the table.

See chart for pressure loss of the boiler, diagram 5.1.
High resistance microbore systems may require a higher duty
pump.

5.4 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 shown in diagram 5.2. The ow rate through the boiler

must not be allowed to fall below that given in diagram 5.1.

5.5 Bypass

A system bypass is required and should be tted at least 1.5

metres away from the boiler, refer to the current issue of the

central heating system specications (CHeSS).

5.6 Unvented DHW System

Where a storage system will not have a vent to atmosphere
the installation must comply with the building regulations and
local Water Company bylaws, see also the current issue of
BS5546 and BS6700.

If tting to an existing system the local authority should be

informed.

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”.

Diagram 5.1

14401

5.7 Water Treatment

Existing system- It is ESSENTIAL that prior to installing the

new boiler the system is thoroughly ushed.

New system- For optimum performance after installation, 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
Restorer or Salamander corrosion guard cleaner.

IMPORTANT: Ensure all cleanser is removed from the whole
system before adding an inhibitor.

For long-term corrosion protection, after ushing, an 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.

13

5.8 Vented (Open) Water System

The boiler must be supplied from an unrestricted water
supply taken from a feed and expansion cistern situated at a
maximum height of 27 metres (90ft) above the boiler.

The cold feed must be 15mm minimum size.

The vent must rise continuously and be unrestricted.

It is important that the relative positions of the pump, cold feed
and open vent are as shown in diagram 5.2.

5.9 Combined Feed and Vent

For combined feed and vent, a 22mm pipe must be tted in

accordance with BS 5449.

5.10 Domestic Hot Water Cylinder

SINGLE FEED INDIRECT CYLINDERS ARE NOT SUITABLE
The domestic hot water cylinder must be of the double feed
fully indirect coil type.

5.11 Draining Points

Draining taps must be provided at the lowest points of the
system, which will allow the entire system to be drained.
A draining point for the appliance is provided at the position
shown in diagram 5.3.

Diagram 5.3

14506

5 Water Systems - Open Vented

Diagram 5.2

13147

DRAIN
POINT

14

5 Water Systems - Sealed

5.12 Sealed Water Systems

The installation must comply with the appropriate
requirements of the current issue of BS4814, BS5449,
BS6759, BS6798 and BS7074 Part 1 and 2.
See diagram 5.4 for a suggested layout.

5.13 Safety Valve

A safety valve must be tted to a sealed system.

It shall be preset, non-adjustable with a lift pressure of 3 bar,
incorporating seating of a resilient material, a test device and
a connection for drain.
The drain from the safety valve must be routed outside the
building, must not discharge above an entrance or window
or any type of public access area, be clear of any electrical

ttings and positioned so that any discharge can be seen.

5.14 Expansion Vessel

A diaphragm type expansion vessel, conforming to the current
issue of BS4814 (see also BS7074 Part 1 and 2) must be
connected at a point close to the inlet side of the circulating
pump, see the diagrammatic layout, diagram 5.4.
The expansion vessel volume depends on the total water
system volume and the initial system design pressure. For
any system an accurate calculation of vessel size is given in
the current issue of BS5449 and BS7074 Part 1.
Example: For an initial design pressure of 0.7 bar, the mini­mum total vessel volume required is 0.063 x Total System
Volume.
NOTE: A higher initial design pressure requires a larger vol­ume expansion vessel.
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”.
The charge pressure must not be less than the static head
of the system, that is, the height of the highest point of the
system above the expansion vessel.

Diagram 5.4

14017

5.15 Pressure Gauge

A pressure gauge with a set pointer and covering at least 0 to

4 bar (0 to 60 lb/in2) shall be tted permanently to the system
in a position where it can be seen when lling the system.

5.16 Domestic Hot Water Cylinder

SINGLE FEED INDIRECT CYLINDERS ARE NOT SUITABLE
The domestic hot water cylinder must be of the double feed
fully indirect coil type. It must be suitable for working at a
gauge pressure of 0.35 bar above the safety valve setting.

15

TEMPORARY
CONNECTION

HOSE
UNION

HOSE

UNION

SUPPLY

PIPE

CONTROL
VALVE

CONTROL

VALVE

DOUBLE
CHECK
VALVE

HEATING
CIRCUIT

DRAIN
POINT

SUPPLY

PIPE

AIR GAP

TUNDISH

CONTROL

VALVE

CONTROL

VALVE

TYPE CA BACKFLOW

PREVENTION DEVICE

BOILER

RETURNFLOW

BOILER

RETURNFLOW

HEATING
CIRCUIT

DRAIN
POINT

Method 1

Method 2

Diagram 5.5

11680

5 Water Systems - Sealed

5.17 Water Makeup

Provision should be made for replacing water loss from the
system using a make up bottle mounted in a position higher
than the top point of the system, connected through a non-re­turn valve to the return side of either the heating circuit or the
hot water cylinder.
Alternatively, provision for make up can be made using a

lling loop.

5.18 Filling a Sealed Water System

Provision for lling the system at low level must be made, see

diagram 5.5. There must be no permanent connection to the
mains water supply, even through a non-return valve.

16

6 Installation Preparation

6.1 Appliance Pack

Please check the contents of packs as shown in diagram 6.1.

The packs are located in the top polystyrene packing.

Remove the carton sleeve and top pack then lift the boiler and
its polystyrene base support out of the lower pack.

6.2 Site Requirements

The boiler mounting wall should be suitable for the weight of

the appliance and be true and at.

NOTE: Due to the varied site conditions we do not supply

xings and advise that the installer should supply those which

are suitable.

6.3 Wall Template

Take the wall template from the document pack located within
the top polystyrene packing and place in the desired position

on the wall, giving due consideration to the required boiler
clearances, see section 3, and the ue you are tting.

Mark the position of the ue centre, if tting a side ue, extend
the ue centre line into the corner then 149mm along the

adjacent wall, see diagram 6.2.

For extended side ues, the ue hole centre should be

determined by extending the dashed inclined line on the
template to the side wall, then 149mm along the adjacent
wall, see diagram 6.2. This dashed line is drawn at 44mm/
metre (2.5°) rise from the boiler.

To allow for the ue 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 ue hole.

6.4 Flue Hole Cutting

External access ue installation can use a 105mm diameter

core drill.

Internal access only ue installation will need a 125mm

diameter core drill.

NOTE: The ue is designed with an internal fall of 44mm/

metre (2.5°), therefore the hole can be drilled horizontally.

If ue 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.

14020

Diagram 6.2

Diagram 6.1

14016

Documentation Pack (not illustrated)
Wall Template, User Instructions,
Installation and Servicing Instructions.

17

Diagram 7.1

12965

7 Boiler Fixing

7.1 Wall Hanging Bracket

The Wall Hanging Bracket is supplied in the main boiler
packaging.

Reposition the wall template over the ue hole and mark
the position of the xing holes for the hanging bracket, see

diagram 7.1.

NOTE: Due to the varied site conditions we do not supply

xings and advise that the installer should supply those which

are suitable.

Drill xing holes and insert suitable wall plugs.

Direct Rear Flue only - If external access is not available the

ue to be used should be assembled as described in sections

10.11 to 10.13 and inserted through the hole in the wall before

tting the wall hanging bracket.

7.2 Boiler Hanging

IMPORTANT: With regards to the Manual Handling

Operations, 1992 Regulations, the following lift operation
is deemed to be a one man lift, refer to section 17 Manual
Handling.

IMPORTANT: Direct Rear Flue only - The direct rear ue
must be tted before hanging the boiler, refer to sections

10.11 to 10.13, and the rear outlet cover plate should be
removed.

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 7.2.

Diagram 7.2

12959

18

8 Gas / Water and Appliance Connection

Diagram 8.1

8.1 Gas Connection

Before connection check the supply of local gas.
The gas supply connection is below the boiler, see diagram

8.1.
The whole of the gas installation, including the meter, should
be inspected, tested for tghtness and purged in accordance
with the current issue of BS6891 and in IE the current edition
of I.S.813 “Domestic Gas Installations”.

RETURN

FLOW

22mm compression
is the recommended
fixing for servicing
(not supplied)

Gas Connection

Water Connections

12799

14507

9.1 Condensate Drain Connection

The condensate drain connection, is positioned below the
boiler as shown in diagram 9.1. To discharge condensate to a
drain, the drain pipe should have a fall of a least 44mm/metre
(2.5°) 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 9.2.
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.

14508

Diagram 9.1

CONDENSATE DRAIN
CONNECTION

8.2 Water Connections

Provision is made for the water connections to be made from
above the boiler, see diagram 8.1. The position is shown on
the wall template.
Flush out the domestic hot water and the heating systems
before connecting to the boiler.

