Glow-worm Energysaver Combi 80, Energysaver Combi 100 Instructions For Use Manual

Hepworth Heating Ltd.,

Nottingham Road, Belper, Derbyshire. DE56 1JT

General/Sales enquiries:

Tel: [phone] Fax: [phone]

One Contact Local Service

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

221564F.11.00

All replacement parts
All labour charges
All call-out charges

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 First Year Guarantee.

In the centre 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:

Guarantee Registration

This is a Cat I2H Appliance

Reference in these instructions to British Standards and Statutory

Regulations/Requirements apply only to the United Kingdom.

For Ireland the rules in force must be used.

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

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.

To be left with the user

6548

❏

✔

❏

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❏

✔

Instructions for Use

Installation and Servicing

G.C. No. 47-047-01 G.C. No. 47-047-02

REGISTER YOUR GLOW-WORM APPLIANCE

FOR 1ST YEAR GUARANTEE PROTECTION

CALL 0208 247 9857

Energysaver

Combi

80 100

Condensing

Combination Boiler

Energysaver
Combi

2

221564F

General

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

Once the controls are set, the boiler is automatic in operation.
The Energysaver 80 and 100 Combi boilers are able to provide

room heating as part of a central heating system and domestic
hot water direct from the cold water supply, without the need for
secondary storage.

Gas Category

This boiler is for use only on G20 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 the above regulations.

Gas Testing and Certification

The boiler is tested and certificated for safety and performance.
It is, therefore, important that no alteration is made to the boiler
unless approved, in writing, by 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.

CE Mark

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

Type test for purposes of Regulation 5 certified by:

Notified body 0063.

Product/production certified:

Notified body 0063.

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 electrical equipment designed for
use within certain voltage limits.

3. Directive 89/336/EEC on the approximation of the Laws of
the Members States relating to electromagnetic compatibility.

Control of Substances Hazardous to Health

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

The adhesives and sealants used in this appliance are cured
and give no known hazard in this state.

Refractory Ceramic Fibre

This product uses insulation material containing Refractory
Ceramic Fibre (RCF), which are man-made vitreous silicate
fibres. Excessive exposure to these materials may cause
temporary irritation to eyes, skin and respiratory tract,
consequently, it makes sense to take care when handling these
articles to ensure that the release of dust is kept to a minimum.

To ensure that the release of fibres from these RCF articles is
kept to a minimum, during installation and servicing we
recommend that you use a HEPA filtered vacuum to remove
any dust accumulated in and around the boiler before and after
working on the boiler. When replacing these articles we
recommend that the replaced items are not broken up, but are
sealed within heavy duty polythene bags, clearly labelled as
RCF waste. This is not classified as “hazardous waste” and
may be disposed of at a tipping site licensed for the disposal of
industrial waste.

Contents

Important Information

Introduction 3
Operating the Boiler 3
Clock Setting 5

General Information 1 6
Boiler Position 2 8
Flue Location and Ventilation 3 9
Heating System 4 11
Domestic Hot Water System 5 13
Installation Preparation 6 13
Flue Preparation 7 15
Boiler Fixing 8 17
Gas, Water and Condensate Conns. 9 17
Electrical Connections 10 18
Commissioning 11 20

Servicing 12 25
Fault Finding 13 29
Replacement Parts 14 32

CONTENTS DESCRIPTION SECTION PAGE No.

INSTRUCTIONS

FOR USE

INSTALLATION

INSTRUCTIONS

SERVICING

INSTRUCTIONS

3 221564F

Important Information

Protective clothing is not required when handling these articles,
but we recommend you follow the normal hygiene rules of not
smoking, eating or drinking in the work area and always wash
your hands before eating or drinking.

Insulation Pads/Ceramic Fibre, Glass yarn

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.

Introduction

Gas Leak or Fault

If a gas leak or fault exists or is suspected, turn the boiler mains
electrical supply off and turn off the gas supply at the meter.
Consult your local gas company or your local installation/
servicing company.

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. If not, the boiler safety cut-off may have
operated, please refer to the following section to reset.

Reset any external controls, to resume normal operation of the
central heating.

The digital timer, if fitted, has a lithium battery back up and will
not need resetting.

Reset Button

Refer to diagram 1 which shows the fascia behind the drop
down panel.

If the burner goes out check the digital display. Flashing digits
on the display indicate a fault. Allow the boiler to cool down for
at least four minutes then press the ‘Reset’ button. This should
restart the boiler.

To obtain service call your installer or Heatcall (Glow-worm’s
own service organisation) using the telephone number given on
the front page of these instructions.

6561

Diagram 1

PRESSURE
GAUGE

FASCIA

RESET
BUTTON

DIGITAL
DISPLAY

MODE

BUTTON

Operating the Boiler

To Operate the Boiler

1. Check that all five isolating valves are open with their slots
in line with the length of the valve, see diagram 8.1 in Installation
instructions.

2. CAUTION: A sealed pressurised system must be filled and
pressurised by a competent person.

Only operate the boiler when you are sure that the system has
been filled and pressurised. Check this by looking at the

pressure gauge which should read a minimum of 1.0bar, see
diagram 1.

3. Open a hot water tap, check that water flows, then close it.

4. If you are in any doubt about the boiler being filled with water
contact your installation/servicing company or the local gas
company.

5. Check that the electrical supply to the boiler is ON at the
external isolator.

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 to the eyes or severe irritation to the skin
seek medical attention.

4

221564F

6. Set clock/timer (if fitted) and any remote controls as required.

7. If the display is flashing, press the 'reset' button, shown on
diagram 1.

8. The boiler should now operate. It is factory preset to supply
domestic hot water up to 65oC and central heating up to 70oC.

User Controls

The operation of the boiler can be altered by using the ‘Mode’
button. Temperature Selection and Control Options are detailed
in sections 11.8 to 11.11.

Additional Options

Other modes are available by repeatedly pressing the ‘Mode’
button. These cover fault indication and servicing and should
only be accessed by the service engineer. Repeated pressing
of the ‘Mode’ button will eventually return the display to show
boiler temperature, see diagram 11.4.

To Turn the Boiler Off

It is preferable to leave the electrical supply on whenever
possible to permit operation of the built-in frost protection (see
‘Protection Against Freezing’) and daily pump and valve exercise.

To turn off the central heating use the room thermostat or clock/
timer.

To turn off the domestic hot water select

(see section 11.8

and diagram 11.4).
For holiday mode, refer to section 11.8.
To turn off the boiler for servicing, isolate it from the electrical

supply. To turn it on again follow the instructions given in ‘To
Operate the Boiler’.

Maintenance and Servicing

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 Heatcall (Glow­worm’s own service organisation) using the telephone number
on the back cover of this booklet.

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.

Clearances

If the boiler is fitted into a compartment or cupboard do not use
the compartment or cupboard for storage.

Protection Against Freezing

The boiler has a built in frost protection programme as long as
the electricity and gas are left switched on.

This device only protects the boiler. Any other exposed areas
of the system should be protected.

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 combination boiler, should be
drained to avoid the risk of freezing.

If in doubt, contact you installation/servicing company for advice.
As a safety feature the boiler will stop working if the condensate

drain becomes blocked. The display will repeatedly flash ‘

0’

then

‘8*’. 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.
Press the reset button to restart the boiler. Contact your
installation / servicing company if the fault persists.

Draining and Filling

CAUTION: This boiler works in a pressurised system which
must only be drained, refilled and pressurised by a competent
person.

NOTE: If the pressure gauge indicates a loss of system
pressure, i.e. less than 0.7bar, the appliance will shut down
showing flashing:

‘1’ then ‘2*’ on the display. YOU MUST

CONTACT YOUR INSTALLER.

Pressure Relief Safety Valve

CAUTION: A pressure relief safety valve and discharge pipe is
fitted to the boiler. This valve must not be touched. Should there
be any discharge from the pipe, isolate the boiler electrical
supply and contact your installation/servicing company.

Cleaning

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

The boiler casing can be cleaned using a mild liquid detergent
with a damp cloth, then a dry cloth to polish.

Do not use any form of abrasive or solvent cleaner as you may
damage the paint work.

Boiler Casing

CAUTION. Do not remove or adjust the casing in any way, as
incorrect fitting may result in incorrect operation or failure to
operate at all. If in doubt seek advice from the local gas
company or your installation/servicing company.

Replacement Parts

If replacement parts are required apply to your local supplier or
British Gas.

Please quote the name of the appliance.

Condensation Pluming

Like all condensing boilers this appliance will produce a plume
of condensation from the flue terminal in cool weather. This is
due to the high effiency and hence low flue gas temperature of
the boiler.

Operating the Boiler

5 221564F

Setting Instructions for Electro/mechanical
Clock - if fitted

Refer to diagram 2.
This clock has a twenty four hour dial, i.e. 1pm is '13'.
To set the time, turn the whole face clockwise until the pointer

is against the time of day.
To set any “Off” time, push the tappets outwards.
To set any “On” time, push the tappets inwards.
Time can be set either “On” or “Off” in fifteen minute segments.
Note. The clock supplied is fitted with an override device, which

switches the clock programme “On” or “Off” permanently.The
switch will need to be repositioned to resume programmed
working.

0

I

12

13

14

15

16

17

18

19

20

21

22

23

24

1

2

3

4

5

6

7

8

9

10

11

0

I

CONSTANT OFF
PROGRAMMED
CONSTANT ON

Diagram 2

OVERRIDE
SWITCH

POINTER

CLOCK FACE

TAPPETS

4956

Setting Instructions for the 7 Day Digital
Clock/Timer - if fitted

Diagram 3

5673

MON/FRI

ON - 06:30
OFF - 08:30
ON - 16:30
OFF - 22:30

SAT/SUN

ON - 07:00
OFF - 09:00
ON - 16:00
OFF - 23:00

AUTO

RUN

MT

WTh

FS

Su

P

DAY HR MIN

P

R

I

Refer to diagram 3.

