Saunier duval XEON 80FF User Manual

Instructions for Use

Installation and Servicing

To be left with the user

80ff

Fanned Flue Boiler

221972A.11.01

7336

(S.I.T.)

This is a Cat I2H Appliance

Reference in these instructions to British Standards and Statutory

Regulations/Requirements apply only to the United Kingdom.

The instructions consist of three parts, User, Installation and Servicing Instructions, which includes the Guarantee Registration

For Ireland the rules in force must be used.

Card. 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.

Guarantee Registration

Thank you for installing a new Saunier Duval appliance in your home.

Saunier Duval appliances' are manufactured to the very highest standard so we are pleased

to offer our customers' a Comprehensive First Year Guarantee.

In the center pages are to be found your Guarantee Registration Card, which we recommend you complete and

return as soon as possible.

If this card is missing you can obtain a copy or record your registration by telephoning the Heatcall Customer

Service number 01773 828100.

Our Guarantee gives you peace of mind plus valuable protection against breakdown by covering the cost of:

✔

All replacement parts

❏

✔

All labour charges

❏

All call-out charges

✔

❏

One Contact Local Service

REGISTER YOUR SAUNIER DUVAL APPLIANCE

FOR 1ST YEAR GUARANTEE PROTECTION

CALL 0208 247 9857

Customer Services:
Tel: [phone]
Fax: [phone]

Nottingham Road, Belper, Derbyshire. DE56 1JT

Tel: [phone] Fax: [phone]

Hepworth Heating Ltd.,

General/Sales enquiries:

Important Information

Testing and Certification

This boiler is tested and certificated for safety and performance. It is therefore important that no alteration is made to the boiler, without
permission, in writing, from Hepworth Heating Ltd.

Any alteration not approved by Hepworth Heating Ltd., could invalidate the certification, boiler warranty and may also infringe the current issue of
the Statutory Requirements, see Section 1.4.

CE Mark

This boiler meets the requirements of Statutory Instrument No. 3083 The boiler (Efficiency) Regulations, and therefore is deemed to meet the
requirements of Directive 92/42/EEC on the efficiency requirements for new hot water boilers fired with liquid or gaseous fuels.

Type test for purposes of Regulatioon 5 certified by: Notified body 0086.
Product/productioncertifiedby: Notified body 0086.

The CE mark on this appliance shows compliance with:

1. Directive 90/396/EEC on the approximation of the laws of the Member States relating to appliances burning gaseous fuels.

2. Directive 73/23/EEC on the harmonization of the Laws of the Member States relating to the 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.

INFORMATION FOR THE INSTALLER AND SERVICE ENGINEER.

Under Section 6 of The Health and Safety at Work Act 1974, we are required to provide information on substances hazardous to health.

CERAMIC FIBRE/INSULATION PADS.

These can cause irritation to skin, eyes and the respiratory tract. If you have a history of skin complaint you may be susceptible to irritation. High dust
levels are usual only if the material is broken. Normal handling should not cause discomfort, but follow normal good hygiene and wash your hands
before eating, drinking or going to the lavatory. If you do suffer irritation of the eyes or severe irritation to the skin seek medical attention.

THERMOSTATS

These contain very small amounts of xylene in the sealed phial and capillary. If broken, under normal circumstances the fluid does not cause a
problem, but in case of skin contact, wash with cold water. If swallowed drink plenty of water and seek medical attention.

CUT-OFF DEVICES

These contain activated charcoal and a very small amount of chlorodifluormethane in the sealed phial and capillary. If broken, under normal
circumstances the fluid does not cause a problem. If there is irritation to the eyes or skin then seek medical attention.

Spare Parts

REMEMBER, When replacing a part on this appliance, use only spare parts that you can be assured conform to the safety and
performance specification that we require. Do not use reconditioned or copy parts that have not been clearly authorised by Hepworth
Heating Ltd.

CONTENTS DESCRIPTION SECTION PAGE No.

INSTRUCTIONS

FOR USE

INSTALLATION
INSTRUCTIONS

Introduction 3
Lighting the Boiler 4

General Data 1 5
Flue & Ventilation 2 8
Water Systems 3 9
Flue and Appliance Preparation 4 13
Boiler Installation 5 18
Commissioning 6 22
Instructions to User 7 25

SERVICING

INSTRUCTIONS

221972A

Servicing 8 25
Fault Finding 9 27
Replacement Parts 10 33
Spare Parts 11 38

2

Instructions for Use

Introduction

WARNING. It is important that the case (not the controls tray)
is not disturbed or removed other than for servicing by a
competent person.

Please read these instructions and follow them carefully for the
safe and economical use of your boiler.

The Xeon ff series are fanned flue boilers designed to provide
central heating and indirect domestic hot water.

The boiler is fully automatic in operation having only one user
control, the control thermostat.

The Gas Safety (Installation and Use)
Regulations

In your interest and that of gas safety it is the law that ALL gas
appliances are installed by a competent person in accordance
with the above regulations.

Gas Leak or Fault

If a gas leak or fault exists or is suspected, the boiler must be
turned off, including the electrical supply and must not be used
until the fault has been put right.

Advice/help should be obtained from your installation/servicing
company or the local gas undertaking.

Electrical Supply Failure

Failure of the electrical supply will cause the burner to go out.
Should this occur, operation of the appliance will normally
resume after the electrical supply is restored.

If the boiler does not relight after an electrical supply failure the
overheat safety cutoff device may need resetting, remove the
controls cover and press the reset button, refer to diagram 1.

To obtain service, please call your installer or Heatcall (Saunier
Duval’s own Service Organisation) using the telephone number
given on the controls tray.

Please be advised that the ‘Benchmark’ logbook should be
completed by the installation engineer on completion of
commissioning and servicing.

All CORGI Registered Installers carry a CORGI ID card, and
have a registration number. Both should be recorded in your
boiler Logbook. You can check your installer is CORGI registered
by calling CORGI direct on :- 01256 372300.

Boiler Clearances

If fixtures are positioned close to the boiler space must be left
as shown in diagram 2. At least a minimum clearance of 500mm
must be left in front of the boiler to allow for servicing.

Boilers Installed in a Compartment or
Cupboard

If the boiler is installed in a compartment or cupboard do not
obstruct any ventilation openings.

Do not use the compartment or cupboard for storage.

CONTROLS COVER

4140

Overheat Safety Cutoff

If the overheat safety cutoff device operates on any other
occasion than an electrical supply failure, press the reset button
as in “Electrical Supply Failure”. If the overheat operates again,
turn the appliance off and contact your installation/servicing
company.

Maintenance

To ensure the continued efficient 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, but in general
once a year should be enough.

If this appliance is installed in a rented property there is a duty
or care imposed on the owner of the property by the current
issue of The Gas Safety (Installation and Use) Regulations,
Section 35.

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

4625

VIEWING WINDOW

SETTING POINT

RESET
BUTTON

CONTROL
THERMOSTAT
KNOB

DATA &
SERIAL
NUMBER
LABEL

GAS SERVICE
COCK (Shown
Off)

Diagram 1

3

221972A

Instructions for Use

Cleaning

WARNING. This appliance contains metal parts (components)
and care should be taken when handling and cleaning, with
particular regard to edges.

Clean the casing occasionally by wiping it over with a damp
cloth or dry polishing duster.

Do not use an abrasive cleaner.

Boiler Electrical Supply

WARNING. This boiler must be earthed.
The boiler must only be connected to a 230V~50Hz supply

protected by a 3A fuse.
All wiring must be in accordance with the current issue of

BS7671.
Wiring to the boiler must be PVC insulated type to the current

issue of BS6500 Table 16, not less than 0.75mm
The colours of three core flexible cable are:
Brown - live, Blue - neutral,
Green/yellow - earth.
As the markings on your plug may not correspond with these

colours continue as follows:
The cable coloured blue must be connected to the terminal

marked “N” or black.
The cable coloured brown must be connected to the terminal

marked “L” or red.
The cable coloured green/yellow must be connected to the

terminal marked “E”, or green or the earth symbol

500mm

Additional clearances may be
required for installation

100mm

65mm

FRONT

VIEW

2

(24/0.20mm).

.

SIDE OR
REAR FLUE
5mm

5mm

6mm6mm

0081N

To Light the Boiler

WARNING. Sealed Systems
A sealed water system must be filled and pressurised by a

competent person.
Only light the boiler when you are sure that the system has been

filled and pressurised.
The pressure gauge should show at least 0.7bar, anything less

than this figure could indicate a leak and you MUST contact your
installation/servicing company.

If there is any doubt about the boiler being full of water consult
your installation/servicing company.

ALL SYSTEMS.
Turn the electrical supply on to the boiler and check that all

remote controls are calling for heat.