9 Condensate Connections

GAS SERVICE
ISOLATION
VALVE

GAS SUPPLY
PIPE IN

PRESSURE
TEST POINT

19

9 Condensate Connections

13000

Diagram 9.2

20

10 Telescopic Flue - Length, Preparation and Installation

14014

Horizontal Telescopic Flue

Diagram 10.1

14004

10.1 Flue Length

The maximum permissable horizontal ue length is 8 metres
plus the ue terminal assembly, this can be achieved by use

of the accessories, see diagram 10.3.

However should an additional 90º or 2 x 45º elbows be used
then the length MUST be reduced by 1metre.

The diagram 10.1 shows the length achievable by using the
kit A2043600.

When extension pipes are used the ue system must be

designed to have a continuous fall to the boiler of at least 2.5º
44mm/metre to allow condensate to run back into the boiler
and out via the condensate drain.

The ue can be installed from inside the building, when

access to the outside wall face is not practicable.

21

14005

Diagram 10.3

13765

10 Telescopic Flue - Length, Preparation and Installation

Diagram 10.2

22

10.2 Horizontal Telescopic Flue - A2043600

Refer to diagram 10.2 for kit contents.

10.3 REAR Flue

If a wall thickness is between 231mm min. to 441mm max.

then the ue can be used without extensions.

Remove the top ue outlet cover secured with four screws,

see diagram 10.4.

Using these screws inserted into the same holes on the boiler,

temporarily secure the ue elbow, measure the distance from
the outside wall to the butt joint, see diagram 10.5. If the
measurement ‘Y’ exceeds 525mm, then the appropriate length
of extension pipe is required.

If the dimension is less than 315mm DO NOT cut the ue, it

can project to a maximum of 600mm, refer to diagram 10.6. If

this is not desirable then a Standard ue MUST be used and

cut to length.

10.4 SIDE Flue

Remove the top ue outlet cover secured with four screws,

see diagram 10.4.

Using these screws inserted into the same holes on the boiler,

temporarily secure the ue elbow, measure the distance from
the outside wall to the butt joint, see diagram 10.7. If the
measurement ‘Y’ exceeds 525mm, then the appropriate length
of extension pipe is required.

If the dimension is less than 315mm DO NOT cut the ue, it

can project to a maximum of 600mm, refer to diagram 10.6. If

this is not desirable then a Standard ue MUST be used and

cut to length.

Diagram 10.6

12979

10 Telescopic Flue - Length, Preparation and Installation

Diagram 10.4

12978

Diagram 10.5

12806

Diagram 10.7

13224

23

Diagram 10.8

12929

Diagram 10.9

12977

Diagram 10.10

12930

10 Telescopic Flue - Length, Preparation and Installation

10.5 Flue Fitting

With the air duct seams aligned and the ue set to the

required length ‘Y’, mark the securing hole position in the air
duct. Drill a 3mm diameter hole at this position, take care not

to pierce the inner ue duct. Secure with screw provided and

tape the joint, see diagram 10.8.

Fit the sealing collar onto the locating ring on the ue terminal,

see diagram 10.9.

With the ue elbow removed, push the ue assembly into

the wall, externally or internally, until the end of the assembly
protrudes a short way from the inside face of the wall. This
will enable the internal trim ring (if required) to be positioned

and allow the ue assembly to be drawn back up to the ue

elbow.

Secure the ue elbow in position on top of the boiler with the

four screws supplied.

Draw the ue assembly from wall and engage the ue duct
into the elbow and butt t between the air duct and ue elbow.

Check the correct alignment of the ue.

Fit the securing collar in position, mark through two of the pre
drilled holes in the securing collar. Remove securing collar
and drill two 3mm diameter holes one in the elbow and one in

the air duct, take care not to pierce the inner ue duct. Fit the

securing collar and secure with screws provided, see diagram

10.10.

Slide the internal trim ring back against the wall, securing in
place with a small amount of sealant if required.

The cut ducts must be de-burred and all lings and debris

removed.

Insert the ue duct into the air duct terminal assembly,

remembering to engage the catch within the terminal.

NOTE: If the seals require lubricant to ease installation, do
not use mineral oils or grease, only silicon grease or water is
recommended.

24

10.6 Flue Length

The maximum permissable horizontal ue length is 8 metres
plus the ue terminal assembly, this can be achieved by use

of the accessories, see diagram 10.13.

However should additional 90º or 2 x 45º elbows be used then
the length MUST be reduced by 1metre.

The diagram 10.11 shows the length achievable by using the
kit A2043400.

When extension pipes are used the ue system must be

designed to have a continuous fall to the boiler of at least 2.5º
44mm/metre to allow condensate to run back into the boiler
and out via the condensate drain.

The ue can be installed from inside the building, when

access to the outside wall face is not practicable.

10 Standard Flue - Length, Preparation and Installation

Diagram 10.11

14015

14006

Standard Horizontal Flue

25

10 Standard Flue - Length, Preparation and Installation

Diagram 10.12

13222 13765

Diagram 10.13

26

10 Standard Flue - Length, Preparation and Installation

10.7 Standard Horizontal Flue - A2043400

Refer to diagram 10.12 for kit contents.

10.8 REAR Flue

Remove the top ue outlet cover secured with four screws,

see diagram 10.4.

Using these screws inserted into the same holes on the boiler,

temporarily secure the ue elbow, measure the distance
from the outside wall to the butt joint, see diagram 10.14. If
the measurement ‘Y’ exceeds 665mm, then the appropriate
length of extension pipe is required. The minimum dimension

is 187mm to suit a 75mm min wall thickness. The ue can

project to a maximum of 600mm, refer to diagram 10.15.

10.9 SIDE Flue

Remove the top ue outlet cover secured with four screws,

see diagram 10.4.

Using these screws inserted into the same holes on the boiler,

temporarily secure the ue elbow, measure the distance
from the outside wall to the butt joint, see diagram 10.16. If
the measurement ‘Y’ exceeds 665mm, then the appropriate
length of extension pipe is required. The minimum dimension
for Lhd is 227.5 and Rhd 177.5 to suit a minimum wall

thickness of 75mm. The ue can project to a maximum of

600mm, refer to diagram 10.15.

13224

Diagram 10.16

Left Hand illustrated

Diagram 10.14

13223

Diagram 10.15

12979

27

10.10 Flue Fitting

Remove the ue elbow.

Separate the ue duct from the terminal by twisting to release

the terminal catch, then pull out of the retaining seal, refer to
diagram 10.17.

The ue duct cutting length (L + 11mm.) is shown in diagram

10.17.

The air duct should be cut at the opposite end to the terminal

The plastic ue duct MUST be cut at the opposite end to the

terminal catch.

The plastic ue duct extensions MUST be cut at the opposite

end to seal.

The cut ducts must be de-burred and all lings and debris

removed.

Insert the ue duct into the air duct terminal assembly,

remembering to engage the catch within the terminal.

NOTE: If the seals require lubricant to ease installation, do
not use mineral oils or grease, only silicon grease or water is
recommended.

Fit the sealing collar behind the locating lugs on the ue

terminal, see diagram 10.18.

Push the ue assembly into the wall, externally or internally,

initially until the end of the assembly protrudes a short way
from the inside face of the wall. This will enable the internal

trim ring (if required) to be positioned and allow the ue
assembly to be drawn back into the ue elbow.

Secure the ue elbow in position on top of the boiler with four

torque headed screws supplied.

Draw the ue assembly from wall and engage the ue duct
into the elbow and butt t between the air duct and ue elbow.

Ensuring the correct alignment of the terminal.

Fit the securing collar into position, mark through two of the
pre drilled holes in the securing collar. Remove securing
collar and drill two 3mm diameter holes one in the elbow and

one in the air duct, take care not to pierce the inner ue duct.

Fit the securing collar and secure with screws provided, see
diagram 10.18.

Slide the internal trim ring back against the wall, securing in
place with a small amount of sealant if required.

NOTE: If the air and ue ducts have been correctly cut to the
instructions the sealing collar should t ush with the outside

wall, check this.

Diagram 10.17

12847

10 Standard Flue - Length, Preparation and Installation

Diagram 10.18

12658

28

10 Direct Rear Flue - Length, Preparation and Installation

28mm MAX
24mm MIN

10.11 Direct Rear ue - Telescopic

Part No. A2043500.

Refer to diagram 10.19 for kit contents.

10.12 Flue Length

Measure the distance from the outside wall to the inside wall
face. This measurement must not exceed 512mm (465mm
if the upward piping kit is used). If the dimension is less than

291mm DO NOT cut the ue, it can project to a maximum of

600mm, see diagram 10.15.