Clock Setting

This is a 24 hour clock/timer, that is 1pm is '13:00', and has 8
“ON” and 8 “OFF” daily switching actions.

It is fitted with a lithium battery back up which protects the
programme in the event of an electrical failure. The battery
should have a life of several years.

Setting the Clock

1. With both AUTO and RUN switches set to the central
position, press R reset button, the display will flash.

2. Set RUN switch to .

3. Set day of week by pressing button DAY.

4. Set time of day by pressing buttons HR and MIN.

5. Set RUN switch to the central position, colon will flash, this
indicates the clock is set.

With the clock set, the factory preset programme shown below
will operate.

Setting Timed Programmes

With the clock set to the correct time, see SETTING THE
CLOCK paragraphs 1-4, and then continue as follows:

1. Set RUN switch to P , the display will
indicate the 1st (ON) preset programme and the
symbol

.

2. Set day of week to be programmed by pressing the
DAY button.

Note. The days can be selected individually or
as groups:

Mon-Fri., Mon-Sat., Mon-Sun., Sat/Sun.
An arrow will be displayed under the day or

days selected.

3. Set time of day by pressing the buttons
HR and MIN.

4. Press button P to confirm programmes, the
display will indicate the 2nd (OFF) preset

programme and subsequently, 3rd, 4th, 5th, 6th.
7th, 8th to 16th.

5. Repeat procedures 2, 3 and 4 until desired
programmes are set.

Note. It is not a requirement to use all of the 8 on
and 8 off programmes.

6. Set the RUN switch the central position, your
appliance will now operate at the programmed times.

General Notes.
With the AUTO switch in the I position the central heating will

operated constantly ON.
With the AUTO switch in the O position the central heating will

not operate.
Soft Override button indicated by the symbol

, this
function will override the current central heating programme for
the next available.

ON time programmes are indicated by the symbol

.

6

221564F

1.1 Installation

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

WARNING: When installing the appliance, care should be taken
to avoid any possibility of personal injury when handling sheet
metal parts.

The installation of this boiler must be carried out by a competent
person in accordance the rules in force in the countries of
destination.

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

1.2 Gas Supply

This boiler is for use only on G20 gas.
The gas installation must 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.

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.

1.3 Data Label

The data label is on the base panel inside the appliance.

1.4 Electrical Supply

WARNING: The boiler must be earthed.
All system components shall be of an approved type and all

wiring to current I.E.E. wiring regulations.
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.

1 General Information

Diagram 1.1

Isolation should be by a double pole switched fused spur box,
with a minimum gap of 3mm for both poles. The fused spur box
should be readily accessible and preferably adjacent to the
appliance. It should be identified as to its use.

Alternatively connection can be made through an unswitched
shuttered socket and 3A fused 3 pin plug.

The mains supply cable and other cables connected to the
boiler must be the PVC flexible type of at least 0.75mm

2

(24/

0.20mm).
The colours of three core flexible cable are, blue - neutral,

brown - live, green and yellow - earth.
The wire coloured blue must be connected to the terminal

marked “N” or “Black”.
The wire coloured brown must be connected to the terminal

marked “L” or “Red”.
The wire coloured green and yellow must be connected to the

terminal marked “E” or “Green” or the earth symbol

.

1.5 Condensate

Being a condensing boiler, a condense drain MUST be fitted.
Condensate should, if possible, be discharged into the internal

household draining system, i.e. sink or washing machine drain.
If this is not practical, discharge can be made externally into the

household drainage system or a purpose designed soak away.
It is recommended that any external condensate drain pipe is

insulated and preferably of larger diameter to prevent it freezing
up in adverse weather conditions.

The condensate drain pipe should be checked during servicing
and any debris removed.

Refer to the British Gas Publication “Guidance Note For The
Installation of Domestic Condensing Boilers” for further
information.

C

L

BOILER

CONDENSATE
DRAIN

INSIDE WALL
FIXING FACE

SPIGOT

Condensate Drain
Connection

101

145

373

208

520

118

33

145

REFER TO THE WALL TEMPLATE
FOR PIPE DIMENSIONS

145

6513

(ES80)890

(ES100)985

7 221564F

1 General Information

Diagram 1.2

■ For larger systems use an additional expansion vessel.

● Ball valves are fitted in water and gas connections, plus a drain point on all water connections.

80 100

Lift Weight 72kg (158.7lb) 77kg (169.7lb)
Total Weight (packed) 76kg (167.5lb) 81kg (178.6lb)
Total Weight (installed) 94kg (207.2lb) 99kg (218.3lb)

● Gas connection Rc1/2 (1/2in BSPT)

● Heating and return 22mm compression

● Domestic hot water 15mm compression

Safety valve Preset 3bar (43.5lbf/in

2

)

Safety valve discharge 15mm copper

80 100

Water content (heat exch) 2.7 ltr (0.59 gall) 4 ltr (0.88 gall)
Water content (primary store) 13 ltr (2.86 gall) 12.4 ltr (2.7 gall)
Water content (domestic) 1.3 ltr (0.29 gall) 2 ltr (0.44 gall)

■ Expansion vessel capacity 7 litres (1.54 gallons)
Charge pressure 0.5bar (7.3lbf/in

2

)

Heating system 0.7bar (10.1lbf/in

2

)

minimum pressure

Domestic hot water flow rate

80 100
temp rise 300C 11.4l/min (2.5gall/min) 13.3l/min (2.9gall/min)
350C 9.8l/min (2.2gall/min) 11.4l/min (2.5gall/min)

Maximum flow temperature 650C
Minimum working pressure 0.1bar

■ Maximum heating 130 litres

system water (28.6 gallons)
content using at 75

0

C

fitted expansion average system
vessel, pressurised temperature
at 1bar.

Electrical supply 230V~50Hz

Electrical rating 115W fused 3A

TABLE 2

6499

NOMINAL kW 80 27.5 27.5 8.0
HEAT Btu/h 93,830 93,830 27,266
INPUT kW

100

32.5 32.5 10.2

GROSS Btu/h 110,890 110,890 34,802

NOMINAL kW 80 24.5 24.5 6.8
HEAT Btu/h 83,600 83,600 23,200
OUTPUT kW

100

28.8 28.8 8.9

Btu/h 98,266 98,266 30,367

COND. kW 80 25.5 25.5 7.7
HEAT Btu/h 87,000 87,000 26,170
OUTPUT kW

100

30.5 30.5 9.8

Btu/h 104,066 104,066 33,438

BURNER

mbar

80

-4.5 -4.5 -0.5

MANIFOLD

wg

-1.8 -1.8 -0.2

SUCTION
PRESSURE

mbar

100

-4.8 -4.8 -0.5

HOT(APPROX)

wg -1.92 -1.92 -0.2

80

9.2-9.6 9.2-9.6 9.2-9.6

BURNER

9.0-9.4 9.0-9.4 9.0-9.4

%CO

2

100

9.2-9.6 9.2-9.6 9.2-9.6

9.0-9.4 9.0-9.4 9.0-9.4
m3/h 80 2.6 2.6 0.7
ft3/h 91.8 91.8 24.7

D.H.W Max. 8bar
working pressure (150lbf/in2)

IP classification IP40
Internal Fuse rating 1) Type 2AF

2) Type 2AF

3) Type 3AT

TABLE 1 C.H. Max D.H.W.Max MIN

CASING
DOOR ON

CASING
DOOR OFF

CASING
DOOR ON

CASING
DOOR OFF

m3/h

100

2.9 2.9 0.9

ft3/h 102.4 102.4 31.8

APPROX.
GAS RATE

SCHEMATIC LAYOUT OF BOILER

8

221564F

2.1 Location

The boiler is not suitable for fitting outdoors.
Any electrical switch or boiler control using mains electricity

must be positioned so that it cannot be touched by a person
using a bath or shower.

The boiler must be mounted on a flat wall which is sufficiently
robust to take its weight, refer to Table 2.

2.2 Clearances

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

2.1.
Additional clearances may be beneficial around the boiler for

installation.
For flue installations where external access is not practicable,

consideration should be given for the space required to insert
the flue internally which may necessitate clearance larger than
those specified in diagram 2.1.

*

*

*

*

Increase to 25mm clearance from
combustible material.

Diagram 2.1

6498

5

5

200

† 600

5

5

25

200

MINIMUM CLEARANCE FROM
PERMANENT SURFACES

† A removable compartment door can be
placed at least 5mm in front of the appliance.

2 Boiler Position

Dimensions in millimetres

9 221564F

3 Flue Location and Ventilation

3.1 Flue Position and Length

There are several flueing options available for the Energysaver
Combi, e.g. horizontal, vertical and twin flue.

The standard horizontal flue is fitted onto the top of the boiler
using the flue elbow.

See diagrams 3.1 to 3.3 to determine whether a standard flue
can be used.

The standard flue can be extended using 1m long extension kits
and 90° elbows. A maximum of 3500mm of extension pipes plus
3x90° bends can be added to the standard horizontal flue
length.

NOTE: When extension pipes are used the flue system must be
designed to have a continuous fall to the boiler of at least 2.5°
to facilitate the removal of condensate.

3.2 Internal Flue Installation

The flue can be installed from inside the building, when access
to the outside wall face is not practicable.

Diagram 3.2

Diagram 3.3

SIDE FLUE - STANDARD Left

SIDE FLUE - STANDARD Right

DISTANCE 'Y' = 307 TO 755mm

WALL THICKNESS 'X' = 75 TO 554mm

6502

6501

REAR FLUE - STANDARD

DISTANCE 'Y' = 393 TO 755mm

"X"

"Y"

6503

"Y"

3.3 Terminal Position

The minimum acceptable siting dimensions for the terminal
from obstructions, other terminals and ventilation openings are
shown in diagram 3.4.