To Turn the Boiler On

Remove the controls cover, by withdrawing it forward and off,
see diagram 1.

Turn the control thermostat knob clockwise to any position
between MIN and MAX. The maximum temperature setting is
about 82

o

C (180oF), see diagram 1.
The boiler lighting operation is now automatic as follows.
The fan operates, followed by an ignition spark until the pilot is

lit. When the pilot is alight the ignition system switches off and
the main burner lights. The flames can be seen through the
viewing window, see diagram 1.

The main burner will remain alight until switched off by the
control thermostat or any remote control.

If the boiler is switched OFF, by hand, wait at least 30 seconds
before switching on again.

When the boiler switches off, both the pilot and main burner go
out.

The automatic lighting sequence will operate again when heat
is required.

Refit the controls cover.
It should be noted that this is a fan flue appliance and fan

operation may be heard.

To Turn the Boiler Off

For short periods, turn the control thermostat knob anti-clockwise
to “O” Off. To relight, turn the control thermostat knob to any
position between “MIN” and “MAX”.

For longer periods, turn the control thermostat knob fully anti­clockwise to “O” Off and switch off the electrical supply to the
boiler.

To relight follow the lighting sequence given above.

Protection Against Freezing.

If the boiler is to be out of use for any long period of time during
severe weather conditions we recommend that the whole of the
system, including the boiler, be drained off to avoid the risk of
freezing up. Make sure that, if fitted, the immersion heater in the
cylinder is switched off.

For the position of the serial number, see diagram 1.

221972A

Diagram 2

4

1 General Data

B

PUMPED

AP

C

D

E

SIDE ELEVATION FRONT ELEVATION

MODEL A B C D E F G H J K L M N P

80ff 70 300 63 146 78 360 146 94 700 574 14 63 130 38

RETURN

WATER CONNECTIONS
22mm COPPER PIPE

GAS CONNECTIONS

1

RC

/2 (1/2 in. BSPT)

PUMPED

FLOW

F

G

H

C

L

J

L

N

K

7339

D

M

Important Notice

This boiler is for use only on G20 gas.
This boiler can be used on open vented or sealed water

systems.
When used on an open vented system domestic hot water can

only be provided by a pumped primary circulation.
Wherever possible, all material, appliances and components

used shall comply with requirements of applicable British
Standards.

Where no British Standards exist, materials and equipment
should be fit for their purpose and of suitable quality and
workmanship.

Sheet Metal Parts

WARNING. When installing or servicing this boiler care should
be taken when handling sheet metal parts, to avoid any possibility
of personal injury.

Diagram 1.1

1.1 Statutory Requirements

The installation of the boiler must be carried out by a competent
person in accordance with the relevant requirements of the
current issue of:-

The manufacturer’s instructions, supplied.
The Gas Safety (Installation and Use) Regulations, The Building

Regulations, Local Water Company Byelaws, The Health and
Safety at Work Act, Control of Substances Hazardous to
Health, The Electricity at Work Regulations and any local
regulations which may apply.

Detailed recommendations are contained in the current issue of
the following British Standards and Codes of Practice:-

BS4814, BS6798, BS5440 Part 1 and 2, BS5546 Part 1,
BS5449, BS6891, BS6700, BS7074 Part 1 and 2, BS7593,
BS7671.

Manufacturer’s instructions must not be taken as overriding
statutory requirements

5

221972A

1 General Data

DATA TABLE 1.
MODEL
TOTAL DRY

WEIGHT
(Including
Terminal)

LIFT
WEIGHT

WATER
CONTENT

GAS
CONNECTION

ELECTRICITY
RATING

WATER

Internal fuse F1 & F2 (F1A)
2x22mm copper pipes from

CONNECTION
ELECTRICITY

SUPPLY
DATA LABEL

Bottom right hand side of case

APPROX. m3/h
GAS
RATE ft3/h

80ff

51 kg (112 lb)

45.3 kg (100lb)

3.35 litre (0.74 gallon)

Rc 1/2 in.

71W

top of case

230V~50Hz, fused 3A

Min. Medium Max.

2.36 2.51 2.67
83 89 94

On completion test the gas installation for soundness using the
pressure drop method and suitable leak detection fluid, purge
in accordance with the above standard.

1.6 Electrical Supply

WARNING. This boiler must be earthed.
All system components shall be of an approved type and shall

be connected in accordance with the current issue of BS7671
and any applicable local regulations.

Connection of the boiler and system controls to the mains
supply must be through a common isolator and must be fused
3A, maximum. This method of connection must be by a fused
double pole isolating switch, with a minimum contact separation
of 3mm on both poles. The switch should be readily accessible
and preferably adjacent to the appliance. It should supply the
appliance only and be easily identifiable as so doing.

Alternatively, an unswitched shuttered socket outlet and 3A
fused 3 pin plug, both to the current issue of BS1363 may be
used provided that they are not used in a room containing a bath
or shower.

Wiring to the boiler must be to the current issue of BS6500 Table
16, not less than 0.75mm

2

(24/0.20mm).

1.7 Contents of Packaging

The boiler is delivered in one pack, refer to Section 4.1 for
contents.

1.8 Water System

This boiler may be fitted to an open vented or a sealed water
system.

1.2 Data

See Table 1 and diagram 1.1.
All dimensions are given in millimetres (except as noted).
The Seasonal Efficiency Domestic Boilers UK (SEDBUK)

is 79.4%.
The value is used in the UK Government’s Standard Assessment

Procedure (SAP) for energy rating of dwellings. The test data
from which it has been calculated have been certified by B.S.I.

1.3 Range Rating

This boiler is range rated and may be adjusted to suit individual
system requirements.

See diagram 1.2 for the ratings and settings.

1.4 Testing and Certification

This boiler is tested and certificated for safety and performance.
It is, therefore, important that no alteration is made to this boiler
unless approved, in writing, by Hepworth Heating Ltd.

Any alteration not approved by Hepworth Heating Ltd., could
invalidate certification, boiler warranty and could also infringe
the statutory requirements.

1.5 Gas Supply

The gas installation shall be in accordance with the current
issue of BS6891.

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.

9946

Diagram 1.2

221972A

6

1 General Data

1.9 Drain

System
A drain tap must be provided at the lowest points of the system

which will allow the entire system, boiler and hot water cylinder
be drained.

Draining taps should be to the current issue of BS2879.
Boiler
A draining point is fitted at the bottom right hand side of the heat

exchanger.
Cover controls to avoid water damage.
If required remove the combustion chamber front cover to

improve access.

1.10 Safety Valve

A safety valve need not be fitted to an open vented system.

1.11 Location

This boiler is not suitable for outdoor installation.
This boiler may be installed in any room, although particular

attention is drawn to the requirements of the current issue of
BS7671 with respect to the installation of a boiler in a room
containing a bath or shower. The electrical provisions of the
Building Standards (Scotland) apply to such installations in
Scotland.

The boiler must be mounted on a flat wall which is sufficiently
robust to take its total weight.

The boiler may be fitted to a wall made of combustible material.

1.12 Boiler Clearances

Refer to diagram 1.3.
This boiler must be positioned so that at least the minimum

operational and servicing clearances are provided.
Additional clearances may be required for installation.
If fixtures are positioned next to the boiler they should be made

removable for access to pipework.
At least a minimum of 500mm clearance must be left in front of

the boiler for servicing, see diagram 1.3.

1.13 Room Ventilation

The boiler is room sealed and does not require the room or
space containing it to have permanent air vents.

1.14 Boilers in a Compartment

Where the installation of the boiler will be in an unusual position,
special requirements are needed, the current issue of BS6798
gives detailed guidance on these requirements.

A compartment used to enclose the boiler must be designed
and constructed specifically for this purpose. An existing
cupboard or compartment modified for the purpose may be
used. Details of essential requirements for cupboard or
compartment design are given in the current issue of BS6798.

The doorway opening should be of sufficient size to allow for
easy removal of the boiler.

Where the boiler is fitted in a cupboard or compartment,
permanent high and low level ventilation must be provided. The
minimum ventilation areas required are given in Table 2.

1.15 Timber Frame Building

If the boiler is to be installed in a timber frame building it should
be fitted in accordance with the Institute of Gas Engineers

500mm

Additional clearances may be
required for installation

5mm

6mm6mm

SIDE OR
REAR FLUE
5mm

100mm

65mm

FRONT

VIEW

MINIMUM CLEARANCES FROM WALLS
CEILING, FLOOR, CUPBOARD, WORKTOPS,
AND INFLAMMABLE MATERIALS

Diagram 1.3

TABLE 2. COMPARTMENT AIR VENTS

VENTILATION HIGH LEVEL LOW LEVEL
REQUIREMENTS VENT AREA VENT AREA

2

cm

VENTILATION

264 41 264 41

FROM ROOM
OR SPACE

264 41 264 41

VENTILATION

132 21 132 21

FROM
OUTSIDE

132 21 132 21

document IGE/UP/7/1998. If in doubt seek advice from the local
gas undertaking or Hepworth Heating Ltd.