10.13 Flue Fitting

Set the ue to the required length ‘Y’ plus 24mm min to 28mm

max, see diagram 10.20, ensure the air duct seams line up.
Mark the securing hole position in the air duct. Drill a 3mm
diameter hole at this position, take care not to pierce the

inner ue duct. Secure with screw provided and tape the joint,

see diagrams 10.19.

Fit the sealing collar onto the locating ring on the ue terminal,

see diagram 10.19.

Push the telescopic terminal assembly into the wall, externally
or internally, initially.

Draw the telescopic ue through the wall and engage the

telescopic terminal assembly into the clamping band grips.
The telescopic terminal assembly must be pulled forward of
the clamping band grips by the dimension shown in diagram

10.21 to ensure a good seal when the boiler is located onto

the xing plate.

Ensuring the correct alignment of the terminal.

Secure the telescopic terminal assembly using the clamping
band supplied. The position of the clamping band securing
screw is important, refer to label and wall template.

IMPORTANT: CHECK THE CLAMPING BAND IS
SUFFICIENTLY TIGHTENED TO AVOID ANY MOVEMENT
OF THE FLUE WHEN FITTING THE BOILER.

Continue at the appropriate paragraph of section 7.

Diagram 10.20

12966

Diagram 10.21

12958

13203

Diagram 10.19

29

10 Vertical Flue - Length, Preparation and Installation

Diagram 10.22

12984

10.14 Vertical ue

The vertical ue system is available as an option where the

boiler position does not permit the use of the top horizontal

ue system.

The system is made up from accessories. The accessories

include terminal assembly, bends 45º and 90º, ue
extensions, xing bracket and appropriate weather collar, see

diagram 10.23.

The maximum permitted straight ue length is 8 metres plus
the terminal. for each 90º or 2x45º bends tted, the maximum

length must be reduced by 1 metre, see diagram 10.22.

NOTE: 2x45º bends can replace 1x90º bend if necessary.
When using 90º bends any horizontal extension pipe should
be inclined by a minimum of 44mm/metre (2.5º) towards
the boiler to facilitate condense removal, see (a) in diagram

10.22.

Alternatively use 45º bends to avoid horizontal runs, see (b) in
diagram 10.22.

The terminal siting should be as shown in diagram 4.2.

Measure the distance of ue length required for the

installation.

The ue must be designed with a continuous fall towards the

boiler.

30

10 Vertical - Flue Length, Preparation and Installation

Flue Installation

Remove the top ue outlet cover secured with four screws,

see diagram 10.4.

Refer to diagram 10.24 and secure the ue adapter in

position on top of the boiler with four screws supplied, making

sure the nib ts into the locating slot in the boiler casing to

ensure correct orientation.

NOTE: The rubber ‘O’ rings of each section should be
lubricated prior to assembly. Do not use mineral oils or
grease, silicon grease or water is recommended.

Secure the rst extension pipe to the ue adapter with the

securing collar supplied by positioning the collar centrally over
the joint, then tighten the two screws on the securing collar,
see diagram 10.25.

Fit more extension pipes as required using the collar and

screws supplied with each extension pipe. To t position the

collar centrally over the joint, tighten the two screws on the
securing collar. Using the holes provided in the securing
collar drill and insert the two self tapping srews supplied, see
diagram 10.26.

The rubber ‘O’ rings of each section should be lubricated prior
to assembly.

NOTE: Do not use mineral oils or grease, silicon grease or
water is recommended.

When installing the ue it is recommended that it is supported
every 2 metres and at every bend by a xing bracket.

Project the rise of the ue pipe to roof level and cut a 150mm

hole in the roof.

Flue Terminal Installation

(a) Pitched Roof

Fit the required pitched roof weather collar over the 150mm
hole in the roof. Make good the tiling or slating around the

collar incorporating the ashing of the weather collar. Position

the angle cap over the weather collar in the correct orientation
to attain the correct angle for your roof.

(b) Flat Roof

Fit the aluminium weather collar over the 150mm hole in the
roof ensuring a weather tight seal.

From above carefully place the ue terminal through the

weather collar.

Flue Terminal to Boiler Connection

Should the clearances above the boiler to roof not allow for

extensions, it is permitted to cut the ue terminal ensuring the
relationship of ue and air duct lengths are retained.

12969

Diagram 10.23

31

10 Vertical Flue Length, Preparation and Installation

Completion of Installation

With the ue terminal positioned in the roof the length of the
nal pipe can be determined. If a telescopic length cannot
be used, then a standard ue length can be cut to make the
correct length. Cut the ue to the desired length measuring

from the ‘O’ ring end and discard the plain end of the tube.
The cuts must be square and made free of burrs to allow
correct assembly.

NOTE: The ue pipe is 10mm longer than the air pipe, see

diagram 10.27.

Carefully push the terminal assembly upwards to allow room

for tting the nal ue piece. Fit a xing bracket to the terminal
assembly. Pull the terminal assembly down and join to the ue

system. Ensure that the terminal is making a weather tight

seal on the weather collar. Secure the xing bracket tted to
the terminal to the roong struts or a purpose made batton.

Diagram 10.24

12980

Diagram 10.25

12981

Diagram 10.26

12982

Diagram 10.27

12983

32

10 Twin Flue - Length, Preparation and Installation

Diagram 10.28

12987

33

10 Twin Flue - Length, Preparation and Installation

10.15 Twin ue

The twin ue system is available as an option when the top
horizontal or vertical ue system is not appropriate.

The system can provide an independent horizontal air inlet

and ue outlet, horizontal air inlet and vertical ue outlet or
vertical air inlet and ue outlet via a concentric terminal.

The system is made up from accessories, see diagram 10.29.

NOTE: The air and ue outlets do not have to be equal

lengths. 2x45º bends can replace 1x90º bend if necessary.

The maximum permitted combined (air inlet + ue outlet)
ue length is 40 metres plus terminal assemblies. For each
90° or 45º x 2 bends tted, the maximum ue length must be

reduced by 1 metre, see diagram 10.28.

NOTE: When using 90º bends any horizontal run should be
inclined by a minimum of 44mm/metre (2.5º) towards the
boiler to facilitate condense removal.

Alternatively use 45º bends to avoid horizontal runs in the ue

pipe.

Terminal Position

The clearances for a ue outlet are given in the "Flue Location
and Ventilation" section.

In addition the horizontal air inlet must not be closer than 300

mm from a ue outlet on the same wall or 1200mm from an
opposing ue outlet.

Diagram 10.29

12970

34

10 Twin Flue - Length, Preparation and Installation

Installation Details

The parts available for a twin ue system installation are

shown in diagram 10.29.

Boiler Connection

Remove the top ue outlet cover secured with four screws,

see diagram 10.4.

Place the twin ue adaptor onto the outlet of the boiler with

the air inlet to the left hand side, see diagram 10.30. Secure
the adaptor to the top panel with the screws provided. Care
should be taken when inserting the screw through the hole in
adaptor top.

To facilitate engagement, it is recommended that the rubber
‘O’ rings are lubricated with silicone grease or water prior to
assembly.

Air and Flue Pipe Installation

The air and ue pipes can now be built up from the boiler.

The ue must be designed with a continuous fall towards the
boiler. If using the horizontal ue pipe or 90° bends the pipe

must be inclined at 44mm/metre (2.5°) minimum, see diagram

10.28.

Alternatively if space allows, use 45° bends in place of 90º
bends.

The rubber ‘O’ rings of each section should be lubricated prior
to assembly with silicone grease.

When building the ue up it is recommended that it is
supported every 2 metres and at every bend by a xing

bracket.

Horizontal Terminal Installation

With due consideration to terminal clearances mentioned in
section 4.2 drill the one or two holes as required with a 90mm
core drill.

Push the horizontal terminal through the wall allowing approx.
100mm to protrude outside.

Push a grey rubber wall seal onto either side of the wall
ensuring that both wall seals are pushed up to the wall
surface, see examples (b) and (c) diagram 10.28.

Vertical Terminal Installation

With due consideration to terminal clearances mentioned in

Section 4.2, project the rise of the ue pipe to roof level and

cut 150mm hole in the roof.

(a) Pitched Roof

Fit the required pitched roof weather collar over the 150mm
hole in the roof. Make good the tiling or slating around the

collar incorporating the ashing of the weather collar. Position

the angle cap over the weather collar in the correct orientation
to attain the correct angle for your roof. One way round gives
a pitch of 25°-38° and the other gives 37°- 50°.

(b) Flat Roof

Fit the aluminium weather collar over the 150mm hole in the
roof ensuring a weather tight seal.