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

Being a condensing boiler some pluming may occur from the
flue outlet. This should be taken into consideration when
selecting the position for the terminal.

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 made of plastic sheeting. If the car port
comprises of a roof and two or more walls, seek advice from the
local gas supply company before installing the boiler.

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

Diagram 3.1

10

221564F

3.4 Terminal Guard

A terminal guard is required if persons could come into contact
with the terminal or the terminal could be subject to damage.

If a terminal guard is required, it must be positioned to provide
minimum of 50mm clearance from any part of the terminal and
be central over the terminal.

The guard should be similar to that shown in diagram 3.5.
A suitable guard can be obtained from.
Tower Flue Components
Morley Rd.
Tonbridge
Kent
TN9 1RA.
Their Reference CGD K3 BL.

3.5 Timber Frame Buildings

If the boiler is to be installed in a timber frame building it should
be fitted in accordance with the Institute of Gas Engineers
document IGE/UP/7/1998. If in doubt seek advice from the local
gas undertaking or Hepworth Heating Ltd.

3.6 Room Ventilation

The boiler is room sealed, so when it is installed in a room or
space, a permanent air vent is not required.

3.7 Cupboard or Compartment Ventilation

Due to the high efficiency and hence low casing temperature of
this boiler, cupboard or compartment ventilation is not necessary.

3 Flue Location and Ventilation

A

A

F

G

E

A

G

G

G

B,C

B,C

F

F

K

K

K

C

G

L

L

UNDER CAR PORT etc.

H,I

J

D

F

K

2816

Diagram 3.4

MINIMUM SITING DIMENSIONS FOR
FANNED FLUE TERMINALS
POSITION

MM
A DIRECTLY BELOW AN OPENABLE

WINDOW, 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 INTERNAL CORNERS 300*
G ABOVE ADJACENT GROUND OR

BALCONY LEVEL 300
H FROM 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 EXTERNAL CORNERS 300

M

Diagram 3.5

TERMINAL GUARD

* It may be necessary to increase this dimension to prevent

staining of adjacent walls depending on weather conditions.

11 221564F

4.1 General

The boiler is for use in sealed water systems only.
The safety valve is an integral part of the boiler and it cannot be

adjusted.

A pressure gauge is incorporated into the boiler to indicate the
system pressure.

The circulation pump is integral with the boiler, see diagram 4.1.

4.2 Expansion Vessel

The boiler has an integral expansion vessel with a capacity of
7 litres (1.54 gallons), with a charge pressure of 0.5bar.

The maximum heating system water content using the fitted
expansion vessel is 130 litres at an average temperature of
75

O

C, and charge pressure of 1.0bar.

4.3 Flow Rate

The minimum flow rate through the boiler is 400 litres/hr for
ES80 and 470 litres/hr for ES100. This is equal to 20OC
differential at maximum heat input.

The system can be fitted with a lockable balancing valve if
necessary in the main flow or return pipes shown as valve "A"
in diagram 4.2.

Diagram 4.1

6558

7

METRES WG

UPS 15-60 PUMP

AVAILABLE PUMP HEAD

BOILER PRESSURE LOSS CURVE

= SETTING 1
= SETTING 2
= SETTING 3

0

0 0.25 0.5 0.75 1.0 1.25 1.5 1.75 2.0 2.25 2.5

1

2

3

4

5

6

HEATING SYSTEM FLOW RATE X 1000 l/hr

4.4 Bypass

The boiler is fitted with a manual bypass, see diagram 4.3. This
valve may be adjusted by the installer if necessary to ensure at
least 400 litres/hr for ES80 and 470 litres/hr for ES100 flow
through the boiler. The boiler is supplied with the bypass open
by approximately half a turn and is closed by turning the white
screw clockwise. However for systems completely fitted with
thermostatic radiator valves or systems of high pressure loss an
additional bypass valve must be fitted to the heating circuit to
ensure that under no circumstances does the flow rate drop
below this level.

An additional bypass valve “B” is shown in diagram 4.2.

4.5 Filling Sealed Systems

Provision for filling the system at a low level must be made. Two
methods of filling are shown in diagram 4.4. There must be no
permanent connection to the mains water supply, even through
a non-return valve.

4 Heating System

12

221564F

7265

Diagram 4.2

Diagram 4.3

6597

MANUAL
BYPASS
VALVE

4.6 Water Treatment

For optimum performance after installation, the boiler and its
associated central heating system should be flushed in
accordance with BS7593:1992 using a cleanser such as Sentinel
X300 or X400, or Fernox Superfloc.

For long term corrosion protection, after flushing, an inhibitor
suitable for aluminium heat exchangers should be used.
Examples are Sentinel X100 and Fernox Copal.

4.7 Draining Tap

A draining tap must be provided at the lowest points of the
system, which will allow the entire system to be drained.

The flow and return isolation valves are provided with drain
points for boiler heat exchanger drainage, see diagram 8.1.

4 Heating System

BOILER

DOMESTIC

WATER

HOT

COLD SUPPLY

DRAIN
POINT

'B'

'A'

FLOW CONTROL
VALVE

HEATING
CIRCUIT

RETURN

ADDITIONAL
EXPANSION
VESSEL
(if required)

OPTIONAL
BY-PASS
VALVE

OPTIONAL FILLING
ARRANGEMENTS,
SEE DIAGRAM 4.4

C

METHOD 1

METHOD 2

SUPPLY STOP
VALVE

SUPPLY
PIPE

HOSE
UNIONS

SERVICING
VALVE

TEMPORARY
HOSE

HEATING
SYSTEM

HEATING
SYSTEM

TEMPORARY
HOSE

HOSE
UNIONS

SERVICING
VALVE

SUPPLY
PIPE

SUPPLY STOP
VALVE

DOUBLE CHECK
VALVE ASSEMBLY

COMBINED
CHECK VALVE
AND VACUUM
BREAKER

C

C

Diagram 4.4

7266

13 221564F

5.1 Water Pressure

The maximum working pressure of the domestic hot water
circuit is 8 bar.

If the cold water supply pressure exceeds the maximum, a
pressure reducing valve must be fitted in the supply to the boiler.

5.2 “Hard” Water Areas

The temperatures within the heat exchanger are limited by the
boiler control system to minimise scale formation within the hot
water pipework. However, in areas where the water is “hard”
(i.e. more than 200mg/litre), it is recommended that the hot

water setting is adjusted from

to (see section 11.8 and
diagram 11.4) and that a scale reducer is fitted.
Refer to the manufacturer’s instructions or consult the local

water company for additional advice.

5.3 Domestic Water Flow Rate

The water flow rate is governed to a maximum 12 litre/min by a
restrictor fitted into the boiler pipework.

5.4 Mixing Valve

There is a domestic hot water mixing valve fitted to the boiler
base and this is factory set at approximately 60

O

C. This can be
adjusted if necessary to supply a lower temperature. Turn the
5mm adjuster anticlockwise to reduce the temperature, see
diagram 14.7. The domestic hot water temperature can also be
adjusted, see section 11.8.

6 Installation Preparation

6.1 Wall Mounting Pack

The wall mounting pack contains everything required to pre­plumb the boiler, including the wall mounting jig, hanging
bracket, wall template, screw pack, room thermostat and safety
valve discharge pipe, along with these instructions.

6.2 Wall Template

Remove the wall template from the wall mounting pack and
place in the desired position on a flat wall, giving due consideration
to boiler clearances, see section 2.

6.3 Flue Hole Cutting

The standard horizontal flue is designed with an internal fall
of 35mm/metre towards the boiler for disposal of condensate.
If the standard flue length alone is being used then the flue hole
of diameter 105mm can be cut in the position marked on the wall
template.

For standard side flues the horizontal flue centre line on the
wall template should be extended to the side wall, and the
vertical centre of the flue hole marked at 208mm from the back
wall.

For installations with external access, a 105mm diameter core
drill can be used.

For installations with internal access only a 125mm diameter
core drill should be used.

When using extension pipes with the horizontal rear flue, a core
drill size of 125mm should be used to allow the extension pieces
to slope at 35mm/metre (2.5

0

) towards the boiler.

For extended side flues, the flue hole centre should be
determined by extending the dashed inclined line on the template
to the side wall. This dashed line is drawn at 35mm/metre (2.5

o

)
rise from the boiler. Where this line reaches the side wall, a
horizontal line should be marked. The vertical centre line of the
flue should then be marked at 208mm from the back wall, see
diagram 6.1.

5 Domestic Hot Water System

To allow for the flue passing through the wall at this angle a
125mm hole should be drilled irrespective of internal or external
installation.

If necessary remove the wall template whilst drilling the flue
hole.

6.5 Wall Mounting Jig and Hanging Bracket
Fixing

If previously removed, reposition the wall template over the flue
hole and mark the position of the fixing holes for the jig and the
hanging bracket.

Drill the four fixing holes using a 7mm dia. drill bit and insert wall
plugs supplied.

If gas and/or water pipes are to be plumbed through the rear wall
directly into the wall mounting jig holes, the holes must be drilled
as marked on the wall template prior to fixing of the wall
mounting jig.

Secure the wall mounting jig and hanging bracket using the
screws and washers supplied, see diagram 6.2.

14

221564F

6.5 Pre Plumbing

The wall mounting jig can now be pre-plumbed without the
boiler being mounted if necessary. All water, gas and electric
connections are on the wall mounting jig with the exception of
the condense drain, the position of which is shown on the wall
template for pre plumbing purposes. See sections 9 and 10 for
details of gas, water, condensate and electrical connections.