2

in

cm

2

1.16 Heating System Controls

The heating system should have installed: a programmer and
room thermostat controlling the boiler.

Thermostatic radiator valves may be installed, however they
must not be fitted in a room where a room thermostat is located.

Note: For further information, see The Building Regulations
1991 - Conservation of fuel and power, 1995 edition - Appendix
G, table 4b.

7

0081N

2

in

221972A

2 Flue and Ventilation

Note. Detailed recommendations for flue are given in the
current issue of BS5440 Part 1.

2.1 Terminal Position

The minimum acceptable siting dimensions for the terminal
from obstructions, other terminals and ventilation openings are
shown in diagram 2.1.

The terminal must be exposed to the external air, the position
allowing free passage of air across it at all times.

Car ports 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 it is made of plastic sheeting. If the car port
consists of a roof and two or more walls, seek advice from the
local gas company before installing the boiler.

If the terminal is fitted within 600mm below plastic guttering or
painted soffit an aluminium shield 1500mm long should be fitted
immediately beneath the guttering or eaves. If the terminal is
fitted within 450mm below painted eaves or a painted gutter, an
aluminium shield 750mm long should be fitted immediately
beneath the guttering or eaves.

2.2 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
a minimum of 50mm clearance from any part of the terminal and
be central over the terminal.

A suitable guard, reference Type “K3”, can be obtained from:

Tower Flue Components Ltd
Morley Road
Tonbridge
Kent
TN9 1RA

D

F

MINIMUM
SPACING

C

K

L

K

G

in mm

L

A

B,C

A

F

G

Under Car Port etc.

G

M

A

E

G

F

G

H,I

MINIMUM SITING DIMENSIONS
FOR FANNED FLUE
TERMINALS POSITION

B,C

K

F

J

K

A DIRECTLY BELOW, ABOVE OR

HORIZONTALLY TO AN OPENING,
AIR BRICK, OPENING WINDOWS,
AIR VENT OR ANY OTHER
VENTILATION OPENING. 300

B BELOW GUTTER, DRAIN/SOIL PIPE 75
C BELOW EAVES 200
D BELOW A BALCONY OR CAR PORT 200

E FROM VERTICAL DRAIN PIPES AND

SOIL PIPES 75

F FROM EXTERNAL CORNERS 300
G ABOVE ADJACENT GROUND OR

BALCONY LEVEL 300

H FROM A SURFACE FACING THE

TERMINAL 600

I FACING TERMINALS 1200

J FROM OPENING (DOOR/WINDOW) IN

CAR PORT INTO DWELLING 1200
K VERTICAL FROM A TERMINAL 1500
L HORIZONTALLY FROM A TERMINAL 300

M FROM INTERNAL CORNERS 25

0103M

221972A

0161M

Diagram 2.1

8

3 Water Systems

The installation of the boiler must comply with the requirements
of the current issue of BS6798.

3.1 Frost Protection

If the position of the boiler is such that it may be vulnerable to
freezing it should be protected as specified in the current issue
of BS5422. It is recommended that a frost protection thermostat
be fitted.

3.2 Pump

The pump, with integral valves, should be fitted in the heating
flow pipework from the boiler, it should be set to produce a
temperature difference of 11oC (20oF) between the flow and
return, with the boiler thermostat set at “MAX”, which is about
82oC (180oF).

The pressure loss of the boiler can be found from diagram 3.1.
High resistance microbore systems may require a higher duty

pump.

3.3 Bypass - Fully Pumped and Sealed Water
System

A bypass is usually unnecessary on systems using a 3 port
diverter valve since one port will remain in the open position at
all times. This allows satisfactory operation of the pump
overrun.

However if thermostatic radiator valves are fitted to all radiators
or two port valves are used a bypass is required.

The bypass connection must be at least 2.5 metres away from
the boiler.

The flow through the boiler must not be allowed to fall such that
there is a temperature difference greater than 20
flow and return.

3.4 Water System

For an open vented system the boiler must be supplied from an
unrestricted water supply taken from a feed and expansion
cistern fitted at a maximum height of 27metres above the boiler.

The cold feed must be 15mm minimum size.
It is important that the relative positions of the pump, cold feed

and open vent are as shown in diagram 3.2.
The unrestricted open vent from the boiler must rise continuously

to discharge over the feed and expansion cistern.

3.5 Domestic Hot Water System

General. The domestic hot water service must be in accordance
with the current issue of BS5546, refer also to the current issue
of BS6700.

o

C between the

1000

750

500

(mm head of water)

Water pressure loss

250

0

051015 20 25 30

Design Flow Rate

Flow rate (litres/minute)

30.6

litre/min

PRESSURE LOSS
OF BOILER

Diagram 3.1

3.8 Inhibitor

Attention is drawn to the current issue of BS5449 and BS7593
on the use of inhibitors in central heating systems.

If an inhibitor is to be used, contact a manufacturer or Hepworth
Heating Ltd., for their recommendations as to the best product
to use.

When installing in an existing system take special care to drain
the entire system, including radiators, then thoroughly cleaning
out before installing the boiler whether or not adding an inhibitor.

3.9 Sealed Water Systems

The installation should comply with the appropriate requirements
of the current issue of BS4841, BS5449, BS6759, BS6798 and
BS7074 Part 1 and 2, see diagram 3.4 for suggested layout.

3.10 Safety Valve

A safety valve must be fitted to a sealed water system.
It shall be preset, nonadjustable with a lift pressure of 3bar,

incorporating seating of a resilient material, a test device and a
connection for drain.

The drain from the safety valve must be routed clear of any
electrical fittings and positioned so that any discharge can be
seen.

0088(a)M

3.6 Cylinder

For all systems supplying domestic hot water the cylinder must
be indirect. It is recommended that the cylinder be fitted with
some form of temperature control.

3.7 Fully Pumped Domestic Hot Water

The connection for this type of system MUST be as shown in
diagram 3.2 and 3.3.

9

221972A

3 Water Systems

OPEN VENTED FULLY PUMPED WATER SYSTEM
RECOMMENDED RELATIONSHIP BETWEEN
PUMP COLD FEED AND VENT

22mm VENT

PUMP

150mm
MAX.

(MIN.)

15mm (MINIMUM)
COLD FEED

RETURN

CYLINDER

FLOW

450mm
MIN.
HEIGHT

FEED AND
EXPANSION
CISTERN

1150mm
MIN.

6458

FLOW

HEATING

4114

FLOW

RETURN

28mm
PIPE

22 X 28
UNION
CONNECTION

22mm VENT & 15mm COLD FEED
TO BE FITTED IN ACCORDANCE
WITH BS 5449

6462

RET.

BOILER

IF REQUIRED
22mm (MINIMUM)
BY-PASS WITH
LOCKSHIELD VALVE

Diagram 3.2

3.11 Expansion Vessel

A diaphragm type expansion vessel, conforming to the current
issue of BS4814 (see also BS7404 Part 1 and 2) must be
connected at a point close to the inlet side of the circulating
pump, see diagram 3.4 unless laid down differently by the
manufacturer.

The expansion vessel volume depends upon the total water
system volume and the initial system design pressure. For any
system an accurate calculation of the vessel size is given in the
current issue of BS7074 Part 1.

Example. For an initial system design pressure of 0.7bar the
minimum total vessel volume required is 0.063xTotal 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.

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.

The water content of the boiler is given in Data Table 1.

3.12 Pressure Gauge

A pressure gauge with a set pointer and covering at least the
range 0 to 4bar (0 to 60lb/in2) shall be permanently fitted to the
system in a position where it can be seen when filling the
system.

1metre Min.

27 metres

Max.

FULLY PUMPED CIRCULATION
SYSTEM (DIAGRAMMATIC)

1metre Min.

IF REQUIRED
BYPASS 22mm
MIN WITH
LOCKSHIELD
VALVE

PUMP

22mm FOR COMBINED FEED & VENT
TO BE FITTED IN ACCORDANCE
WITH BS 5449

IF REQUIRED

27 metres

Max.