Diagram 10.30

12985

Horizontal Pipes-Completion of Installation

Having built the pipe(s) from the boiler to the terminal(s), the

length of the nal pipe piece can be determined. Cut pipes at

the opposite end to the ‘O’ ring seal making square and free
from burrs. Push the horizontal terminal through the wall to

engage the nal pipe piece and pull back ensuring the grey

wall seals are fully pulled up to the outside and inside wall
faces.

Vertical Pipes-Completion of Installation

Refer to diagram 10.28.

For installation of (a), attach the twin pipe to concentric

ue adaptor, part number A2011600, to the base of vertical

terminal assembly. For installation of (b), attach the single
pipe to concentric adaptor, part number A2011500, to the base
of vertical terminal assembly.

With the vertical terminal assembly positioned in the roof,

the length of the nal pipe can be determined. Cut the ue

to the desired length measuring from the ‘O’ ring seal end
and discard the plain end of the tube. The cut end should
be square and free from burrs. Carefully push the terminal

assembly upwards to allow room for tting the nal ue
piece(s). Fit a 100mm xing bracket to the terminal assembly

Part No2000460486. Pull the terminal assembly down and

join to the ue system. Ensure that the terminal is making a
weather tight seal on the weather collar. Secure the xing
bracket tted to the terminal to the roong struts or a purpose

made batton.

35

10 Plume Management Kit

10.16 Plume Management Kit

The Plume Management Kit: Part No. A2044100 (white) or
A2044000 (black) can be used to overcome many site issues.

The Plume Management Kit will t to the Top Horizontal

Telescopic, Rear Horizontal Telescopic and Standard

Horizontal Flue. This enables the ue products to exhaust

further away from the boiler, thereby reducing the impact of
pluming.

NOTE: The ue air inlet can be sited closer to doors, opening

windows and air bricks, than stated in section 4.2, see
diagram 10.31.

The maximum length of the Plume Management Kit must NOT

exceed 6m with a horizontal concentric ue length of 2m max.

For each 90o bend or 2 x 45o bends the maximum length of
the Plume Management Kit must be reduced by 1m.

For more information contact Glow-worm, refer to page 2.

The Plume Management Kit is supplied with installation
instructions.

Refer to BS5546 or BS6798 for advice on disposal of boiler
condensate.

Diagram 10.31

12997

36

11 Electrical Connection

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 both the plug
and socket comply with the current issue of BS1363.
This boiler is suitable for installation in bathroom zones
2 and 3.

11.1 Electrical Wiring

Remove the electrical cartridge from the ttings pack.

Remove the securing screw to open the cartridge, see
diagram 11.1.
NOTE: There are two screws supplied loose in the electrical
cartridge, these will be required to secure the cartridge into
the electrical interface housing.
Slacken the cable strain relief screws in the electrical
cartridge, see diagram 11.1.
Route the mains supply and system cables through the strain
relief and connect to the relevant plug, see diagram 11.2.

11.2 Pump Wiring

Ensure that a seperate pump supply cable is routed through
the strain relief and connected to the relevant plug, see
diagram 11.2.
Slacken the cable strain relief and route the pump electrical
supply cable and connect as shown in diagrams 11.1 and

11.2.

ELECTRICAL
CARTRIDGE

CABLE STRAIN
RELIEF

SECURING
SCREW

Diagram 11.1

13905

Diagram 11.2

13457

37

13906

11 Electrical Connection

ELECTRICAL
CARTRIDGE

FIXING
SCREWS

Diagram 11.3

11.3 Electrical Cartridge Securing

Close the cartridge and secure with the previously removed
screw.
Push the electrical cartridge into the interface housing on
completion of the wiring, see diagram 11.3.
Secure with the two cartridge retaining screws provided in the
cartridge body.

11.4 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.

NOTE: If you require to test the appliance refer to section 14.

12 Commissioning

12.1 Preliminaries - All Systems

The commissioning should be carried out by a competent
person in accordance with the current issue of BS6798.
DO NOT operate the boiler without water.

Make sure that the system has been thoroughly ushed

out with cold water and that all cleanser, if used, has been
removed.
Isolate the boiler from the mains electrical supply.
Test for gas tightness and purge air from the gas supply.

12.2 Filling the Heating Circuit

With the gas service isolation valve closed and with no
demand from any external controls.

1. Fill the heating system.

Sealed system only - ll the system to a pressure of

1.0bar.

2. Vent all air from the system - repeat as
neccessary until the system is full and all the air has
been vented.

12.3 Gas Supply

The gas valve is factory set for natural gas (G20) and should
need no adjustment. Turn on the gas supply at the isolation
valve, see diagram 12.1. Check the supply pressure at the
pressure test point is 20mbar.

Diagram 12.1

14507

GAS SERVICE
ISOLATION
VALVE

GAS SUPPLY
PIPE IN

PRESSURE
TEST POINT

38

12 Commissioning

12.3 Initial Lighting

DO NOT operate the boiler without water.

The lighting procedure of the boiler is fully automated.
Refer to diagram 12.2.

1. With no demand from any external controls, switch on the
electrical supply to the boiler.
Open the gas service isolation valve, see diagram 12.1.

2. Press and hold the “ Mode “ button of the boiler user

controls for 2 seconds, the Central Heating symbol,

will ash. Use the “SELECTOR” buttons to adjust CH

temperature.
After 10 seconds of inactivity the display will reset to indicate
the water temperature.

3. Turn ON your external controls and select the room
temperature required.
The boiler will operate automatically.
NOTE: The display will indicate the Heating system water
temperature or a fault code if in a fault condition.
NOTE: After ignition the boiler will ramp slowly to full rate
rather than going immediately to full rate. This is an adaptive
feature to cope with small system requirements.
After a period of 10 minutes, check that the supply inlet
pressure of the boiler is still 20mbar, disconnect the pressure
gauge.
NOTE: The burner pressure cannot be measured at the gas
valve as it is altered by the suction of the fan and modulated
according to demand.

14249

APPROXIMATE GAS RATES

MODEL NATURAL GAS G20
m3/h ft3/h
12hx 1.28 45
15hx 1.60 56.5
18hx 1.93 68
24hx 2.58 91
30hx 3.26 115
35hx 3.8 134

Diagram 12.2

14513

12.4 Gas Rates

Should any doubt exist about the gas rate, check it using the
gas meter test dial and stop watch. Make sure that all other
gas burning appliances and pilot lights are off.
It should be noted that this appliance will modulate the heat
input according to demand. This may affect the gas rates
measured if the appliance reaches its operating temperature
during the measurement.
The approximate gas rates:

In the unlikely event that the gas valve needs adjusting, refer
to section 13.9.

MODE

MODE

39

12 Commissioning

12.5 Range Rating

These boilers are fully modulating, therefore it is not
necessary to range rate them, however, if desired, you can
adjust the boiler in 1kW increments between 10 and maximun
output of your appliance, as follows:

a) Press and hold the ‘MODE’ and “+” button for 5

seconds. The display will change to ashing ‘0’.
b) Use the ‘+’ or ‘-’ button to scroll to 96.
c) Press and hold ‘MODE’ 5 seconds to conrm.
d) The display now shows a ashing ‘d. 0’.

e) The part load setting is displayed in kW.
Press ‘MODE’ the max rate will be indicated, to

change the value to the desired setting, use the ‘+’

or ‘-’ button.

f) Press ‘MODE’ for 5 sec to conrm the new setting

has been saved.

g) Press and hold ‘MODE’ and “+” to exit.

12.7 Completion

Adjust the boiler temperature control and any system controls
to their required settings.
GB: It is a requirement that the “Benchmark” Installation
Commissioning and Service Record is completed and left wth
the user.
IE: it is necessary to complete a “Declaration of Conformity” to
indicate compliance to I.S.813. An example of this is given in
the current edition of I.S.813.

Testing Flue Gases: If any doubt exists that the ue products

are not exhausting correctly, investigate by use of a gas
analyser (FGA).

12.8 Instruct the User

Demonstrate, then instruct the User about the lighting
procedure and heating system controls operation.
Advise the user on the use and maintenance of any scale
reducer and pass on any relevant instructional documents.

Advise that to ensure the continued efcient and safe

operation of the boiler it is recommended that it is checked
and serviced at regular intervals. The frequency of servicing
will depend upon the installation conditions and usage, but in
general, once a year should be enough.
Draw attention, if applicable, to the current issue of the Gas
Safety (Installation and Use) Regulations, Section 35, which
imposes a duty of care on all persons who let out any property
containing a gas appliance in the UK.
The user shall not interfere with or adjust sealed components.
It is the Law that any servicing is carried out by a competent

person.