6.6 Unpacking of Boiler Carton

Cut the straps that secure the carton and the boiler to its transit
pallet and open the top flaps of the carton. Carefully remove the
top packing piece which contains the user control door and
place to one side until required. Remove the carton and edge
packing. To assist in lifting the boiler it is advisable to remove the
casing door by removing the two securing screws.

6.7 Optional Mini Expansion Vessel

As an option a mini expansion vessel can be fitted to the
domestic pipework as shown in diagram 6.3.

For ease of installation the vessel should be fitted to the boiler
prior to it being lifted to the wall.

Remove the right hand casing panel of the boiler as described
in section 12.7.

Remove the 1/2" plug fitted into the domestic pipework.
Fit the mini expansion vessel using a suitable thread sealant to

make a water tight seal.

2.5˚
Inclined

Horizontal

Extended flue length

Standard flue length

Diagram 6.1

Diagram 6.2

6511

6525

WALL
TEMPLATE

WALL PLUG
(2 OFF)

WASHER
(2 OFF)

SCREW
No12 x
50mm
(2 OFF)

WALL PLUG
(2 OFF)

SCREW No12 x 50mm
(2 OFF)

WALL
TEMPLATE

EXTENDED SIDE FLUE

BOILER MOUNTING

HANGING
BRACKET

WALL
MOUNTING JIG

208

Ø 125

6 Installation Preparation

Diagram 6.3

6559

MINI
EXPANSION
VESSEL

1/

2

" PLUG

REMOVED

90

0

15 221564F

7.1 Flue Length

Note: All dimensions are in mm.
For a rear flue, measure the distance from the outside wall face

to the boiler mounting wall. Check that the flue length will be
suitable, see diagram 3.1 for a standard flue system.

For a side flue, measure the distance from the outside wall face
to the flue outlet centre line of the boiler. Check that the flue
length will be suitable, see diagram 3.2 for a left hand flue
system or diagram 3.3 for a right hand flue system.

If the measurement exceeds those shown in diagrams 3.1 - 3.3
then one or more extension pipes are required.

7.2 Rear Flue

Mark the air duct assembly and the flue duct at the lengths
shown in diagram 7.1 then cut to length, cutting square and
removing any burrs.

7.3 Standard Side Flue

Mark the air duct assembly and the flue duct at the lengths
shown in diagram 7.2 then cut to length, cutting square and
removing any burrs.

7.4 Side Flue With Extensions

Measure the distance from the outside wall to the side of the
boiler casing. With the extensions only joined together (i.e.
without standard flue piece fitted) cut the end nearest to the
boiler, to the dimensions shown in diagram 7.3.

7.5 Flue Assembly

The flue assembly is an entirely push fit design.
The rubber seals should be lubricated prior to assembly.
Remove all burrs from cut pipes.
Diagram 7.4 shows the components supplied in the standard

flue kit.
Having cut the air and flue ducts as described in sections 7.1 -

7.4, assemble the flue as follows: the flue can be assembled
externally and internally by following sections A & C, or entirely
from inside by following sections B & C.

A. External fitting - Fit the rubber sealing collar ‘D’ into the
groove at the outer end of the air pipe ‘B’.

Push the air pipe ‘B’ into the wall until collar ‘D’ is pushed up
against the outside face of the wall.

Ensure that the ‘up’ label on air pipe ‘B’ is at the top, i.e. the tab
protruding into the hole at the outer end of the pipe is uppermost.

B. Internal fitting - Fit the rubber sealing collar ‘D’ into the
groove at the outer end of the air pipe ‘B’.

Fit spacer piece ‘E’ over air pipe ‘B’.
Push the air pipe ‘B’ through the wall until collar ‘D’ is clear of the

outside face of the wall.
Pull the air pipe ‘B’ to ensure that collar ‘D’ is pulled up to the

outside wall face.
Ensure spacer piece ‘E’ is pushed into the wall, see diagram

7.1.
C. Fitting Completion - Fit sealing flange ‘F’ over the air pipe

and against the inside wall face.
From inside fit flue pipe ‘A’ into the air pipe ‘B’ ensuring that the

groove on the outer end engages in the air pipe tab.
Fit the flue pipe spacer ‘C’ over the flue pipe ‘A’ and push inside

air pipe ‘B’.
Attach any extension pieces necessary.

7 Flue Preparation

Diagram 7.3

SIDE FLUE EXTENSION

6554

Y

C

L

BOILER

Y - 483 LEFT FLUE DUCT
Y - 417 RIGHT FLUE DUCT

Y - 493 LEFT AIR DUCT
Y - 427 RIGHT AIR DUCT

OUTSIDE
WALL FACE

SIDE OF
BOILER

AIR DUCT

FLUE
DUCT

125
DIA.
HOLE

Diagram 7.1

X + 196

( AIR DUCT ASSEMBLY)

X + 271

( FLUE DUCT )

X

OUTSIDE
WALL
FACE

Diagram 7.2

SIDE DUCT -STANDARD FLUE

6555

BOILER
MOUNTING
WALL

6505

REAR FLUE

Y + 297 LEFT FLUE DUCT
Y + 363 RIGHT FLUE DUCT

Y + 222 LEFT AIR DUCT
Y + 288 RIGHT AIR DUCT

C

L

BOILER

Y

OUTSIDE
WALL FACE

SIDE OF
BOILER

AIR DUCT

FLUE
DUCT

16

221564F

7.6 Flue Attachment To Boiler

Refer to section 8 and fix the boiler in position prior to completing
the flue installation.

Pull off the wire clip on the flue adaptor pipe inside the boiler, see
diagram 7.5. Push the flue adaptor pipe downwards into the flue
pipe.

Refer to diagram 7.4. Fit rubber dome ‘J’ to the base of the flue
elbow ‘G’ and place securing ring ‘H’ over the elbow to rest
around the bottom flange of the rubber dome.

Fit flue elbow ‘G’ to air pipe ‘B’ and flue duct ‘A’. A small amount
of lubricant can be applied to the rubber seals in the elbow to
facilitate this.

Secure the rubber dome ‘J’ to the top of the boiler with securing
ring ‘H’ and screws provided.

Push the flue adapter pipe up onto the inner duct of the elbow
and secure with wire clip.

Diagram 7.4

6507

Diagram 7.5

6551

GROOVE

TAB

‘A’

‘B’

‘G’

‘H’

‘J’

‘D’

‘E’

‘F’

SCREW

(4 OFF)

‘C’

LABEL

FLUE
ADAPTOR

PIPE

WIRE CLIP

GROOVE

BOILER FLUE
OUTLET PIPE

7 Flue Preparation

17 221564F

Boiler Fixing

Having previously secured the wall mounting jig and hanging
bracket to the wall, lift the boiler into position in the following
manner. To assist in the lifting of the boiler, remove the casing
door.

Lean the top of the boiler slightly to the wall and position just
above the hanging bracket. Allow the boiler to slowly move
downwards until engaged in the hanging bracket.

Slowly swing the base of the boiler to the wall mounting jig
ensuring that the copper tails on the boiler fit into the gas and
water isolation valves on the jig, see diagram 8.1. If necessary
the gas and water isolation valve clamps can be loosened to
ease fitting. Make sure that the isolation valves are secured
with the clamps after making good the connections.

Connect the two electrical connector plugs hanging from the
boiler into the sockets on the wall mounting jig. The white mains
electrical supply socket on the left hand side of the jig and the
black auxiliary electrical socket on the right hand side of the jig.

NOTE: Please refer to condensate connection before
proceeding, see section 9.4.

Attach the flue as described in section 7.6.

BOILER
MOUNTING
FRAME

GAS
ISOLATION
VALVE

Diagram 8.1

CENTRAL
HEATING
RETURN

DOMESTIC
HOT
WATER
OUT

CENTRAL
HEATING
FLOW

DOMESTIC
COLD
WATER
SUPPLY IN

6512

DRAIN
POINT

DRAIN
POINT

GAS
SERVICE
COCK

ALL SLOTS SHOWN IN
CLOSED POSITION

CLAMP

SECURING

SCREW

PRESSURE RELIEF
VALVE PIPE

GAS & WATER ISOLATION VALVES

8 Boiler Fixing

9 Gas, Water, and Condensate Connections

9.1 Gas Connection

The gas supply can be connected from below or through the
wall at the rear of the boiler, the position is shown on the wall
template.

Refer also to section 1.2.
Make the gas supply connection to the gas isolation valve.

Slacken or remove the clamp, as desired, whilst making the
connection. Do not subject the gas isolation valve to heat, see
diagram 8.1.

9.2 Water Connections

Provision is made for the water connections to be made from
below or through an internal wall at the rear of the boiler, the
position is shown on the wall template. Copper tail pieces are
supplied in the wall mounting pack if required.

Flush out the domestic hot water and the heating systems
before connecting to the boiler.

Make the connections to the domestic hot water and heating
systems by way of the isolating valves, see diagram 8.1

Slacken or remove the clamps, as desired, while making the
connections. Do not subject any of the isolating valves to heat.

DOMESTIC
WATER
VALVES

CENTRAL
HEATING
VALVES

DRAIN
POINT TO
FRONT OF
APPLIANCE

18

221564F

Make sure that the drain points on the isolating valves are
positioning towards the front of the boiler, also that the drain and
operating screw heads are accessible.

9.3 Safety Valve Discharge

WARNING: The pipe from the safety valve must not discharge
above an entrance, window or any type of public access area.

A short discharge pipe is supplied loose in the wall mounting
pack. This must be extended, using not less than 15mm o.d.
pipe, to discharge, in a visible position, outside the building,
facing downwards, preferably over a drain.