FULLY PUMPED CIRCULATION
BYPASS (DIAGRAMMATIC)

BYPASS 22mm
MIN WITH
LOCKSHIELD
VALVE

PUMP

INDIRECT
CYLINDER

ALTERNATIVE
SYSTEM
CONTROL
VALVES

HEATING
SYSTEM

6463

INDIRECT
CYLINDER

HEATING
SYSTEM

ALTERNATIVE
SYSTEM
CONTROL
VALVES

Diagram 3.3

221972A

10

3 Water Systems

(Make-up
alternatives)

3 LITRES (0.66 gals)
MAKE-UP BOTTLE
(if required)

NON-RETURN
VALVE

HEATING

CIRCUIT

AUTO
AIR
VENT

FLOW

RETURN

DRAIN
COCK

BOILER

IF REQUIRED
22mm (min)
BY-PASS WITH
LOCKSHIELD
VALVE

SAFETY
VALVE

AIR
RELEASE
POINT

FILLING POINT

CIRCULATING
PUMP

PRESSURE
GAUGE

EXPANSION
VESSEL

6465

METHOD 1

TEMPORARY
HOSE

SUPPLY
PIPE

METHOD 2

TEMPORARY
HOSE

SUPPLY
PIPE

METHOD 3

CISTERN

HOSE
UNIONS

SUPPLY STOP
VALVE

DOUBLE CHECK
VALVE ASSEMBLY

HOSE
UNIONS

SUPPLY STOP
VALVE

OVERFLOW

SERVICING
VALVE

COMBINED
CHECK VALVE
AND VACUUM
BREAKER

SERVICING
VALVE

SERVICING
VALVE

PRESSURE
REDUCING
VALVE

0051M

HEATING
SYSTEM

HEATING
SYSTEM

HEATING
SYSTEM

Diagram 3.4

3.13 Domestic Hot Water Cylinder

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

It must be suitable for working at a gauge pressure of 0.35bar
above the safety valve setting.

3.14 Domestic Hot Water System - Unvented

Where a storage system will not have a vent to atmosphere the
installation must comply with Building Regulations and local
Water Company Bye-laws, see also the current issue of BS6700.

If fitting into an existing system the local authority must also be
advised.

3.15 Filling a Sealed Water System

Provision for filling the system at low level must be made. Three
methods are shown in diagram 3.5. There must be no permanent
connection to the mains water supply, even through a non­return valve.

3.16 Water Makeup

Provision must be made for replacing water lost from the
system. A make up vessel mounted above the highest point of
the system and connected through a non-return valve to the
system on the return side of either the hot water cylinder or
heating system, see diagram 3.4.

Alternatively provision for make up can be made by a filling loop.

SUPPLY
STOP VALVE

SUPPLY
PIPE

HOSE
UNIONS

DOUBLE CHECK
VALVE ASSEMBLY

Diagram 3.5

11

221972A

4 Flue and Appliance Preparation

4.1 Unpacking

Open the carton, check the items supplied against the boiler
pack contents list on the flap, see diagram 4.1.

4.2 Flue Position and Length

Determine flue application, length and terminal position before
starting.

Refer to diagram 4.2 or 4.3.
If you are using a Flue Bend or a Vertical Flue Kit, please follow

the instructions supplied with that kit.
To make a neat finish to the flue outlet a flue collar kit, part No.

459248, with instructions, is available.
The use of this collar will mean that the flue lengths will need to

be altered, full instructions are given in the kit.
Note: If required, an optional Wall Sleeve Kit, part No.900864,

is available, complete with fixing instructions.

4.3 Flue Preparation

All flue assemblies are designed for internal installation (optional
wall liner is required), given that there is sufficient clearances
opposite to the flue for the installation of the flue.

LOOSE

ITEMS PACK
WALL
TEMPLATE

4791

If there is insufficient clearance the flue can be installed from
outside.

For a wall thickness up to 300mm, provided that there is
sufficient space and the optional wall liner kit is used the flue can
be fully installed from the inside.

6827

Standard Flue terminal illustrated.

REAR FLUE LENGTHS

Distance R = Wall thickness

STD. 75mm to 505mm

MOUNTING
BRACKET

CARTON
TOP

INSTRUCTIONS

BOILER

1M 75mm to 1015mm
2M 75mm to 2015mm
3M 75mm to 2995mm

Diagram 4.2

6828

Standard Flue terminal illustrated.

SIDE FLUE LENGTHS

Distance S = External wall face to boiler case

221972A

Diagram 4.1

STD. 81mm to 513mm
1M 81mm to 1023mm
2M 81mm to 2023mm
3M 81mm to 3003mm

Diagram 4.3

12

4 Flue and Appliance Preparation

SIDE FLUE

REAR FLUE

75mm

115mm
MINIMUM
HOLE

0098M

BOILER
CENTRE LINE

FLUE
CENTRE LINE

14mm

For a wall thickness of over 300mm the external flue hole will
need to be made good from the outside. This applies also if you
use the flue kit without the optional kit, irrespective of wall
thickness.

4.4 Rear and Side Flue Application

Select the boiler location and flue application, with due regard
to the terminal position.

Take the template from the boiler pack and temporarily position
it on the wall, making sure that the minimum clearances are
maintained, see diagram 1.2.

For a rear flue mark the position of the flue as diagram 4.4.
For a side flue, extend the centre line horizontally left or right to

the corner adjacent surface where the flue is required to exit to
outside. Mark the position of the centre of the flue and boiler,
see diagram 4.4.

4.5 Flue Hole Cutting

Having marked out the flue centre cut a hole for the flue using,
preferably, a 115mm minimum core drill.

4.6 Wall Mounting Bracket

Reposition the template, making sure of dimensional alignment
with the flue hole.

Mark the boiler fixing points and mounting bracket position, see
diagram 4.5.

Drill holes and plug, to suit No.12x2in woodscrews, fit the
screws allowing sufficient clearance, about 5mm, to accept the
swing brackets, see diagram 4.5.

Secure the mounting bracket to the wall with No.12x2in
woodscrews and plugs, see diagram 4.5.

Diagram 4.4

TEMPLATE

BOILER
CENTRELINE

7 dia.

7 dia.

3

/16 in dia.

PLUG

TOP BOILER
MOUNTING
HOLES

FLUE
CENTRELINE

MOUNTING
BRACKET FIXING
POINTS

3

/16 in dia.

PLUG

NO.
12x2in

NO.
12x2in

BOILER
CENTRELINE

5mm

FLUE
CENTRELINE

BOILER
MOUNTING
BRACKET

4096

13

Diagram 4.5

221972A

4 Flue and Appliance Preparation

4.7 Flue Duct

Mark the duct to the length required, this length allows for
expansion, see diagram 4.6 for rear flue and diagram 4.7 for
side flue, then cut square and remove any burrs.

4.8 Air Duct/Terminal

Mark the duct length, see diagram 4.8 for rear flue and diagram

4.9 for side flue, then cut square and remove any burrs.

4.9 Air Duct/Terminal and Flue Duct Assembly

Locate the flue duct into the air duct/terminal, see diagram 4.10.
Take the flue manifold from the loose items pack together with

the sealant. Place the sealant onto the flue manifold.
Fully locate the flue manifold in to the air duct/terminal and flue

duct assembly as shown in diagram 4.10, make sure the correct
alignment of the “Top”s.

Drill two 3mm diameter holes through the air duct/terminal to the
flue manifold secure with the two self tapping screws supplied
in the loose items pack.

It should now not be possible to remove the manifold.

6831

T MINUS 188mm

BOILER

CENTRE

LINE

6833

FLUE

DUCT

Diagram 4.7

6829

LONG FLUE

TERMINAL

STANDARD FLUE
TERMINAL

Q

Q PLUS 5mm

Q

221972A

Diagram 4.6

Diagram 4.8

14

4 Flue and Appliance Preparation

4.10 Rear Fitting

Fit the self adhesive foam seal provided in the flue pack around
the air duct/terminal at the position shown in diagram 4.13.

4.11 Side Fitting

Fit the self adhesive foam seal around the air duct/terminal such
that, when installed, the seal will be within the wall, see diagram

4.14.
If dimension "A" is greater than 75mm from the wall, the self

adhesive foam seal can be dispensed with, and the area around
the flue made good in the normal way, see diagram 4.14.

Important: If the wall liner kit is used the self adhesive foam seal
included in the wall liner kit must be used in place of the one
supplied with the flue pack, see diagram 4.11 for position of self
adhesive seal.

4616

6830

LONG FLUE

TERMINAL

BOILER

CENTRE

LINE

AIR DUCT/TERMINAL
AND FLUE DUCT
ASSEMBLY

STANDARD
FLUE
TERMINAL

Diagram 4.9

15

Diagram 4.10

221972A

4 Flue and Appliance Preparation

4.12 Flue Assembly - Installation

If the boiler is not to be fitted for some time cover the hole in the
wall.

On limited access installations push the flue assembly into and
through the hole such that it is within the wall and does not stick
out into the room, see diagram 4.12. Do not push the flue
assembly too far into the holes as it has to be pulled back into
the boiler and secured.