Advise the user that, 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.

Advise the user of the precautions necessary to prevent
damage to the system, boiler and the building, in the event of
the heating system being out of use during frost or freezing
conditions.
Advise the user that the permanent mains electrical supply
SHOULD NOT be switched off, as the built in frost protection
and pump/valve saver program will not operate.
Advise the User 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, relling and pressurising MUST be carried out by a
competent person.
Leave these instructions and the ‘Benchmark’ Installation,
Commissioning and Service Record with the user.

kW m3/hr ft3/hr kW m3/hr ft3/hr

35 3.7 131 22 2.3 81.2
34 3.6 127 21 2.2 77.7
33 3.5 124 20 2.1 74.2
32 3.4 120 19 2.0 70.6
31

3.3 117 18 1.9 67.1
30 3.2 113 17 1.8 63.6
29 3.1 109.5 16 1.7 60.0
28 3.0 106 15 1.6 56.5
27 2.9 102.4 14 1.5 53.0
26 2.8 98.9 13 1.4 49.5
25 2.6 91.8 12 1.3 45.9
24 2.5 88.3 11 1.2 42.4
23 2.4 84.8 10 1.12 38.9

12.6 Testing - Heating System

Check that all external controls are calling for heat. The boiler

will re automatically. Fully open all radiator valves, ow
control valve and bypass valve if tted.
Balance the radiators as required and if tted adjust ow

control valve to give the required system differential. Turn off
all radiators that can be shut off by the user and check to see
if less than the maximum differential allowed of 200C can be

achieved across ow and return.

Allow the system to reach maximum temperature then switch
off the boiler by isolating from the electrical supply.
Drain the entire system rapidly whilst hot, using the drain tap
at the lowest part of the system. Fill and vent the system as
described previously in section 12.2

Lock or remove the handle from controls valve, if tted.

40

13 Servicing

Diagram 13.2

13.1 General Inspection

Before servicing the appliance inspect the following and then
carry out the functional checks:

1. Condition of case and ue.

2. Flue terminal for obstructions.

3. Electrical supply connections.

4. Water connections.

5. Gas connection.

6. System pressure.
Correct any fault before continuing.

13.2 Functional Checks

With the appliance operational carry out the following:

COMBUSTION CHECK - with a ue gas analyser as

described in section 13.9.

GAS RATE CHECK - the gas rates, refer to section

12.4.
If the gas rate requires adjustment you

MUST NOT
adjust the gas valve without a gas analyser, refer to
section 13.9.

If you cannot measure the gas rate it is acceptable to
measure the combustion rate as described in section 13.9,
however, if you do not have either facility then the appliance
MUST be turned off and disconnected until such equipment is
available.

If the Combustion and Gas rate checks did not require
adjustment then it will not be necessary to service the
Combustion Chamber, Burner, Heat Exchanger or Spark
Electrode, proceed to section 13.11.

If the combustion or gas rate requires adjustment you must
complete the servicing as described in sections 13.3 to

13.8, then repeat the functional checks before proceeding to
section 13.11 to complete the servicing.

13.3 Servicing the Appliance

On completion of paragraphs 13.1 and 13.2, proceed with the
following.All routine servicing requirements can be achieved
by the removal of the front panel, see diagram 13.1.

Before commencing with a service or replacement of parts the
boiler should be isolated from the electrical and gas supplies,
see diagram 13.2 for the position of the gas service isolation
valve.

14381

Diagram 13.1

14291

GAS SERVICE
ISOLATION
VALVE

IMPORTANT NOTES:

1. To ensure the continued efcient and safe operation of the boiler it is recommended that it is checked and

serviced at regular intervals. The frequency of servicing will depend upon the particular installation and usage,
but in general once a year should be enough.

2. It is the Law that any servicing is carried out by a competent person.

3. Before commencing with a service or replacement of parts the boiler should be isolated from the electrical
supply and the gas supply should be turned off at the gas service isolation valve.

4. 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.

5. If any electrical connections have been disconnected and after their connection, checks to the earth continuity,
polarity, short circuit and resistance to earth must be repeated using a suitable multimeter, as described in
section 14.

6. On completion the “Benchmark” Service Record should be completed.

41

13 Servicing

13.4 Spark Electrode

NOTE: If the functional checks did not indicate poor

combustion then it is not necessary to service this

component.

Ease the securing clips away from the sump to release the

retaining catch then push the ue hood up to disengage from

the sump, see diagram 13.3.

To remove, swivel ue hood 90o and pull down and out, see

diagram 13.3.

Check seal for wear or damage and replace if necessary.

IMPORTANT: Do not allow xings, nuts, screws, etc. to fall
into the open ue hood sump, use a temporary cover whilst

removing any parts.

Disconnect the spark electrode plug and earth lead. Remove
the two securing screws and withdraw the spark electrode
carefully from the combustion chamber, see diagram 13.4.

Inspect the tips for damage.

Clean away any debris and check the spark gap is 4mm.

Check the electrode gasket for signs of damage and replace
if necessary.

13.5 Burner

NOTE: If the functional checks did not indicate poor

combustion then it is not necessary to service this

component.

Disconnect the gas supply at the gas valve and electrical
connections, see diagram 13.5.

The Silencer (front) is a push t, so there is no need for tools
to remove or t, see diagram 13.6.

Release the igniter unit support bracket, see diagram 13.7.

Remove the fan retaining bracket.

To ease removal of the securing nut from the fan retaining

bracket, a at bladed screwdriver can be used in the position

shown and gently levered down as indicated, see diagram

13.8.

Remove the fan and gas valve assembly.

The silencer (rear) is a push t so no tools are required for its
removal or tting, see diagram 13.9.

Check the spark electrode gap is 4mm. Clean and adjust as
necessary, see diagram 13.4.

It should not be necessary to remove the spark electrode from
the burner during servicing.

Remove the anged nuts and studs that secure the burner,

note that two studs at the rear also hold the fan clamping
bracket, see diagram 13.10.

Clean the burner with a soft brush taking great care not to
damage the surface of the burner. DO NOT use wire or sharp
instruments to clean the mesh of the burner.

NOTE: The burner gasket should be inspected but will not
need replacing unless there are signs of wear or damage.

Follow the tightening sequence when re-tting the burner, see

diagram 13.10.

14406

14407

Diagram 13.3

Diagram 13.4

14408

42

GAS
VALVE

GAS
PIPE

ELECTRICAL
CONNECTION
(removed)

SECURING
SCREW (3)

TUBING
NUT

Diagram 13.5

14079

Diagram 13.6

13128

FAN

SECURING
NUT

FAN
RETAINING
BRACKET

Diagram 13.9

14288

Diagram 13.8

14081

Diagram 13.7

14409

13 Servicing

SECURING
NUT

SUPPORT

BRACKET
IGNITION
LEAD

SPADE
CONNECTOR

IGNITER
UNIT

EARTH
CONNECTION

ELECTRICAL
CONNECTIONS

43

13 Servicing

13.6. Heat Exchanger

NOTE: If the functional checks did not indicate poor

combustion then it is not necessary to service this

component.

Remove loose debris from inside the heat exchanger using a
soft brush and vacuum cleaner.

Carefully ush by spraying water into the heat exchanger, any

remaining debris should pass through the condensate trap
(Ensure the water is kept away from electrical components).

13.7 Condense Trap and Siphonic Drain

The condensate trap and siphonic drain does not normally
need servicing unless material deposits exceed beyond the

service ll level, see diagram 13.11.

To clean the condense trap remove the sump and rinse with
water.

Diagram 13.11

14089

LOCATING
SCREW

SERVICE FILL LEVEL

CONDENSE
TRAP AND SIPHONIC
DRAIN

SUMP

Turn anti-clockwise
to remove

SECURING
NUTS (6)

BURNER

FAN CLAMPING
BRACKET

Diagram 13.10

14410 14397

13.8 Casing panel seal check

NOTE: If the functional checks did not indicate poor

combustion then it is not necessary to service this

component.

Check the condition of the seal and replace if worn or
damaged.

To replace remove the old seal and thoroughly clean the
casing surfaces. Fit the new seals, these are supplied to the
correct lengths and are in four pieces, for use on the sides,
top and bottom.

14460

44

13 Servicing

13.9 Combustion Check

With the appliance operational connect the CO2 combustion

analyser to the ue elbow test point or if direct rear ue tted,

the test point shown in diagram 13.12.

IMPORTANT: Remember to replace the cap on
completion of the test.

A competent person only should carry out any adjustment to

the gas valve, refer to diagram 13.13.