The pipe must have a continuous fall and be routed to a position
so that any discharge of water, possibly boiling, or steam cannot
create any danger to persons, damage to property or external
electrical components and wiring.

NOTE: To ease future servicing it is advisable to use a
compression type fitting to extend the discharge pipe.

9.4 Condensate Connection

The condensate connection is at the bottom of the boiler to the
left hand side of the wall mounting jig, see diagram 9.1.

The condensate discharge pipe should have a fall of at least 2.5

o

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.

It is recommended that any external condensate drain pipe is at
least insulated and also preferably of larger diameter, to prevent
freezing in adverse weather conditions.

The condensate is discharged periodically in ‘slugs’ by siphonic
action.

Diagram 9.1

5238

CAP

CONDENSATE
DRAIN

SPIGOT

OVER FLOW PIPE

9 Gas, Water, and Condensate Connections

10.1 Supply Cable Connection

THIS APPLIANCE MUST BE EARTHED.
CAUTION: To prevent an induced current from switching the

central heating on, when not required, it is important that the
heating system control cables are separated from the other
mains supply cables.

The boiler requires a permanent mains supply through an
isolator, see section 1.4.

Any heating system controls must not interrupt the permanent
mains electrical supply to the boiler.

Unscrew the mains electrical supply cover plate, situated on the
left hand side of the wall mounting jig, see diagram 10.1.

Remove the mains electrical connector socket from the fittings
pack and push on to the bracket on the left hand side of the wall
mounting jig with the socket pins pointing upwards. Remove the
two securing screws and cover from the socket. Using PVC
cable of suitable length and rating as stated in section 1.4,
connect the mains supply cable to the appropriate terminals of
the plug, see diagram 10.2.

Standard colours are, Brown - Live; Blue - Neutral; Green and
Yellow - Earth.

The electrical mains supply cable outer insulation must not be
cut back external to the connector.

Make the earth cable of a greater length so that if the cable is
strained the earth would be the last to become disconnected.

CAUTION: It is essential that the polarity is correct.

10 Electrical Connections

It is recommended that the condense drain is prefilled by
pouring 250ml (

1

/2 pt) of water into the boiler flue outlet pipe

prior to commissioning, see diagram 7.4.
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 British Gas publication “Guidance notes for the
Installation of Domestic Condensing Boilers” for advice on the
disposal of the boiler condensate.

19 221564F

10.2 Heating System Controls

WARNING: Mains electricity must not be connected to the
black auxiliary control plug.

All heating system controls must be low voltage or potential
free.

It is recommended that the boiler is controlled by a programmer
and room thermostat. A suitable room thermostat is supplied in
the wall mounting pack.

Thermostatic radiator valves may be installed in addition to the
room thermostat.

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

All system controls are wired into the black electrical connector
plug situated on the right hand side of the wall mounting jig.

If electrical controls are being used the links between terminals
should be removed as necessary as shown in diagram 10.3.

If electrical controls are not being used, DO NOT REMOVE the
red and blue links between terminals 1 and 2, and 2 and 3 in the
black electrical connector plug.

10.3 Clock/Timer

An integral clock/timer kit can be supplied as an optional extra.
Refer to the literature supplied with it, regarding fitting.

10.4 Frost Thermostat

This boiler has its own frost protection device to protect the
boiler. Additional frost protection may be required for exposed
pipework. If required, connect a single pole frost thermostat to
the appropriate terminals of the black electrical connector plug
as shown in diagram 10.3.

10.5 Outside Sensor

An outside sensor can be supplied as an optional extra, see
section 11.11. If required, connect to the red and black wires
which are pre-wired to terminals 4 and 5 of the control module.

10.6 Cable and Connector Securing

After completing all the connections to the wall mounting jig
electrical connectors, secure the cables with the covers, using
the screws previously removed.

Connect the boiler connector, and replace the cover plate over
the white mains connector, see diagram 10.4.

10.7 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.

Diagram 10.2

6531

MAINS ELECTRICAL
SUPPLY SOCKET

EARTH

(L) LIVE

(N) NEUTRAL

Diagram 10.1

MAINS ELECTRICAL
COVER PLATE

SECURING
SCREW

6571

BRACKET

Diagram 10.3

6553

FROST THERMOSTAT

ROOM
THERMOSTAT

CLOCK
TIMER

RED LINK

BLUE LINK

Diagram 10.4

APPLIANCE
PLUG

MAINS IN
SUPPLY PLUG

COVER
PLATE

SCREW

WARNING : Mains electricty must not be connected to
the black auxiliary control plug.

6596

10 Electrical Connections

20

221564F

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

11.1 Filling Domestic Water Circuit

Fully open any valves in the domestic water supply to the boiler.
Open the two domestic water isolation valves, slots in line with

the length of the valve, see diagram 8.1.
Open all hot water taps in turn and close them when water flows.

Check for water soundness of the complete domestic water
system.

The water flow rate is regulated to 12 litres/min by a restrictor
fitted into the boiler pipe work.

11.2 Filling the Heating Circuit

Open the two central heating isolating valves, slots in line with
the length of the valve, see diagram 8.1.

Flush, fill and vent the system refering to sections 4.5 and 9.2.
Make sure that the automatic air vents are operating correctly,

see diagram 11.1, and that their black caps are loosely fitted to
allow air to escape.

Diagram 11.1

6549

AUTOMATIC
AIR VENTS

CYLINDER
SECURING
COLLAR

Pressurise the system until the pressure gauge reads at least

1.0bar (14.5lbf/in2), see diagram 1 in Instructions for Use.
Check the heating system and boiler for water soundness.

11.3 Preparation for Lighting

Isolate the boiler from the mains electrical supply.
Test for gas soundness and purge air from the gas supply. Turn

on the gas isolation valve, slot in line with the length of the valve,
see diagram 8.1.

11.4 Initial Lighting

The lighting procedure of the boiler is fully automated. Check
that all external controls are calling for heat. If an integral clock/
timer is fitted check that it is correctly programmed and if
necessary overridden to provide heat.

Turn on the mains electrical supply. After a short delay the
digital display on the fascia should illuminate, see diagram 1 in
Instructions for Use.

The fan should start and after a few seconds the ignition will
commence.

If the burner fails to light the fan will stop and the display will flash

'0' and then '2*'. This indicates the boiler has failed to light,

which initially may be due to air in the gas supply line.

Press the ‘Reset’ button and the boiler will restart, see diagram
1 in Instructions for Use

Flashing digits indicate a fault. Refer to fault finding if any fault
persists, see section 13.

After the burner has lit, the boiler will initially heat up the
domestic hot water cylinder. This will take approximately four
minutes.

After this a pump overrun will operate to ensure that the stored
water temperature is not too high.

After a short period the three way valve will switch to central
heating.

The boiler will continue firing in central heating mode until the
user controls; ie. time clock or room thermostat are satisfied, or
there is a demand for hot water.

11.5 Gas Pressure

The gas valve is factory set and should need no adjustment. It
should be checked that the supply pressure is 20mb when the
boiler is firing at full rate. This can be achieved by turning on
several hot water taps and checking the inlet pressure at the
tapping on the gas valve shown in diagram 11.2. Turn taps off
and disconnect pressure gauge.

NOTE: The burner pressure is altered by the suction of the fan
and is modulated according to demand.

11.6 Testing - Heating System

Check that all remote controls are calling for heat. The boiler will
fire automatically. Fully open all radiator valves, flow control
valve ‘A’ and additional bypass valve ‘B’ if fitted, see diagram

4.2.
Balance the radiators as required and if fitted adjust valve ‘A’ to

give the required system differential. Turn off all radiators that
can be shut off by the user and adjust the boiler bypass if
necessary to achieve less than the maximum differential allowed
of 20°C across flow and return.

If this is not possible, a separate system bypass must be fitted
and adjusted to achieve less than maximum differential. Refer
to section 4.3 and diagram 4.2.

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 11.2.

Lock or remove the handles from controls valve ‘A’ and bypass
valve ‘B’ if fitted to prevent unauthorised adjustment.

11.7 User Control Door - Fitting

Take the control door, which was removed from the top of the
boiler carton and fit the the two brass lugs. Push the lugs into the
slots at the bottom of the fascia to engage, see diagram 11.3.

11.8 User Controls and Options

The Energysaver Combi has a multifunctional single digit
display and two control buttons labelled ‘Mode’ and ‘Reset’, see
diagram 1 in Instructions for Use.

The ‘Reset’ button is used to restart the boiler after a fault
condition has occurred, ie. ignition failure, low water pressure or
high water temperature.

The ‘Mode’ button allows the user to view the operating conditions
of the boiler, or if necessary change the domestic or central
heating temperatures to a preferred setting. The boiler is factory
pre-set to supply Domestic hot water up to 65°C and central
heating up to 70°C.

11 Commissioning

21 221564F

Diagram 11.2

6532

PRESSURE TEST
POINT

ELECTRICAL

CONNECTIONS

ELECTRICAL

CONNECTIONS

PROTECTIVE CAP

Repeated pressing of the 'Mode' button gives the display
sequence shown in diagram 11.4.

If a different option is required, repeatedly press the ‘Mode’
button until the required symbol is shown, and then press and
hold the ‘Mode’ button for two seconds. The decimal point will
flash to confirm selection.

Note: If left the display reverts to show boiler temperature after
approximately two minutes.

Temperature Display

The boiler normally shows the operating temperature of the unit
on the digital display. However, because the display consists of
only one digit, temperature is represented in blocks of ten
degrees as follows.

CONTROL
DOOR

DISPLAY TEMPERATURE RANGE (°C)

0 Min - 5

1 6-15
2 16 - 25
3 26 - 35
4 36 - 45
5 46 - 55
6 56 - 65

7 66 - 75
8 76 - 85
9 86 - Max

6566

Diagram 11.3

6533

BRASS
LUGS

The decimal point after the digit signifies that the boiler is firing.
This information is also supplied on the inside of the control

door.