4.13 Internal Access Flue

If access to the outside wall is not practical, the flue system can
be installed from inside. Use of the optional wall liner kit is
required.

4082

GASKET

(PRE-ATTACHED)

Diagram 4.12

WITH WALL LINER KIT ONLY

FOAM

SEAL

10mm

WALL THICKNESS­UP TO 300mm

FOAM

SEAL

FOAM

SEAL

6832

Q

REAR FITTING

Diagram 4.13

6930

"A"

6931

WALL THICKNESS­OVER 300mm

221972A

Q-25mm

Q

Diagram 4.11

SIDE FITTING

16

FOAM

SEAL

Diagram 4.14

5 Boiler Installation

5 Boiler Preparation

With the boiler still in the bottom tray, slide the controls tray
upwards and remove it as shown in diagram 5.1.

Remove the front cover by undoing (and keeping) the screw and
wing nuts and lifting the front cover off, see diagram 5.1.

Remove the packing piece from inside the front cover.
Place front cover on one side until required.
Fit suitable compression fittings to the boiler connections.

5.2 Mounting the Boiler

As necessary, fit the blanking plate, see diagram 5.2.
Now make sure that the top, swing brackets are UPRIGHT.
Lift the boiler into position, hooking over the mounting bracket.
Swing the brackets over the two screws at the top. Hold the

swing bracket(s) in place whilst tightening the screw(s) on to it,
see diagram 5.3.

Remove the blue and red electrical connections from the fan,
see diagram 5.4.

Break the air pressure switch tube connections, see diagram

5.4.
Remove the fan assembly by removing the screws at the front,

slackening the screws at the rear and sliding it out, see diagram

5.4. Taking care not to damage the gasket.
Secure the flue assembly to the boiler using the previously fitted

dogpoint screws noting that these are keyhole fixings, see
diagram 5.5.

Make sure of the correct fitting of the flue to the boiler.
For a side outlet cut the fan duct extension to the length

required, see diagram 5.6.
Remove any burrs and fit as diagram 5.6.
Fit the fan duct extension to the elbow and assembly to the fan,

see diagram 5.6
Do not secure at this point with the screw.
Position the fan assembly and engage the fan duct extension

over the flue manifold. Make sure, by pushing in the flue duct
extension that a secure seal is made. Mark the final position of
the fan duct extension in the screw hole on the elbow, remove
the assembly, seal with sealant, supplied in the loose items
pack and secure with the screw as diagram 5.6.

Secure the elbow to the fan outlet with the Jubilee clip.
For rear outlet cut and fit the fan duct extension as shown in

diagram 5.6.
Fit fan assembly by engaging the fan duct extension over the

flue manifold spigot, see diagram 5.7.
Secure the fan assembly with the screws previously slackened

and removed.
Reconnect the blue and red electrical connections to the fan,

the polarity of the connections is not important.
Reconnect the air pressure switch tubes as shown in diagram

5.4.

WING
NUT

NUT(3)

GASKET

CONTROLS
COVER

FRONT
COVER

NUT

SHAKEPROOF
WASHER

Diagram 5.1

BLANKING
PLATE

4115

4617

17

Diagram 5.2

221972A

5 Boiler Installation

5.3 Water Circulation System

Complete the water connections to the boiler.
Fill, vent and flush the system.
Check for any water leaks and put right.

5.4 Safety Valve Discharge

Fit a suitable discharge pipe to the safety valve and route it to
outside the building so that any discharge can be seen but will
not cause injury to persons, damage to property or any electrical
installation.

5.5 Gas Connection

Make the gas connection to the Rc1/2in gas service cock, see
diagram 6.1.

Check for leaks using a suitable leak detection fluid.

5.6 Control Box Removal

Remove the electrical control box securing screws, see diagram

5.8. Slide the box forwards and release, hook it onto the lip
bracket at the front, see diagram 5.8.

ELECTRICAL
CONNECTIONS

REAR SECURING SCREW (2)
(SLACKEN but do not remove)

AIR PRESSURE TUBES

CLEAR

RED

4086

SWING
BRACKET

SECURING
SCREWS (2)

NOTE:

PIPES REMOVED
FOR CLARITY

5mm

MOUNTING
BRACKET

Diagram 5.3

0167(a)M

GASKET

4134

SECURING
SCREW (2)

Diagram 5.4

LOCATION
LUG

KEYHOLE

Diagram 5.5

221972A

18

5 Boiler Installation

REAR

SIDE
LEFT

FAN
DUCT
EXTENSION

JUBILEE
CLIP

SIDE
RIGHT

FAN

DUCT

EXTENSION

2.5mm
dia.drill

LEFT

RIGHT

REAR

VERTICAL

SCREW

(2)

4089

FLUE ELBOW

5.7 Electrical Connection

WARNING. This boiler must be earthed.
Take care not to damage any internal wiring and capillaries.
Take plastic cable retaining clip, from the loose items pack, peel

off the backing paper and position it in a suitable place to secure
the incoming cable.

Using heat resistant (to 85

0.2mm) to the current issue of BS6500 Table 16 and of suitable
length, thread through cable clamps, secure into the plastic
clips and connect to appropriate terminals, see diagram 5.9 and

9.5.
Standard colours are, brown - live (L), blue - neutral (N) and

green and yellow - earth (E).
The mains cable outer insulation must not be cut back external

to the cable clamp.
Make sure the cable is suitably secured.
When making connections, make sure that the earth conductor

is made of a greater length than the current carrying conductors,
so that if the cable is strained the earth conductor would be the
last to become disconnected.

o

C) cable of at least 0.75mm2 (24/

Cutting 'MARK' lengths.
Lefthand flue does not require cutting.

(REAR FLUE OUTLET ILLUSTRATED)

FLUE
MANIFOLD
SPIGOT

FAN DUCT
EXTENSION

Diagram 5.6

4093

5.8 Pump Connection

The pump must be connected directly to the control box, as
shown in diagram 5.9 threading the cable through the cable
clamp in the side of the control box.

5.9 External Controls

Any external controls must only be wired to interrupt the red link
between terminals SL and 9.

19

Diagram 5.7

221972A

5 Boiler Installation

Make sure that the supply cable and all external cables are
secured and away from hot surfaces.

5.10 Testing

Checks to ensure electrical safety must be carried out by a
competent person.

After installation of the system, preliminary electrical system
checks as below should be carried out.

1. Test insulation resistance to earth.

2. Test continuity and short circuit of all cables,

3. Test the polarity of the mains.
The installer is requested to advise and give guidance to the

user on the controls scheme used with the boiler.

FIXING SCREWS

4619

LIP BRACKET

4620

IGNITION
LEAD

PUMP
CABLE

CABLE
CLAMPS

MAINS
CABLE

Remove red link between 9 & SL when fitting
a time control etc (if no switch is fitted, link will
make the circulation pump run constantly).

3310

221972A

Diagram 5.10

20

6 Commissioning

Please ensure the “Benchmark” logbook is completed and left
with the user.

6.1 All Systems

Commissioning should be carried out by a competent person in
accordance with the current issue of BS6798.

Make sure that the system has been thoroughly flushed out with
cold water without the pump in place.

Refit the pump, fill the system with water, making sure that all
air is properly vented from the system and pump.

Before operating the boiler check that all external controls are
calling for heat.

6.2 Sealed Water Systems Only

Flush the whole of the system with cold water without the pump
in place. Refit the pump and fill until the pressure gauge
registers 2.7bar (40lbf/in2). Clear any air locks and check for
water soundness.

Check the operation of the safety valve, by allowing the water
pressure to rise until the valve opens. The valve should open
within +/-0.3bar (+/-4.3lbf/in
this is not possible conduct a manual check and test.

Release cold water to initial system design pressure.
The set pointer on the pressure gauge should be set to coincide

with the indicating pointer.

2

) of the preset pressure. Where

SETTING
POINT

GAS
PRESSURE
ADJUSTMENT
SCREW

OVERHEAT
SAFETY
CUT-OFF

CONTROL
THERMOSTAT
KNOB

GAS SERVICE COCK
(SHOWN OFF)

Diagram 6.1

PLASTIC
COVER

4085

4108

6.3 Initial Lighting and Testing

CAUTION. This work must be carried out by a competent
person, in accordance with the current issue of BS6798.