Monitor the combustion reading and at max
rate the reading should be 9.3% ± 0.5.

Check the burner %CO2 at maximum rate (open a hot water
tap fully) is as shown in the “CHECK” column of the table
and if the reading falls within the tolerance, disconnect the

analyser, t the test point cap and return to functional checks

- gas rate.

If adjustment is required remove the front casing panel,
see diagram 13.1. Taking care not to touch any internal
components, proceed as follows:

Press the “reset” button on the controls fascia, release

and immediately press and hold in the “+” button. After

approximately 5 seconds “Hi” will be displayed. Pressing
the mode button when “Hi” is selected will force the boiler

to maximum rate, the display will ash between “Hi” and the

“default display” this will indicate the boiler has been forced to
maximum.

Adjust the maximum rate CO2 with the throttle to 9.3%.
(Rotate anti-clockwise to increase).

To exit the check sequences press the “mode” and “+” buttons

simultaneously, this will reset the boiler to the default display.

Monitor the combustion reading and at min
rate the reading should be 9.3% ± 0.5.

If adjustment proves necessary then proceed as follows:

Press the “reset” button on the controls fascia, release

and immediately press and hold in the “+” button. After

approximately 5 seconds “Hi” will be displayed. Pressing the

“+” or “-” buttons will cycle between “Hi” and “Lo”. Pressing

the mode button when “Lo” is selected will force the boiler

to minimum rate, the display will ash between “Lo” and the

“default display” this will indicate the boiler has been forced to
minimum.

Refer to diagram 13.13, remove the offset screw cover.

Adjustment of the CO2 at minimum rate is very coarse so
carefully adjust the CO2 with the offset adjustment to 9.3%.
(Rotate clockwise to increase).

Ret the offset cover and the cap on the test point.

To exit the check sequences press the “mode” and “+” buttons

simultaneously, this will reset the boiler to the default display.

NOTE: Check the casing panel is tted correctly giving an air

tight seal.

13.10 Gas Rate Adjustment

This appliance incorporates a pre-mix burner. The gas rate
should be correct if the combustion measured in section 13.9
is correct.

13.11 Service Completion

On completion of the service the “Benchmark” Service Record
should be completed.

Diagram 13.12

13028

Diagram 13.13

12776

14290

45

14 Fault Finding

14.1 Preliminary fault nding

The following checks should be performed before proceeding

onto specic diagnostics:

• Check the external electrical supply to the boiler is on and
a supply of 230V is present at the ‘L’ and ‘N’ terminals at the
installer interface.

For access remove and open the electrical cartridge, see
diagrams 11.3. and 11.1.

Test at the ‘L’ and ‘N’ terminals on the installer interface, refer
to diagrams 11.1 and 14.4.

• Check the electrical installation and appliance, carry out
tests for earth continuity, polarity, short circuit and resistance
to earth, using a suitable multimeter.

An aid to test

Remove the front casing panel, see diagram 14.1 and hinge
down the control box.

Unclip the rear cover to gain access to the main PCB.

Carry out the tests at connector plug X17, see diagram 14.2.
Check chassis earth at a bare metal point on the boiler.

• Check that there is a gas supply to the boiler and the gas
service isolation valve is turned on, see diagram 12.1.

• Check pressure at the gas service isolation valve, refer to
section 12.4.

• Check that the heating system pressure indicates at least

1mb, if not, ll and vent the system as described in section

12.2.

• Check that all external controls are on.

• Check the functional ow diagram, 14.5.

14.2 Fault Codes

Fault codes take priority over all other display functions in the
event of a fault occuring, refer to diagram 14.6.

If multiple faults occur the codes will be displayed for approx.
2 seconds, alternatively.

14.3 Fault Memory

The Fault memory stores details of the ten most recent faults.

To access this menu, refer to diagram 14.3:

a) Press and hold ‘MODE’ and ‘-’ buttons for 5 seconds.

b) The display will stop ashing and alternate between the

fault memory number and the fault code.

c) Press ‘+’ button to scroll through the fault memory

(Position 1 is most recent), see fault codes.

To exit this menu, press the ‘MODE’ button.

14.4 Diagnostic Menu

The Diagnostic Menu provides the ability to view and
change certain parameters. See diagram 14.8 for available
parameters.

14028

Diagram 14.3

Diagram 14.2

13845

14291

Diagram 14.1

14.5 Status Codes

The status codes provide information about the current
operating condition of the boiler and can be accessed through
the diagnostic display, refer to diagram 14.7.

46

14 Fault Finding

13917

Diagram 14.4

GAS
CONTROL
VALVE

HEATING FLOW
THERMISTOR

HEATING

RETURN

THERMISTOR

FAN

IGNITION
ELECTRODE

IGNITER
UNIT

MAIN CONTROL
BOARD

APPLIANCE
INTERFACE
BOARD

FLEXICOM HX

g/y

r

bk

gy

w

bk

bk

b

r

w

y

b

br

b

g/y

w

bk

b

r

g/y

br

g/y

b

r

r

br

b

gy

w

r

g/y

br BROWN
b BLUE
g/y GREEN/YELLOW

g GREEN

gy GREY

bk BLACK
y YELLOW

pk PINK

p PURPLE

or ORANGE

w WHITE

r RED

KEY

47

13012

Diagram 14.5

14 Fault Finding

48

14 Fault Finding

Diagram 14.6

14029

FAULT CODES

In all circumstances press the reset button to clear the fault. If the fault persists, consult the table below.

49

14 Fault Finding

Diagram 14.7

13131

STATE LISTS

State list - To access the state lists the ‘-’ button must be pressed for longer than 5 seconds until it

begins to ash ‘S’ and then a number to indicate the state. The state numbers are given below.

50

14 Fault Finding

DIAGNOSTIC CODES - LEVEL 1

Installer Access

14725

Diagram 14.8

d.99 State List (see diagram 14.7)

d.28 Option Relay 2

d.27 Option Relay 1

d.91 Internal Programmer type (for use with Options board kit) 0:24 hour (default) 1:7 day

N/A

Flow temperature setpoint

Description Range

intelligent control

Status additional heating pump (option)

Status central heating pump

> 8 no flame < 4 good flame

Minutes

Digital regulator status

Quantity (in hundreds)

N/A

Reserved for future use

To enter the diagnostics menu follow the procedure below:-

Press and hold the ‘MODE’ and ‘+’ buttons for approx 5 seconds until the screen changes. Use the ‘+’ or ‘-’ button to select the

number 96, this is the password. Hold the ‘MODE’ for approx 5 seconds when 96 is selected, when the screen changes release

the button. The screen will ash between ‘L1’ and a number. ‘L1’ indicates you have level 1 access, the number indicates
the diagnostic number below. Use the ‘+’ and ‘-’ to cycle through the selections below. To select a diagnostic number press

the ‘MODE’ button when the correct number is selected. The display will show the parameter value of the diagnostic number

selected. To return to the diagnostic number selector simply press the ‘MODE’ button. To change the parameter use the + or

- buttons. Once the value has been changed it must be saved by holding the ‘MODE’ button for approximately 5 seconds. This
will return to the diagnostic number selector.

Indicates read and write function - all other diagnostics are read only

51

15 Replacement of Parts

Diagram 15.1

15.1 General

Replacement of parts must be carried out by a competent
person.

Replacement parts that have associated components that
need replacing on removal, ie. ‘O’ ring seals, gasket, etc; will

be supplied and should be tted.

Before replacing any parts the boiler should be isolated from
the mains electric supply and the gas should be turned off
at the gas service isolation valve on the boiler, see diagram

15.1.

Ensure that components with electrical connections are
disconnected before removal.

Unless stated otherwise parts are replaced in the reverse
order to removal.

After replacing any parts always test for gas tightness and if
necessary carry out functional test of the controls.

For replacement of parts the front casing of the boiler will
need to be removed. To remove undo the two screws on the
underside of the front casing and lift off.

The side panels can be removed to aid replacement of parts.

To hinge a side panel undo and remove the four screws
securing each side panel to the boiler, two below and two at
the top.

15.2 Igniter Unit

For access, refer to section 15.1.

Remove ignition lead and electrical connections then remove
igniter unit by removing two securing screws, see diagram

13.7.

15.3 Ignition Lead

For access, refer to section 15.1.

Pull the spark plug style connector off the spark electrode
and the spade connector connected to the igniter unit, see
diagrams 13.4 and 13.7.

15.4 Silencer Assembly (front)

For access, refer to section 15.1.

Pull forwards to remove.

The silencer is a push t so no tools or xings are required
for its removal or tting, see diagram 13.6.