11 Commissioning

Temperature Options

There are four domestic hot water and four central heating
options to choose from. These options are shown on the digital
display by repeated pressing of the ‘Mode’ button. The sequence
is shown in diagram 11.4. The selected options are indicated by
a flashing decimal point.

Only one domestic hot water and one central heating option can
be selected at any one time.

For adaptive control, see section 11.10.

22

221564F

Control Options

There are two control options available: Normal mode and
Holiday mode, see diagram 11.4.

Normal mode uses the domestic hot water and central heating
temperatures selected.

Holiday mode shuts down the domestic hot water and central
heating. However, frost protection and pump exercise
programme remain active. To resume normal operation after a
holiday period, select ‘Normal Mode’,

.

Note: If an external frost thermostat is fitted ‘Holiday Mode’
should not be selected during periods of cold weather.

Alternatively select setting to turn off the domestic hot
water and turn the central heating off at the programmer or

reduce the room thermostat temp to a low setting.

11.9 Servicing Options

There are four options available to the service engineer,which
are not to be used by the user, see diagram 11.4. They are as
follows.

Installation Mode

This allows interrogation of the appliance by an authorised
engineer, via the connection of a P.C.

After using the installation mode, normal operation of the
appliance can be resumed by reselecting
'Normal mode', .

Operating Function

The current function that the boiler is performing is shown by a
number with a flashing decimal point, see table below.

DISPLAY ACTION

No demand.

Boiler fan is purging the system.

Ignition phase.

Boiler is suppyling central heating.

Boiler is supplying domestic hot water.

Waiting for the fan to run up to speed.

Boiler is off after reaching temperature.

Central heating pump overrun.

Domestic hot water pump overrun.

Boiler safety shut down.

OPERATING FUNCTION

Minimum Input Lock

This function allows the service engineer to lock the appliance
into delivering minimum heat input to enable accurate combustion
analysis.

Maximum Input Lock

This function allows the service engineer to lock the appliance
into delivering maximum heat input to enable accurate
combustion analysis.

See section 12.6 for details of checking combustion.
Both input locks are not permanent and revert to normal

operation after approximately 15 minutes. The boiler can be
manually reverted at any time by pressing the ‘Reset’ button.

NOTE: If left the display automatically reverts to display
temperature after approximately two minutes.

11.10 Adaptive Control

Adaptive Control is an advanced control feature that requires
the interaction of a room thermostat. It is used in two out of the
four central heating options and allows the boiler to optimise the
heat output. This enables the boiler to operate at much lower
temperatures and hence be more fuel efficient.

If a room thermostat is not fitted when using these modes the
boiler will revert to standard modulation at the temperatures
given in diagram 11.4.

NOTE: When the boiler fires from cold with the adaptive control
active, it fires at low rate for ten minutes before ramping up to
full rate.

For details of wiring in a room thermostat refer to section 10.2
and diagram 10.3.

11.11 Outside Sensor

If an outside sensor is fitted the boiler adjusts the flow temperature
to compensate for variations in external temperature. Only two
central heating options are available which are different to those
in diagram 11.4, these are:

The outside sensor optimises the boiler
flow temperature to suit demand. Normal on/off control is
retained but a room thermostat is required. This is the preferred
option.

For use in systems with a programmer but no room
thermostat. Sets the boiler flow temperature depending on
external temperature. During “off” periods on the programmer
the flow temperature is reduced by 10OC.

11.12 Operating Sequence

Refer to diagram 11.4 and press the ‘Mode’ button until the
Operating function is displayed.

6574

11 Commissioning

23 221564F

to

to

to

BOILER
TEMPERATURE (Decimal Point illuminated means boiler is firing)

NOTE:- The SYMBOL (flashing decimal point) indicates the selected options

For use with a supplementary
hot water cylinder

Holiday mode

Operating function

Press Mode -

Press Mode -

Press Mode -

Press Mode -

Press Mode -

Press Mode -

Press Mode -

Press Mode -

Press Mode -

Press Mode -

Press Mode -

Press Mode -

Press Mode -

Press Mode -

Press Mode

65 C

O

55 C

O

OFF

Domestic hot
water options
(select one only)

55 C with adaptive control

O

70 C with adaptive control

O

85 C

O

85 C with continuous
pump operation

O

Central heating
options
(select one only)

Normal mode

Control options

Servicing options

Minimum input lock

Installation mode

Maximum input lock

Returns to temperature display

Diagram 11.4

6563

Sequence Chart for Digital Display

11 Commissioning

24

221564F

The operating sequence of the appliance can be checked
against the following two tables.

11.13 Pump Exercise Program

After a power cut or every 24 hour in holiday mode the three way
valve will switch and the pump will run for one minute to prevent

DISPLAY ACTION
(Operating
function)

No demand.

Create demand by turning on
a hot water tap.

Pump and fan start.

Fan running up to speed.

Gas valve opens
and ignitor sparks for 3 seconds.
Burner ignites.

Hot water supplied to thermal
store.

End of hot water demand
i.e. hot water turned off.

Burner modulates to bring thermal
store to correct temperature.

Burner shuts down and
pump overrun commences.

No demand.

DOMESTIC HOT WATER SEQUENCE TABLE

6573

11 Commissioning

DISPLAY ACTION
(Operating
function)

No demand.

Create demand by switching on
timer or room thermostat.

Three way valve switches to
central heating
(approx. 15 seconds).

Pump and fan start.

Fan running up to speed.

Gas valve opens
and ignitor sparks for 3 seconds.
Burner ignites.

Burner runs at ignition rate (70%)
for 10 seconds.
Rate drops to minimum for
60 seconds.
Input adjusts according to heating
option selected.

End of heating demand
i.e. room thermostat satisfied.

Burner shuts down and timed
pump overrun commences.

No demand.
3 way valve switches back
to domestic position
(approx 15 seconds).

CENTRAL HEATING SEQUENCE TABLE

6572

the components from sticking. This will also occur during
normal operating if there is no domestic or central heating
demand for more than 24 hours.

11.14 Frost Protection

During periods of no demand the boiler is protected by a frost
protection procedure. If the heating outlet temperature falls to
7°C the pump will start. If the heating outlet temperature
continues to fall to 3°C the burner is ignited. The burner is
extinguished when the heating outlet reaches 10°C, the pump
will run for a further 15 minutes. This function primarily protects
only the boiler.

If an additional frost thermostat is fitted, switching of this will
operate the boiler.

11.15 Instruct the User

Instruct and demonstrate the lighting procedure and advise the
user on the safe and efficient operation of the boiler.

Instruct on and demonstrate the operation of any heating
system controls.

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 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 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.

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 flue terminal in
cool weather. This is due to the high efficiency and hence low
flue 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 would not be operable.

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

25 221564F

12.1 General

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 sufficient.

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

Measurement of the products of combustion can be achieved
by connection of a probe to the flue elbow or alternatively to the
sample point at the base of the flue outlet pipe inside the boiler,
see diagram 12.1.

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 isolation valve, see
diagram 8.1.

All routine servicing requirements can be achieved by the
removal of the front door only. To remove, simply lower the
control door and remove the two screws at the bottom of the
front door.

Unless stated otherwise any part removed during servicing
should be replaced in the reverse order to removal.

Servicing should always include the removal of any debris from
the condensate pipe and siphon.

After completing any servicing of gas carrying components,
ALWAYS test for gas soundness and carry out a functional test
of the controls.

12.2 Combustion Chamber and Heat
Exchanger

The Combustion Chamber and Heat Exchanger do not require
cleaning during routine servicing. See section 12.11 for major
servicing.

12.3 Burner and Fan

Undo the union nut on the injector tube. Lift the tube clear of the
injector on the gas valve and then twist the tube and pull
downwards to disengage from the fan inlet flange, see diagram

12.2.
Remove Air pressure switch tube, see diagram 12.2.
Remove spark plug lead, see diagram 12.3.
While supporting the fan, remove the wing nut and screw and

pull out the fan securing plate, see diagrams 12.3 & 12.4.
Gently lower the fan and burner assembly out of the combustion

chamber.
Disconnect the electrical lead from the fan.
Inspect the burner for any signs of damage.
The burner can be cleaned if necessary by washing in warm

soapy water and rinsing with clean water. DO NOT use wire or
sharp instruments to clean the holes of the burner.

Clean the inlet holes of the fan inlet flange with a soft brush or
vacuum cleaner, see diagrams 12.2 and 12.5.

Examine the fan inlet and outlet seals and replace if necessary.
When refitting the fan securing plate, ensure that the dimples

are uppermost and that the fork on the plate engages onto the
ledge on the Heat Exchanger, see diagram 12.6.

When refitting the injector tube make sure the ‘O’ ring seal is
fitted.

12.4 Spark Electrode

Remove the spark plug lead and two securing screws. Withdraw
the spark electrode and viewing window from the combustion
chamber, see diagram12.3.

Inspect the tips for damage.
Clean away any debris and check the spark gap is 3.5

+

0.5mm,

see diagram 12.7.
Check the electrode gasket for signs of leakage and replace if

necessary.

12.5 Condensate Drain

Place a container beneath the condensate drain cap.
Carefully remove the cap at the base of the condensate drain

trap, see diagram 9.1.
Remove any solids found.
Check for any debris in the outlet pipe of the condensate drain

and clean as necessary.
When refitting the cap ensure that a water tight seal is achieved.
Fill the condensate trap as recommended in section 9.4.