Make sure that all naked lights and cigarettes are out.
Identify the controls by reference to diagram 6.1.
Check that the boiler is isolated from the electrical supply.
Makes sure that the control thermostat is turned to “O” the “Off”

position.
Turn the gas service cock “On”, see diagram 6.1.
Test the pilot supply tube and its connections for gas soundness

as follows:
Disconnect the ignition lead from the PCB, see diagram 5.9.
Remove the combustion chamber front, see diagram 6.3.
WARNING. The fan operates on mains voltage, terminals will

become live.
Turn the electrical supply on and check that all remote controls

are calling for heat.
Check that the pump is circulating water through the system.
To complete the test it is necessary to operate the boiler without

its case, but UNDER ALL OTHER CIRCUMSTANCES the case
must be correctly fitted and sealed.

Turn the control thermostat knob fully clockwise and the fan will
work.

Note. There will be no sparks at the pilot. Take care and light
the pilot with a match.

Test the pilot supply and connections for gas soundness, using
a suitable leak detection fluid.

Very cold weather may delay the operating sequence.
The pilot rate is preset and must not be adjusted. The step

adjustment screw must not be touched.

MULTI­FUNCTIONAL
CONTROL

MAIN
BURNER

NOTE:

DO NOT ADJUST ANY
OTHER SETTING SCREWS

The pilot flame length should be as shown in diagram 6.4.
Turn the control thermostat knob to “O” and isolate the boiler

from the electrical supply.
Fit the combustion chamber front.
Reconnect the ignition lead to the PCB.

PRESSURE
TEST SCREW

Diagram 6.2

21

221972A

6 Commissioning

Stick the self adhesive arrow indicator to the data label, against
the rating that the boiler is going to be set to, for future reference.
The arrow is in the loose items pack.

Loosen the main burner pressure test point screw and connect
a suitable pressure gauge, see diagram 6.2.

Make sure that any remote controls are calling for heat.
Switch on/connect the electrical supply to the boiler and heating

system, neon 1 will light.

6.4 Testing - Electrical

Turn the boiler thermostat knob fully clockwise to the maximum
setting, which is about 82oC (180oF), neon 2 will light.

The lighting sequence is automatic as follows:
The fan operates
The spark ignition operates
The pilot solenoid opens

4138

SECURING
SCREW (4)

VIEWING
WINDOW

The pilot burner lights
The ignition spark stops
The main solenoid opens

and after a short period of time the main burner will light, look
through viewing window, see diagram 6.3.

Very cold weather may delay the operating sequence.

1. With the main burner alight, turn the gas service cock “Off”,
see diagram 6.1.

After a short period the main burner and pilot will go out.

2. The correct working of the flame supervision device is shown
by neon 4 going out within 10 seconds and the ignition starting
up.

Neons 1, 2 and 3 should stay alight.

3. If the above does not happen, refer to fault finding Section

9.1.

4. To carry on turn gas service cock “On” see diagram 6.1.
When the boiler switches “Off”, both the pilot and main burner

go out. The automatic lighting sequence will work again when
heat is required.

If an external control switches the boiler off, the pump will run on
for several minutes.

4146

NOTE:

PILOT SHIELD
REMOVED FOR
CLARITY

Diagram 6.3

10 to 20mm FLAME LENGTH

SPARK GAP
2 to 4mm

6.5 Testing - Gas

With the boiler on proceed as follows:­Test for gas soundness around the boiler gas components

using a suitable leak detection fluid, in accordance with the
current issue of BS6891.

Check the main burner gas pressure at least 10 minutes after
the boiler has lit, refer to Data Label.

If necessary adjust the gas pressure to obtain the required
setting turning screw clockwise, to decrease pressure, see
diagram 6.2.

Should any doubt exist about the gas rate, check it using the gas
meter test dial and stop watch, at least 10 minutes after the
burner has lit, making sure that all gas burning appliances and
pilot lights are off.

221972A

22

4139

Diagram 6.4

6 Commissioning

Turn the control thermostat knob fully anticlockwise to “O”.
Remove the pressure gauge from the test point and refit screw,
making sure a gas tight seal is made.

When the control thermostat is turned to the “Off” position, by
hand, wait at least 30 seconds before turning “On” again.

There may be an initial smell given off from the boiler when new,
this is quite normal and it will disappear after a short period of
time.

Refit the electrical controls box, see diagram 5.8.
Note. The neon indicator lights on the printed circuit board are

an aid to fault finding, for details refer to Section 9.

6.6 Testing - Open Vented

Allow the system to reach maximum working temperature and
examine for water leaks.

There should be no undue noise in the system and no pumping
over of water or entry of air at the open vent above the feed and
expansion cistern.

All systems - The boiler should be turned off and the system
drained off as rapidly as possible, whilst still hot.

6.7 Adjustment - Fully Pumped Open Vented
and Sealed Water Systems

When commissioning the system the boiler should first be fired
with the bypass fully closed on full service, that is, central
heating and domestic hot water. Adjust the pump to the system
design setting then balance the system. Having achieved a
satisfactory condition operate the boiler with the bypass fully
closed on minimum load, normally this will be central heating
only with one radiator in the main living area operating. The
bypass valve should be gradually opened to achieve a
temperature difference no greater than 20oC between the flow
and return.

UNDER NO CIRCUMSTANCES SHOULD THIS VALVE BE
LEFT IN THE FULLY CLOSED POSITION.

WING
NUT

TOP
SEAL

SIDE
SEAL

NOTE: MAKE SURE
OF CORRECT
ENGAGEMENT

WASHER

4088

NUT

Diagram 6.5

4140

6.8 Sealed Water Systems ONLY

Adjust the system to initial design pressure. The set pointer on
the pressure gauge should be set to coincide with the indicating
pointer.

6.9 Thermostatic Radiator Valves

If thermostatic radiator valves are fitted care must be taken to
ensure that an adequate flow rate through the boiler when they
close, refer to the current issue of BS7478 for guidance.

6.10 Protection Against Freezing

If the boiler is to be out of use for a period of time during severe
weather conditions we recommend that the whole of the system,
including the boiler, be drained off to avoid the risk of freezing
up.

6.11 Operational Checks and Completion

Adjust the boiler thermostat and any system controls to their
required settings.

Do not attempt to adjust the thermostat calibration screw.
Operate the boiler again on full service and check that the

balancing is satisfactory, making adjustments as necessary.

CONTROLS

COVER

SLIDERS

Diagram 6.6

Fit the front cover by hooking it under at the top and securing
with the wing nut, washer and nut previously removed, refer to
diagram 6.5.

Fit the controls cover by hooking into the sliders and pushing it
back as far as it will go, see diagram 6.6.

23

221972A

7 Instructions to the User

Instruct and demonstrate the safe and efficient operation of the
boiler, heating system and domestic hot water system.

Advise the user, that to ensure the continued efficient 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.

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.

8 Servicing

Notes. To ensure the continued efficient 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,
but in general once a year should be enough.

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

Before servicing turn off the gas and isolate the electrical supply
to the boiler.

After completing a service always test for gas soundness and
carryout functional check on controls.

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

It is the Law that servicing is carried out by a competent person.
Advise the user of the precautions necessary to prevent damage

to the system and building in the event of the heating system
being out of use during frost and freezing conditions.

Reminder - Leave these instructions and the “Benchmark”
logbook with the user.

SECURING
SCREW (4)

4083

FLUEHOOD

8.1 Access

Refer to diagram 6.6 and slide the controls cover forwards and
off.

Remove the outer case, see diagram 6.5.
Note. As an aid to servicing the air pressure switch tube

connection can be used to obtain a products of combustion
reading.

Remove the RED tube from the connection on the air pressure
switch and insert the analyser probe into t he tube.

Switch on the electrical supply to operate the fan and turn the
gas supply on.

On completion of the test switch off the electrical supply and the
gas supply and reconnect the red tube to the air pressure
switch.

8.2 Cleaning Heat Exchanger Flueways

Disconnect the air pressure tubes, see diagram 5.4.
Remove the violet and red electrical connections from the fan,

see diagram 5.4.
Remove the fan complete with fan duct extension taking care

not to damage the gasket, see diagram 5.4.
Vertical Flue Only, carefully remove the restrictor plate and

additional gaskets.
Remove the flue hood, noting that there are keyhole slots at the

rear, see diagram 8.1.
Remove the combustion chamber cover, see diagram 6.3.
Remove the burner as Section 8.3.
Place a sheet of paper in the base of the combustion chamber.
Remove the baffles, note, when replacing they are marked

“Front”, see diagram 8.2.

GASKET

Diagram 8.1

BAFFLE (8 off)

9911

Diagram 8.2

Clean the heat exchanger flueways with a suitable stiff brush.
Remove the paper together with any debris.

8.3 Main Burner

Disconnect the pilot pipe union connector and pilot burner,
securing nut and shakeproof washer together with the pilot
shield. Remove the pilot burner assembly taking care not to
damage the electrode and lead assembly, see diagram 8.3.

221972A

24

8 Servicing

Remove the securing screw from the burner support bracket,
see diagram 8.4.