15.5 Gas Valve

Remove the three securing screws, holding the gas valve to
the fan, see diagram 13.5.

Remove the gas valve.

After re-tting check the combustion CO2 and adjust if

necessary, refer to section 13.9, Combustion Check.

After assembly test for gas tightness and purge in accordance
with the current issue of BS6891or in IE, the current edition of
I.S.813 “Domestic Gas Installations”.

15.6 Flue Hood

For access, refer to section 15.1.

Pull the ue hood securing clips away from the ue hood
sump and push ue hood up slightly towards ue hood top,

see diagram 13.3.

To remove swivel ue hood 900 and pull down and out

towards front of boiler.

14383

15.7 Fan/Gas valve assembly

For access, refer to section 15.1.

Undo the tubing nut to remove the gas valve from the gas pipe
and any electrical connections, see diagram 13.5.

Remove the securing nut holding the fan retaining bracket,
press down on burner to ease removal of securing nut. Slide
out the fan retaining bracket.

Lift front of bracket away from stud and pull forward to release
the fan, see diagram 13.8.

Lift fan/gas valve assembly up and forward away from locating
studs.

Remove fan gasket and replace.

To replace the fan and retaining bracket correctly, insert into
slots on fan clamping bracket and locate onto lugs on the
burner, see diagram 13.10.

15.8 Silencer assembly (rear)

For access, refer to section 15.1.

Remove the fan/gas valve assembly, see section 15.7.

Pull Silencer rear away from fan/gas valve assembly.

The rear silencer is a push t so no tools or xings are
required for its removal or tting, see diagram 13.9.

15.9 Spark Electrode

For access, refer to section 15.1.

Remove the spark plug lead and earth lead.

Remove the two securing nuts.

Withdraw the spark electrode by slowly pulling up and leaning
it forward towards the centre of the heat exchanger to ensure
that the electrode does not foul on the hole in the burner
casing.

Check spark gap, see diagram 13.4.

PRESSURE
TEST
POINT

GAS SERVICE
ISOLATION VALVE

GAS SUPPLY IN

CONDENSATE

52

15 Replacement of Parts

15.10 Burner

For access, refer to section 15.1.

Remove igniter unit, ue hood, fan and gas valve assembly

and spark electrode lead, refer to relevant sections.

Remove the anged nuts and studs that secure the burner,

note that two studs at the rear also hold the fan clamping
bracket, see diagram 13.10.

NOTE: The burner gasket should be inspected but will not
need replacing unless there are signs of wear or damage.

IMPORTANT: Do not allow xings, nuts, screws, etc. to fall
into the open ue hood sump, use a temporary cover whilst

removing any parts.

15.11 Condensate Trap

For access, refer to section 15.1.

Remove securing screw, see diagram 13.11.

Disconnect the exible condense drain pipe from the external

plastic drain pipe beneath the boiler.

Carefully pull the condensate trap down and forward so as not
to spill its contents. The trap shoud be removed complete with

the sealing grommet and exible condensate drain pipe.

15.12 Heating Flow Thermistor

For access refer to section 15.1

Remove the silencer front, fan/gas valve assembly and ue

hood for access. See relevant sections.

Refer to diagram 15.2.

15.15 Casing Seal

Refer to Section 13.8

15.16 Access to User interface and Main PCB

For access, refer to section 15.1.

Hinge down the control box and unclip the rear cover to gain
access.

Remove electrical connections from main PCB noting their
positions for replacement.

Unclip main PCB and remove, see diagram 15.5.

Unclip user interface and remove.

For replacement, see diagram 15.6 and ensure that the user

interface connection cable is retted.

NOTE: When re-tting any of the control boards make sure

you support the control box to avoid straining hinges as you
push down and clip back into place.

Remove the electrical connections from the thermistor.

Remove the retaining clip from the ow pipe.

Remove the thermistor from the retaining clip.

Note that the polarity of the wiring to thermistors is
unimportant.

HEATING FLOW
THERMISTOR

FLOW PIPE

Diagram 15.2

12964

53

Diagram 15.3

14379

15 Replacement of Parts

Diagram 15.4

14384

Diagram 15.5

14278

HEATING RETURN
THERMISTOR

RETURN PIPE

DRAIN
POINT

RETAINING
CLIP

RETURN
PIPE

FLANGED
ELBOW

15.13 Heating Return Thermistor

For access, refer to section 15.1.

Refer to diagram 15.3.

Remove the electrical connections from the thermistor.

Remove the retaining clip from the return pipe.

Remove the thermistor from the retaining clip.

Note that the polarity of the wiring to thermistor is
unimportant.

15.14 Heat Exchanger

For access, refer to section 15.1.

Drain down the boiler heating circuit

Remove the silencer front

Pull forwards to remove.

The silencer is a push t so no tools or xings are required for
its removal or tting, see diagram 13.6.

Remove the ue hood front

Ease the securing clips away from the sump to release the

retaining catch then push the ue hood up to disengage from

the sump, see diagram 13.3.

To remove, swivel ue hood 90° and pull down and out, see

diagram 13.3.

Remove the igniter unit with support bracket

Disconnect the electrical connections and ignition lead.

Release the igniter unit support bracket.

Remove the igniter unit assembly, see diagram 13.7.

Remove the gas valve/fan

Disconnect the tubing nut at the gas valve, see diagram 13.5.

Remove the fan retaining bracket, see diagram 13.8.

To ease removal of the securing nut from the fan retaining

bracket, a at bladed screwdriver can be used in the position

shown and gently levered down as indicated.

Remove the spark electrode plug and earth connection.

Remove the fan and gas valve electrical connections.

Remove the fan and gas valve assembly.

Remove the condensate trap

Remove the drain outlet pipe from the base of the trap, see
diagram 15.1. Remove the condensate drain securing screw
and carefully pull the trap forward, see diagram 13.11.

Drain the heat exchanger

Drain the heat exchanger using the drain point on the right
hand side of the heat exchanger, see diagram 15.4.

54

15 Replacement of Parts

Diagram 15.6

14385

Diagram 15.7

14402

SECURING
SCREW

SECURING
SCREW

DRAIN
POINT

HEAT
EXCHANGER
(with the burner and flow pipe
removed for clarity)

Remove the heat exchanger

Undo the screws securing the anged elbow on the top right

hand side of the heat exchanger and remove the retaining clip

from the anged elbow, see diagram 15 5.

Remove retaining clip from the anged elbow on the bottom of

the heat exchanger, see diagram 15.4.

Remove screws securing the heat exchanger, one on top and
one underneath the heat exchanger, see diagram 15.6.

Lift up heat exchanger slightly to disengage it from its hanging
bracket.

Remove the heat exchanger by pulling forward, then pulling
to the right to disengage the return pipe and tilting backwards
to ease removal complete with sump. Discard the heat

exchanger and anged elbows.

Remove the burner

Remove the six anged nuts and two studs that secure the

burner, note that the two studs also hold the fan clamping
bracket, see diagram 15.7.

Taking great care not to damage the surface of the burner.

NOTE: Replace the burner gasket and follow the tightening

sequence when re-tting the burner, see diagram 15.7.

NOTE: Fit all replacement gaskets and seals when re-tting

parts.

Refer to Section 12.

Fill the boiler heating system.

Re-pressurise (sealed sysem only)

Check for any leaks.

Vent all air from the system.

Test for gas tightness, earth continuity, polarity, short circuit
and resistance to earth.

Light the boiler and carry out functional checks.

55

Diagram 15.8

13003

15 Replacement of Parts

Diagram 15.9

13003

Diagram 15.10

13004

15.15 Casing Seal

Refer to Section 13.8.

15.16 Access to User interface and Main PCB

For access, refer to section 15.1.

Hinge down the control box and unclip the rear cover to gain
access.

Remove electrical connections from main PCB noting their
positions for replacement.

Unclip main PCB and remove, see diagram 15.8.

Unclip user interface and remove.

For replacement, see diagram 15.9 and ensure that the user

interface connection cable is retted.

NOTE: When re-tting any of the control boards make sure

you support the control box to avoid straining hinges as you
push down and clip back into place.

15.17 Control Box

For access, refer to section 15.1.

Hinge down the control box and unclip the rear cover to gain
access.

Remove relevant electrical connections from main PCB and
grommets from the control box.

MPORTANT: Support the control box whilst undoing the
hinges.

Remove the hinge securing screws accessed from beneath
the boiler and remove the control box, see diagram 15.10.

15.18 Fuse - Main PCB - Control Box

For access, refer to section 15.16.

The fuse is located at the top left hand corner of the main
PCB, see diagram 15.8.

15.19 Installer Interface Electrical Cartridge

Remove the Installer Interface securing screw accessed from
beneath the boiler.