Diagram 12.2

6528

Diagram 12.1

6527

FLUE ELBOW

PROBE

POSITION

FLUE
OUTLET
PIPE

“O” RING SEAL

INJECTOR
TUBE

AIR
PRESSURE
SWITCH TUBE

INJECTOR

VENT
PIPE

12 Servicing

FAN INLET
FLANGE

26

221564F

SPARK GAP

3.5

+

0.5mm

Diagram 12.7

6550

WATER
INLET
FILTER

Diagram 12.8

6552

SPARK
ELECTRODE
SECURING
SCREW (2 OFF)

ELECTRODE
GASKET

SPARK
ELECTRODE

SECURING
PLATE

WING
NUT

LEDGE

Diagram 12.3

6560

Diagram 12.4

6526

Diagram 12.6

6545

Diagram 12.5

6544

FAN

SPARK PLUG
LEAD

SECURING
PLATE

FAN

FAN INLET
FLANGE

SECURING
PLATE

Ensure the securing plate forks
are supported on the ledge.

SPARK
ELECTRODE
SECURING
SCREW (2 OFF)

THERMOSTATIC
MIXER VALVE

Fan removed for clarity

12 Servicing

27 221564F

12.6 Combustion Check.

Connect a CO2 combustion analyser to the test point on the flue
elbow if fitted, or alternatively to the sample point at the base of
the flue outlet pipe inside the boiler casing, see diagram 12.1.

Turn on the gas isolation valve, see diagram 8.1.
Turn on the electricity supply.
The boiler should fire automatically, but if there is no demand for

heat open a hot water tap to create a demand.
Repeatedly press the 'Mode' button on the boiler fascia until the

symbol

appears.

Press and hold the 'Mode' button for greater than one second
until the decimal point is flashing on the display.

The boiler is now locked at minimum input.
Allow the boiler to stabilise for a few minutes and then check the

CO2 value. See Table 1.
If adjustment proves necessary then proceed as follows.
NOTE: The CO2 value can only be adjusted at minimum input.
Any adjustment to the gas valve should only be carried out by

a qualified person.
Remove the protective cap from the Gas Valve. See diagram

11.2.
Turn the adjuster until the correct CO

2

value is attained.

To check the combustion at full rate repeatedly press the mode

button on the boiler fascia until the symbol

appears. Press

and hold the mode button until the decimal point on the display
flashes.

The boiler is now locked at maximum input.
If necessary several hot water taps should be turned on to

deliver maximum flow rate to prevent the boiler from shutting
down for overheat protection.

Check the combustion levels of CO and CO

2

.
If the combustion is excessive, see fault finding section 13.3.
NOTE: The CO

2

level should not be adjusted in maximum input

lock mode.
Press the Reset button to remove the minimum or maximum

input lock. Replace caps on sample point and gas valve.

12.7 Cold Water Inlet Filter

If the water flow rate through the appliance has reduced it may
be necessary to clean or replace the water inlet filter.

Turn off the electrical supply to the boiler.
Drain the Domestic Hot Water circuit by closing the cold water

isolation valve on the wall mounting jig, see diagram 8.1.
Open one or more hot water taps to drain the hot water circuit.
Undo and remove the drain screw on the cold water inlet valve

and drain away any remaining water.
Undo the connecting nuts on either end of the water inlet pipe

and remove the pipe from the boiler.
Remove the filter situated in the end of the cold water inlet pipe,

see diagram 12.8.
Clean the filter, inspect and renew if necessary.
Replace the filter into the cold water inlet pipe. Replace the drain

screw in the cold water isolation valve. Replace the water inlet
pipe and tighten the unions.

Open the cold water isolating valve and test the Domestic Hot
Water circuit for soundness.

12.8 Casing Panel Removal

During major servicing or replacement of parts it may be
necessary to remove the boiler side panels to gain access.

Remove the front door and the control door. See section 11.7.
To remove a side panel undo and remove the four screws

securing the lower panel brackets to the boiler.
Remove the brackets along with the control door.
Undo and remove the four screws securing each side panel to

the boiler, two at the bottom and two at the top.
Pull the panel out at the bottom and off at the top of the boiler.

12.9 Draining of Boiler Heating Circuit

Drain down the Heating Circuit of the boiler only, by closing the
heating flow and return isolating valves on the wall mounting jig,
see diagram 8.1.

NOTE: These valves are closed when the slots are at right
angles to the direction of flow.

Lift the head of the pressure relief valve on the underside of the
boiler by twisting and allow the boiler circuit to drain. Complete
draining by removing the drain screws from the isolating valves
and drain the water into a suitable receptacle.

After servicing or replacing parts, open the heating flow and
return isolating valves and refill, vent and pressurise the heating
circuit. See section 11.2.

Check for leaks.

12.10 Draining of Boiler Hot Water Circuit

Drain the Domestic Hot Water circuit by closing the cold water
isolation valve on the wall mounting jig.

Open one or more hot water taps to drain the hot water circuit.
Undo and remove the drain screw on the cold water isolation

valve and drain away any remaining water, see diagram 8.1.
After servicing or replacing parts, replace the drain screw, open

the cold water isolation valve and slowly open a hot water tap
to remove air. Close the hot water tap and check for any leaks.

12 Servicing

28

221564F

12.11 Heat Exchanger - Major Servicing

Refer to Fault Finding sections 13.1, (fault code 0 and 8.) and

13.4 before carrying out a major service of the heat exchanger.
If it is suspected that the heat exchanger has become partially

blocked internally, proceed as follows.
Remove the burner and fan as described in section 12.3.
Remove the wire clip from the internal flue adaptor, see diagram

7.5.
Push the adaptor pipe downwards into the boiler flue pipe,

disengaging it from the flue elbow.
Remove the boiler flue pipe.
Check for any blockage in the boiler flue pipe and remove any

debris.
Check for any blockage in the casting flue outlet orifice and

remove any debris.
Place a suitable container below the condense drain and

remove the cap. See section 12.5.
Using a suitable spanner, remove the heat exchanger top panel

nuts, see diagram 12.9. Take care when removing the nuts not
to drop them behind the heat exchanger.

Carefully prise open the boiler top, making sure that the washers
are retained on removal.

Replace the boiler flue pipe.
Place a water hose into the top of the heat exchanger, taking

care not to damage the insulation to the rear, see diagram

12.10.
Thoroughly flush the heat exchanger from above and collect the

water and any debris in the container beneath the condense
drain.

Flush the heat exchanger until the water appears clear at the
condense drain.

Check the condition of the heat exchanger top gasket and
replace if necessary.

Rebuild the boiler.
Repeat the combustion test as detailed in section 12.6.
If the combustion is still unacceptable then the heat exchanger

will need to be replaced. Refer to section 14.21 and remove the
heat exchanger.

HEAT
EXCHANGER

Diagram 12.9

6534

HOSE

Diagram 12.10

6535

TOP PANEL
NUTS (6 OFF)

Air Vent Pipe
removed for clarity

INSULATION

Air Vent Pipe
removed for clarity

12 Servicing

29 221564F

6576

Schematic Wiring Diagram

KEY

Red r
Black b
Blue bl
Brown br
Green gr
Yellow y
Green/Yellow g/y
White wh
Orange or
Grey gy

g/y

g/y

g/y

br

bl

bl

br

Ribbon cable

X8

X7

FLOW N.T.C.
THERMISTOR

RETURN N.T.C.
THERMISTOR

HOT WATER N.T.C.
THERMISTOR

OUTSIDE
SENSOR

P.C INTERFACE

CONTROL PANEL

AUTOMATIC CONTROL MODULE

FLAME IGNITION AND
ONISATION ELECTRODE

THREE WAY
VALV E

RESISTOR
220Ω / 7W

230V/50Hz
MAINS PLUG

CHASSIS
EARTH POINT

LOW VOLTAGE PLUG
Room thermostat
Clock/timer
Frost thermostat

WATER PRESSURE
SWITCH

GAS CONTROL
VALVE ES80

PUMP

INTERNAL
FUSES

X1-1
X1-2
X1-3
X1-4
X1-5

F1=2AF

X2-1

F3=3AT

F2=2AF

X2-2

X2-3

X2-4

X2-5

X2-6

X3-1

bbgrrb

whblrborwhrgrr/whgyb

y

br

X3-2

X3-3

X3-4

X3-5

X3-6

X2-7

X2-8

X2-9

X2-10

X2-11

X2-12

X2-13

b

b

1 gr

3 gr

D.C. FAN

AIR
PRESSURE
SWITCH

bl r/wh

r/wh

br

y

bl

r

GAS
CONTROL
VALVE
ES100

13 Fault Finding

Diagram 13.1

30

221564F

13 Fault Finding

13.1 Digital Display - Fault Codes

If a fault has occurred during operation of the boiler the display
will start flashing.

Two numbers will alternate to show what type of fault has
occurred.

The second number has a decimal point after it.

Fault Code = 0 and 0.

There is a flame signal without there being a flame present.
Press the reset button.
If the fault recurs, check the ignition electrode and wire.
Check to see if there is 24V a.c. on the gas valve.
If there is 24V a.c. at the gas valve then replace the Automatic

control module, see section 14.4.
After replacing the Automatic Control Module, press the “reset”

button and check that the boiler functions correctly. Check that
flames extinguish correctly and that after heating demand is
complete there is not 24V a.c. present at the gas valve.

Fault Code = 0 and 2.