Remove the main burner from the main injector at the rear.
Raise the burner up and forwards, easing the pilot pipe down,
to clear, take care not to damage the combustion chamber
insulation or the pilot p[pipe.

Use a vacuum cleaner or suitable stiff brush to clean the burner
thoroughly, making sure that all the burner ports are clear and
unobstructed.

Continue cleaning heat exchanger as Section 8.2.
Note. On refitting and after cleaning the heat exchanger make

sure the burner is fitted correctly, that is, located on the main
injector and horizontal.

8.4 Main Injector

With the main burner removed the main injector can be inspected
and cleaned as necessary, see diagram 8.5.

If removing for cleaning do not use a wire or sharp instrument
on the hole.

Use a little suitable sealant on the external thread when refitting
making sure a gas tight seal is made.

SECURING
SCREW

4112

BURNER SUPPORT
SCREW

Diagram 8.4

8.5 Pilot Burner/Electrode and Pilot Injector

Clean the pilot burner and electrode.
To remove the electrode release the spring clip, see diagram

8.6.
When removing and replacing the pilot injector from the pilot

burner take care not to damage the electrode, see diagram 8.6,
clean the injector by blowing through it.

Check that the spark gap is as shown in diagram 6.4.

8.6 Operational Checks

After completing a service and before fitting the case, check
condition of the case seal and renew if necessary.

Examine flue hood and terminal to make sure they are clean
and clear of obstructions.

Light the boiler and carryout the functional checks as described
in Section 6.

SECURING NUT AND
SHAKEPROOF
WASHER

4109

MAIN
BURNER
INJECTOR

PILOT
BURNER

Diagram 8.5

SPRING
CLIP

4111

4143

ELECTRODE AND
LEAD ASSEMBLY

UNION
CONNECTOR

PILOT PIPE

Diagram 8.3

25

ELECTRODE

PILOT
INJECTOR

Diagram 8.6

221972A

9 Fault Finding

9.1 Electrical

Important. On completion of the Service/Fault Finding task
which has required the breaking and remaking of the electrical
connections the earth continuity, polarity, short circuit and
resistance to earth checks must be repeated using a suitable
multimeter.

Refer to neon indicators “An Aid to Fault Finding” diagram 9.1,
Boiler Fault Finding diagram 9.2, Pump Overrun Fault Finding
diagram 9.3, the Functional Flow diagram 9.4 , and the Pictorial
Wiring diagram 9.5.

Neon Indicators - An Aid to Fault Finding

THE NEON INDICATORS ARE AN AID TO FAULT FINDING ONLY. FAILURE OF ANY OF THE NEON INDICATORS DOES NOT WARRANT THE

REPLACEMENT OF AN OTHERWISE SATISFACTORY PRINTED CIRCUIT BOARD (PCB).

9.2 Electrical Supply Failure

Failure of the electrical supply will cause the burner to go out.
Operation will normally resume on restoration of the electrical

supply. If the burner does not relight after an electrical supply
failure the overheat device may need resetting.

Remove the control cover, see diagram 6.6 and push the rest
button on the front of the control box, see diagram 6.1.

If the cutoff operates at any other time press the rest button and
the burner should relight. If the fault persists refer to fault finding
chart.

Note: The pump may run for several minutes when power is first
applied, regardless of call for heat.

4120

Is neon 1 lit?

YES

Is neon 2 lit?

YES

Is neon 3 lit?

YES

Is neon 4 lit?

YES

Is main burner operating?

YES

System satisfactory

NO

NO

NO

NO

NO

Fault with mains supply or PCB fuse

Overheat cut off device tripped or
thermostat, overheat cut off device faulty

- see detailed fault finding chart.

Air flow proving fault - that is fan or air
pressure switch - see detailed fault finding
chart.

Ignition, pilot or flame proving fault ­see detailed fault finding chart.

Multi-functional control/harness problem

- see detailed fault finding chart.

3324

221972A

NEON
INDICATORS

Diagram 9.1

26

9 Fault Finding

Before detailed checking of electrical components ensure that remote controls are calling for heat. Check the gas supply is free of obstructions and purged of
air. Check the overheat cutoff has not operated. For fully pumped systems only. Isolate the electrical supply and physically check ALL cables, connections
and the printed circuit board fuse. Check the air tubes to the air pressure switch. Switch on the electrical supply and check for correct polarity. Turn the
boiler thermostat to its maximum setting. Also check fuses.

Is neon 1 lit?

YES

Is neon 2 lit?

YES

Is neon 3 lit?

YES

NO

NO

YES

Is there 230V~ between SL and
N and between L and N ?

Is there 230V~ between yellow connection
on overheat device and N ?

Is there 230V~
between 3 on thermostat and N ?

NO

Is there 230V~ between
"N/C" on air pressure switch and N ?

Is there 230V~ between "C" on air
pressure switch and N ?

Does fan run?

YES

YES

YES

YES

YES

Replace fan.

NO

NO

NO

NO

NO

NO

Correct power supply problem.

Check overheat reset.
If satisfactory replace overheat device.

Replace thermostat.

Check yellow cable between printed circuit
board and air pressure switch.
If satisfactory replace printed circuit board.

Replace air pressure switch.

Is there 230V~ between motor connections on fan?

YES

Isolate electrical supply test fan
harness continuity.
If satisfactory replace printed circuit board.

NO

Is Neon 4 lit?

YES

Does main burner light?

YES

System satisfactory

NO

YES

YES

Does fan Hunt?

NO

Is there 230V~between "N/O" on air
pressure switch and N ?

Is there a spark at pilot burner?

YES

Does pilot light?

YES

With pilot lit does spark stop?

NO

Isolate supply. Remove plug from the
multifunctional control. Check continuity
of main solenoid between EV2 and COM.
Continuity OK?

YES

Replace multi-functional control.

YES

NO

NO

NO

NO

Replace printed circuit board.

Inspect air tubes for leaks, kinks and correct
fitting. If satisfactory replace faulty air pressure
switch.

Check lead continuity and inspect electrode and
lead for damage.

Check for pilot jet blockage, incorrect electrode
adjustment isolate supply. Remove plug from
multifunctional control. Check continuity of pilot
solenoid between EV1 and COM, continuity OK?

YES

Replace
multifunctional
control

NO

Replace main solenoid

NO

Replace pilot
solenoid.

Inspect electrode lead /connection
for poor contact. Check electrical supply
polarity and correct if necessary.
If satisfactory replace printed circuit board.

M A I N T E R M I N A L S T R I P
C O N T R O L T H E R M O S T A T

27

Diagram 9.2

221972A

9 Fault Finding

Pump Overrun Operation For Fully Pumped System Only

Before using the fault finding chart ensure all wiring is correct and in good condition, the pump is not faulty and check the PCB fuse F2

The pump should run for several minutes after remote controls have stopped calling for heat.

Does the pump run when SL is applied ?

The PCB has a timed pump overrun facility.

NO

YES

Faulty PCB. Replace

Does pump continue to run after
SL is interrupted?

NO

YES

Does pump stop after several
minutes?

NO

YES

System satisfactory.

FOR FULLY PUMPED OPEN VENTED
OR SEALED WATER SYSTEMS ONLY Diagram 9.3

221972A

28

N

N

N

L

N

N

SPARK
ELECTRODE

F1

9 Fault Finding

KEY

bk BLACK
br BROWN
b BLUE
p PURLPLE

L

br

7

F2

PUMP

p

or ORANGE
w WHITE
r RED
y YELLOW

brbr

b

w

9

SL

br

LINK

*

b

or

5750

or

RED

or

PN

b

N

FUSE
F1 & F2
(F1A)

O/H CUTOFF

y

y

rb

FAN

bk

AIR
PRESSURE
SWITCH

y

br b

PILOT
SOLENOID

bk

2

CONTROL STAT

r

(N/O) (C)

(N/C)

MAIN
SOLENOID

y

3

N

N

b

N

b

b

b

Remove red link between 9 and SL when

fitting a time control etc (if no switch is fitted,

*

link will make the circulation pump run constantly)

AIR PRESSURE SWITCH CONNECTIONS
MAIN TERMINAL STRIP CONNECTIONS
CONTROL THERMOSTAT CONNECTIONS
PRINTED CIRCUIT BOARD CONNECTIONS

FULLY PUMPED OPEN VENTED
OR SEALED WATER SYSTEM

29

Diagram 9.4

221972A

9 Fault Finding

KEY:

b-BLUE
bk - BLACK
br - BROWN
g/y - GREEN/YELLOW
or - ORANGE
r-RED
y-YELLOW
w-WHITE
p-PURPLE

NC
NO

5751

g/y

FULLY PUMPED OPEN
VENTED OR SEALED
WATER SYSTEM

FAN

MULTI-FUNCTIONAL
CONTROL

r

b

r

bk

y

AIR
PRESSURE
SWITCH

ELECTRODE

PLUG

C

3-PLUGS

3

CHASSIS EARTH

g/y

g/y

g/y

SEQUENCE

FUSES
F1 & F2

BOARD

p

(F1A)

br

b

or

br

y

p

b

✽ Remove red link between 9 and SL when fitting

a time control etc (If no switch is fitted, link
will make the circulation pump run constantly)

7
8
9

SL

L

N

CHASSIS
EARTH

g/y

br

b

✽ SEE NOTE

br

b

g/y

E

CIRCULATION

L

PUMP

N

L

230V~50Hz

N

PERMANENT
MAINS

E

SUPPLY
FUSED

w

y

2

SWITCH CONTROL,
TIME SWITCH,

AT 3-AMP

PROGRAMMER ETC.
(if fitted)

221972A

CONTROL

THERMOSTAT

OVERHEAT
CUTOFF

Diagram 9.5

30

10 Replacement of Parts

10 Replacement of Parts

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

Before replacing any parts isolate the boiler from the electrical
supply and turn the gas supply off at the gas service cock,
indicator slot should be vertical.