Carefully pull down the electrical cartridge, disconnect the
cables.

56

16 Spare Parts

Diagram 16.1

13013

1

2

3

4

5

6

7

8

Key No. Part No. Description GC No

1 0020020734 Fan *********

2 0020020763 Igniter unit *********

3 0020020781 Heating ow & return thermistor (2) *********

4 0020020735 Gas valve 12hx - 30hx *********

4 0020059600 Gas valve 35hx *********

5 0020020731 Spark Electrode *********

6 0020020728 Burner 12hx - 30hx *********

6 0020059601 Burner 35hx *********

7 0020023826 User interface *********

8 0020023825 Main P.C.B. *********

57

IMPORTANT. With regards to the Manual Handling Opera-

tions, 1992 Regulations, the following lift operation exceeds the
recommended weight for a one man lift.

General recommendations when handling

Clear the route before attempting the lift.
Ensure safe lifting techniques are used – keep back straight – bend us­ing legs. Keep load as close to body as possible. Do not twist – repo­sition feet instead. If 2 persons performing lift, ensure co-ordinated
movements during lift. Avoid upper body/top heavy bending - do not
lean forward/sideways. Recommend wear suitable cut resistant gloves
with good grip to protect against sharp edges and ensure good grip.
Always use assistance if required.

Removal of carton from delivery van

Recommend 2 person lift or 1 person with use of sack truck. If 1
person is performing lift, straddle the load, tilt and place carton into po­sition on truck. Recommend secure appliance onto truck with suitable
straps. Ensure safe lifting techniques are used – keep back straight
– bend using legs. Keep load as close to body as possible. If 2 persons
performing lift, ensure co-ordinated movements during lift. Always use
assistance if required.

Carriage of carton from point of delivery to point
of installation – ground oor.

Recommend 2 person lift or 1 person with use of sack truck. If 1 person
is performing lift, straddle the load, tilt and place carton into position on
truck. Recommend secure appliance onto truck with suitable straps.
Ensure safe lifting techniques are used – keep back straight – bend
using legs. Keep load as close to body as possible. If 2 persons per­forming lift, ensure co-ordinated movements during lift. Clear the route
before attempting the lift. If removing boiler from truck straddle the load
and tilt forwards to facilitate secure grip. Ensure safe lifting techniques
are used – keep back straight – bend using legs. Do not twist – repo­sition feet instead. Take care to avoid trip hazards, slippery or wet
surfaces and when climbing steps and stairs. Always use assistance if

required.

Carriage of carton from point of delivery to point
of installation – rst or higher oor, cellar.

Recommend 2-person lift or 1 person with use of sack truck. If 1 person
is performing lift, straddle the load, tilt and place carton into position on
truck. Recommend secure appliance onto truck with suitable straps.
Ensure safe lifting techniques are used – keep back straight – bend us­ing legs. Keep load as close to body as possible. If 2 persons perform­ing lift, ensure co-ordinated movements during lift. Avoid upper body/top
heavy bending - do not lean forward/sideways. Clear the route before
attempting the lift. If removing boiler from truck straddle the load and
tilt forwards to facilitate secure grip. Ensure safe lifting techniques are
used – keep back straight – bend using legs. Do not twist – reposition
feet instead. Take care to avoid trip hazards, slippery or wet surfaces
and when climbing steps and stairs. Always use assistance if required.

Carriage of carton from point of delivery to point

of installation – roofspace.

Recommend 2-person lift. Ensure co-ordinated movements during
lift. Avoid upper body/top heavy bending - do not lean forward/side­ways. Clear the route before attempting the lift. Take care to avoid trip
hazards, slippery or wet surfaces and when climbing steps and stairs.
When transferring appliance into roofspace, recommend 1 person to be
in roofspace to receive the appliance and other person to be below to
pass up and support appliance. Ensure safe lifting techniques are used
– keep back straight – bend using legs. Keep load as close to body as
possible. Always use assistance if required. It is assumed safe access,

ooring and adequate lighting are provided in the roof space. It is

recommended a risk assessment of the roof space area be carried out
before moving the appliance into the area to take into account access,

stability of ooring, lighting and other factors, and appropriate measures

taken.

Unpacking of appliance from carton.

Recommend 2 persons unpack appliance from carton. Always keep
working area clear. Recommend cut base end of carton and open

carton aps, then tilt boiler forwards from its side onto its base and

remove carton by sliding up over the boiler. Ensure safe lifting tech­niques are used – keep back straight – bend using legs. Keep load as
close to body as possible. Always use assistance if required. Dispose

17 Manual Handling

of packaging in a responsible manner. Recommend wear suitable
cut resistant gloves with good grip to protect against sharp edges and
ensure good grip when handling appliance outside packaging.

Positioning of Appliance for Final Installation

– no obstructions.

This appliance is deemed to be a one person lift when removed from
the carton. Fit bracket securely onto wall before lifting appliance into

position. Obtain rm grip on front and sides of appliance, lift upwards,

ensure stable balance achieved and lift upwards to position in place
on bracket. Ensure safe lifting techniques are used – keep back

straight – bend using legs - when lifting load from oor level. Do not

twist – reposition feet instead. Keep boiler as close as possible to
body throughout lift to minimise strain on back. Ensure co-ordinated
movements to ensure equal spread of weight of load. Always use
assistance if required. Recommend wear suitable cut resistant gloves
with good grip to protect against sharp edges and ensure good grip
when handling appliance.

Positioning of Appliance for Final Installation

– above worktop, foreseeable obstructions etc.

This appliance is deemed to be a one person lift when removed from
the carton. Fit bracket securely onto wall before lifting appliance into

position. Obtain rm grip on front and sides of appliance, lift upwards,

onto worktop if practicable. Ensure stable balance achieved and lift
upwards to position in place on bracket. If 2 persons positioning onto

bracket obtain rm grip at front and sides/base of boiler. Ensure co-

ordinated movements during 2 person lifts to ensure equal spread of
weight of load. Ensure safe lifting techniques are used – keep back

straight – bend using legs - when lifting load from oor level. Do not

twist – reposition feet instead. Keep boiler as close as possible to body
throughout lift to minimise strain on back. Avoid upper body/top heavy
bending - do not lean forward/sideways. Always use assistance if re­quired. Recommend wear suitable cut resistant gloves with good grip
to protect against sharp edges and ensure good grip when handling
appliance.

Positioning of Appliance for Final Installation –

within compartment etc. restricting installation.

This appliance is deemed to be a one person lift when removed from
the carton. Fit bracket securely onto wall before lifting appliance into

position. Obtain rm grip on front and sides of appliance, lift upwards,

onto worktop if practicable. Ensure stable balance achieved and lift
upwards to drop into place onto bracket. If 2 persons positioning onto

bracket obtain rm grip at front and sides/base of boiler. Ensure co-

ordinated movements during 2 person lifts to ensure equal spread of
weight of load. If 1 person positioning onto bracket recommend obtain

rm grip supporting base of boiler. Ensure safe lifting techniques are

used – keep back straight – bend using legs - when lifting load from

oor level. Do not twist – reposition feet instead. Keep boiler as close

as possible to body throughout lift to minimise strain on back. Always
use assistance if required. Recommend wear suitable cut resistant
gloves with good grip to protect against sharp edges and ensure good

grip when handling appliance.

Positioning of Appliance for Final Installation
– in roof space restricting installation.

This appliance is deemed to be a one person lift when removed from
the carton. Obtain rm grip on front and sides of appliance, lift up­wards, ensure stable balance achieved and lift upwards to drop into

place onto bracket. If 2 persons positioning onto bracket obtain rm

grip at front and sides/base of boiler. Ensure co-ordinated movements
during 2 person lifts to ensure equal spread of weight of load. If 1
person positioning onto bracket recommend obtain rm grip support­ing base of boiler. Ensure safe lifting techniques are used - keep back

straight – bend using legs - when lifting load from oor level. Do not

twist – reposition feet instead. Keep boiler as close as possible to body
throughout lift to minimise strain on back. Always use assistance if re­quired. Recommend wear suitable cut resistant gloves with good grip
to protect against sharp edges and ensure good grip when handling
appliance. It is recommended a risk assessment of the roof space
area be carried out before moving the appliance into the area to take

into account access, stability of ooring, lighting and other factors, and

appropriate measures taken.

58

18 Declaration of Conformity

14506

59

Notes

60

Because of our constant endeavour for improvement, details may vary slightly from those shown in these instructions.

0020057279-02 02.08

Glow-worm, Nottingham Road, Belper, Derbyshire. DE56 1JT

0020057279