Unless state otherwise, all parts are replaced in the reverse
order to removal.

After replacing any parts always test for gas soundness and if
necessary carryout functional check of controls.

10.1 Access

Gain access as Section 8.1.

10.2 Control Thermostat diagram 10.1
and 10.2

Remove and support the electrical control box, refer to Section

5.6.
Remove the control knob. Remove the electrical connections

from the thermostat body.
Release the thermostat body by unscrewing the two screws and

shakeproof washers in the front of the control box.
Remove the split pin and withdraw the thermostat phial from its

pocket. Release the capillary from the base and plastic retaining
clip then remove it from the split grommet. Release the capillary
from its clips. Remove the thermostat complete from the boiler.

Reassembly note. When fitting the thermostat, make sure that
the thermostat phial is covered with heat sink compound then
fully inserted into the phial pocket and that the capillary is within
the gland seal, see diagram 10.2. Remake the electrical
connections. There must be no kinks or sharp bends in the
capillary.

10.3 Over Heat Cutoff Device - diagram 10.1,

10.2 and 10.2A

Remove and support the electrical control box, refer to Section

5.6.
Remove the overheat cutoff electrical connections.
Disconnect the air pressure switch plug from the PCB.
Remove the locking nut from the overheat cutoff.
Release the capillary from the retaining clips then remove it

from the split grommet.
Remove the split pin and then the phial.
When refitting use the heat sink compound supplied.

SHAKEPROOF
WASHERS AND
SCREWS

CONTROL
KNOB

LOCKNUT

ELECTRICAL
CONNECTIONS

CONTROL
THERMOSTAT

5755

ELECTRICAL
CONNECTIONS
YELLOW 2 & 3

SPLIT
GROMMET

RETAINING
CLIP

Diagram 10.1

31

221972A

10 Replacement of Parts

PHIAL
POCKET

SPLIT
PIN

OVERHEAT
CUTOFF
DEVICE
PHIAL

SPLIT
PIN

RETAINING
CLIP

GLAND SEAL
(Right hand illustrated)

NOTE: All capillaries and
cables should be
situated within the
"Gland Seal".

THERMOSTAT
PUMP
OVERRUN
PHIAL

PHIAL
POCKET

Diagram 10.2

4110

ELECTRICAL PLUGS

CHASSIS
EARTH
CONNECTION

MAIN
TERMINAL
STRIP
SECURING
SCREW (2)

ELECTRICAL
CONNECTION

SL BROWN CABLE

PLASTIC
RETAINING
CLIP

OVERHEAT
CUTOFF
ELECTRICAL
CONNECTION
"WHITE"
CABLE

IGNITION
LEAD

ELECTRICAL
CONNECTION

N BLUE CABLE

Diagram 10.2A

5756

BOILER
THERMOSTAT
ELECTRICAL
CONNECTION
NO.3"YELLOW"
CABLE

SUPPORT
POST (4)

3328

10.4 Control Board (PCB) - diagram 102A

Release the control box, refer to Section 5.6.
Disconnect the three electrical plugs and ignition lead.
Release the cables from the plastic retaining clip, then disconnect

the cables from the PCB to the main terminal strip, control
thermostat and earth connection.

Release the main terminal strip and plastic label.
Carefully pull the board away from its supports.
When refitting refer to wiring diagram 9.5.

10.5 Pilot Burner and Pilot Injector

Proceed as Section 8.3 and 8.5.

10.6 Electrode

Proceed as Section 8.3 and 8.5.
Gain access as Section 5.6 to remove lead from control box.

221972A

10.7 Multifunctional Control - diagram 10.3

Disconnect the pilot supply by unscrewing the tubing nut at the
multifunctional control, take care as there is a restrictor on the
pilot pipe.

Disconnect the electrical plug.
Support the multifunctional control, remove the four extended

screws from the flanged connections at the left and right hand
side.

Remove and discard the original “O” rings from the flanged
connections and fit the new “O” ring supplied, into recess,
before fitting the replacement multifunctional control.

After assembly test for gas soundness and purge in accordance
with the current issue of BS6891.

32

10 Replacement of Parts

10.8 Solenoid - diagram 10.3

Remove the electrical plug from the multifunctional control.
Remove the securing screw and then the solenoid Assembly.

10.9 Main Burner

Remove the main burner as Section 8.3.

4123

RESTRICTOR

10.10 Main Injector

Remove the main burner as Section 8.3.
Remove the main injector as Section 8.4.

10.11 Insulation - 10.4
Combustion Chamber Front

Remove the retaining screw then the insulation.

Sides

Slide the insulation out.

Rear

With the side insulation removed the rear insulation can be
removed and replaced.

10.12 Viewing Window - diagram 10.5

Remove the old self adhesive aluminium foil gasket and the old
mica window. Replace with a new mica window. Peel off the
backing paper and secure with new self adhesive aluminium foil
gasket, see diagram 10.5. Ensure no air bubbles are trapped
underneath the foil.

Important

Make sure that the mica window fully covers the opening and
that the hole in the aluminium foil gasket is centred over
opening.

PILOT PIPE
TUBING NUT

SOLENOIDS

ELECTRICAL
PLUG

SECURING
SCREW

EXTENDED
SCREW (8)

Diagram 10.3

10.13 Air Pressure Switch - diagram 10.6

Release the control box as Section 5.6.
Remove the air pressure tubes and electrical connections from

the PCB, release the screws and remove the switch.
When fitting the replacement make sure that the plastic tubes

and electrical connections are made as shown in diagram 9.5
and 10.6.

10.14 Fan - diagram 5.4

Remove the electrical connections and disconnect the air
pressure tubes.

Remove the fan assembly securing screws at the front and
slacken those at the rear and withdraw the assembly.

Make sure that the earth connection is remade onto the new fan
assembly.

The polarity of the other connections is not important.

33

221972A

RETAINING
SCREW

FRONT INSULATION

10 Replacement of Parts

OPENING

4118

SELF ADHESIVE
ALUMINIUM FOIL
GASKET

(INSIDE FACE OF THE
BOILER FRONT COVER)

MICA WINDOW

7907

PEEL
OFF
BACKING
PAPER

Diagram 10.5

SIDE INSULATION

REAR INSULATION

Diagram 10.4

AIR PRESSURE
SWITCH TUBES

SECURING
SCREWS

ELECTRICAL
CONNECTIONS

CLEAR

4122

RED

AIR

PRESSURE

SWITCH

CONTROL
BOX

221972A

Diagram 10.6

34

10 Replacement of Parts

11.1 Part Identification

The key number on the diagram and the list will help to identify
the part.

11.2 Ordering

When ordering any spare parts please quote the number and
description from the list together with the model name and serial
number.

If ordering from Britsh Gas also quote the GC number of the
appliance and part.

Key No. Part No. Description GC Part No.

1 800442 Multifunctional control 278 021
2 208040 “O” ring 334 592
3 205710 Injector 80ff 278 024
4 203432 Pilot burner 278 023
5 801236 Mica window & Gasket *******
6 800421 Fan assembly 278 008
7 202626 Spark electrode and lead 313 998
8 K3580 Clip 390 983
9 800850 Thermostat
10 202201 Air pressure switch 313 992
11 800400 Control knob 313 917
13 202015 Fuse 334 750
14 900847 Control board PCB
15 800479 Overheat cutoff device 278 188

35

221972A

11 Spare Parts

5761

2

6

1

5

10

4

7

8

11

3

9

15

14

13

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

221972A

36

Diagram 11.1