There is no flame ionisation.
This fault code may appear on commissioning the boiler and

may simply due to the presence of air in the gas line.
Press the reset button and the ignition phase will be repeated.
If the problem recurs, then proceed as follows:
Check that the gas supply to the boiler is turned on.
Check that during the ignition phase there are sparks present at

the electrode.
Check that the spark gap of the electrode is correct, see section

12.4.
Check that the resistance of the ignition wire is less than 1000

ohms. If the resistance is too high, change the lead. See section

14.3.
Re-check to see if sparks are present at the electrode. If not

check the electrode and change if necessary, see section 14.2.
If there is still no spark at the electrode then the Automatic

Control Module needs replacing, see section 14.4.
If the burner lights but the flame is not detected, the CO

2

level
may be too low to sustain combustion. Refer to section 12.6. Try
turning the adjustment screw clockwise to increase the CO

2

content. If the burner flame is still not detected, then the
Automatic Control Module needs replacing. Refer to section

14.4.
If the gas valve setting has been adjusted in any way, the CO

2

value must be reset to the correct value. See section 12.6.

Fault Codes = 0 and 3., 0 and 5., 0 and 6., 0 and 7., 1 and

1

., 1 and 3., 1 and 4., 1 and 5.,1 and 6., 1 and 7., 4 and 1., 4 and

2

. and 6 and 0.

There is an internal fault in the Automatic Control Module.
Try pressing the “reset” button.
If the fault is not cleared, the Automatic Control Module should

be replaced. Refer to section 14.4.

Fault Codes = 0 and 4.

Power supply has been interrupted.
This fault code may appear on first commissioning the boiler, or

if the power is interrupted while the boiler is in operation.
Press the “reset” button.

If the fault code is not removed then an internal fault has
occurred in the Automatic Control Module.

Refer to section 14.4 and replace the module.

Fault Code = 2 and 4.

The heating flow thermistor and heating return thermistor are
connected the wrong way round.

Exchange the thermistor positions or their wiring.

Fault Code = 3 and 0.

There is excessive temperature difference between the flow
and return thermistors.

Check that the pump is functioning correctly.
Check that the system is not air locked.
Check that the flow rate through the installation is high enough.

Refer to section 4.3.

Fault Code = 3 and 1.

The heating flow thermistor is short circuited.
Check the wiring between the thermistor and the Automatic

Control Module for a short circuit.
If the wiring is sound, change the thermistor. Refer to

section 14.8.

Fault Code = 3 and 2.

The heating return thermistor is short circuited.
Check the wiring between the thermistor and the Automatic

Control Module for a short circuit.
If the wiring is sound, change the thermistor. Refer to

section 14.9.

Fault Code = 3 and 6.

The heating flow thermistor is too resistant.
Check that the wiring has not become disconnected
If the wiring is sound, change the thermistor. Refer to

section 14.8.

Fault Code = 3 and 7.

The heating return thermistor is too resistant.
Check that the wiring has not become disconnected.
If the wiring is sound, change the thermistor. Refer to

section 14.9.

Fault Code = 0 and 8.

The Air pressure switch has not closed.
Check that the air pressure switch is functioning correctly.

Switch off the electrical supply to the boiler.
Remove the sensing pipe from the fan elbow and gently suck on

the pipe. The air pressure switch should click shut. Immediately
crimp the sensing pipe and note whether the air pressure switch
holds pressure. A new air pressure switch is required if under
these conditions the switch drops to open circuit within a few
seconds of crimping the pipe. See section 14.22 for replacement.

Reconnect the sensing pipe to the fan elbow and switch on the
electric mains supply. If the boiler does not fire check the
following.

Check that the condense drain is not blocked and backing up
into the heat exchanger. See section 12.5 for instructions on
cleaning.

Check for any obstruction to the flue system internally.
Check the fan and burner cleanliness as in section 12.3.

31 221564F

If after checking all previous points the error code is still present,
this suggests that the heat exchanger has become partially
blocked. See section 12.11 for major service of heat exchanger.

Fault Code = 2 and 8.

The fan is stationary or there is no fan speed signal.
Check the wiring to the fan.
Check the fan and replace as necessary. See section 12.3 for

fan removal.

Fault Code = 2 and 9.

The fan is stationary and open circuit.
Check the wiring to the fan.

Fault Code = 1 and 2.

There is insufficient water pressure in the heating circuit.
Check that there is sufficient water pressure and adjust if

necessary to 1.5 bar. Press the “reset” button. If the fault
persists check the water pressure switch for continuity. If it is
open circuit then replace the water pressure switch, referring to
section 14.17.

If the water pressure switch is OK, check the 24V a.c. fuse on
the Automatic Control Module (3.15A).

Fault Code = 1 and 8.

The heating flow thermistor is detecting a temperature in
excess of 100°C.

Check that the pump is functioning correctly.
Check that the system is not air locked.
Check that the flow rate through the installation is high enough.

Refer to section 4.3.

Fault Code = 1 and 9.

The heating return thermistor is detecting an excessive
temperature.

Check that the pump is functioning correctly.
Check that the system is not air locked.
Check that the flow rate through the installation is high enough.

Refer to section 4.3.

Fault Code = 2 and 5.

The rate of temperature rise measured by the heating flow
thermistor is too high.

Check that the pump is functioning correctly.
Check that the system is not air locked.
Check that the flow rate through the installation is high enough.

Refer to section 4.3.

13.2 Central Heating

If the central heating fails to operate, or the temperature
provided is poor, check the following:

Check that all external controls are calling for heat.
Check that the boiler controls are set correctly, see section 11.

Increase temperature or return to 'Normal mode'

,

if necessary.
If there is still a problem, check that no domestic hot water taps

are dripping. A dripping tap can prevent the boiler from
operating in the central heating mode. Repair any leaking taps

as necessary.

13.3 Thermistor Characteristics

All three thermistors used on the boiler can be checked for
accuracy against the chart below if their performance is suspect.

13 Fault Finding

Temperature ˚C Resistance (Ohms)
0 35400
10 22500
20 14700
25 12000
30 9835
40 6712
50 4672
60 3311
70 2388
80 1749
90 1300
100 980
110 749

NOTE: That there is no error message displayed for a fault
involving the Domestic Hot water thermistor.

The performance of the thermistor should be checked both at
hot and cold temperatures.

13.4 Combustion

If the combustion CO2 measured during servicing in section

12.6 is too high and cannot be adjusted, or the CO levels
measured at full rate are unacceptable, then the following
possibilities should be investigated and cured.

A. Check the flue system has been correctly installed and that
both air and flue ducts are unobstructed internally, see section

7.5.
B. Ensure that correct terminal clearances are observed and

that product recirculation is impossible, see section 3.3.
C. Ensure that the condensate drain is not blocked. Refer to

section 12.5 for cleaning of the condensate drain and section

14.23 for removal if faulty.
D. Check the condition of the burner and clean or replace as

directed in section 12.3.
E. Check and clean the air inlet to the fan and check that the

seals are in good condition as directed in section 12.3.
F. If after checking all previous points the heat exchanger may

have become partially blocked, see section 12.11 for major
servicing of the heat exchanger.

13.5 Operating Procedure

Refer to section 11.12 if necessary to check for correct
operation of the central heating and domestic hot water.

32

221564F

14.1 General

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

Before replacing any parts the boiler should be isolated from the
mains electric supply and the gas should be turned off at the
service cock on the boiler, see diagram 8.1.

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

After replacing any parts always test for gas soundness 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, see section 12.1.

14.2 Spark Electrode

Replace the spark electrode as described in section 12.4.

14.3 Ignition Lead

Pull the spark plug style connector off the spark electrode and
the spade connector connected to the top of the grey ignition
coil.

14.4 Automatic Control Module

Pull the spark plug style connector of the ignition lead off the
spark electrode.

Carefully remove the ribbon wire from the display connection on
the front face of the unit.

Undo and remove the retaining screw from the top corner of the
module.

Pull the Automatic control module forwards and upwards out of
its bracket and remove the electrical connections from the
underside of the module.

Remove the ignition lead from the module and push onto
replacement unit.

Note that the electrical connections are unique to prevent
incorrect fitting.

The Ribbon wire connection must be fitted to the lower socket
on the module marked ‘DISPLAY’.

14.5 Three Way Valve Head

Refer to diagram 14.1.
The three way valve head can be replaced as a separate item

to the body if necessary.
Depress the location button on the front of the unit.
Twist the valve head top towards the front of the boiler and

remove from the body.
Remove the electrical plug.
The replacement unit must be offered to the body in a rotated

position and pushed to the upright position on the valve body.

14.6 Three Way Valve

Refer to section 12.9 and drain the boiler heating circuit.
Remove the three way valve head as described in section 14.4.
Disconnect the Central Heating return pipe from the water cock

and loosen the clamp, see diagram 8.1.
Remove the two screws from the return pipe flange beneath the

boiler.

Remove the gas pipe.
Remove the domestic hot water pipe.
Undo the left hand nut from the bypass valve, see diagram 4.3.
Remove the pump. See section 14.14.
Undo the compression fittings on the three way valve body, pull

the return pipe down and remove the valve.
Fit the replacement valve and replace pipework.
Open the isolating valves on the flow and return connections

and refill, vent and pressurise the boiler.
Check for leaks.

14.7 Domestic Hot Water Thermistor

Refer to diagram 14.2.
Remove the three way valve head as described in section 14.5.
Remove the thermistor retaining clip.
Pull the thermistor downwards and out of its pocket.
Unclip the connecting plug and remove the thermistor.
Fit replacement thermistor ensuring that it is pushed fully into

the pocket and secure with the retaining clip.
Note that the use of a heat sink compound is not required.
Carry out a functional test of the controls.

14.8 Heating Flow Thermistor

Refer to diagram 14.3.
The heating flow thermistor is situated on the front of the

combustion chamber directly above the spark electrode.
Remove the electrical connections from the thermistor.
Undo and remove the screw and securing bracket.
Fit the replacement thermistor using the heat sink compound

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

14.9 Heating Return Thermistor

Refer to diagram 14.4.
The heating return thermistor is located on the pipe running

from the pump to the heat exchanger.
Remove the thermistor clip by pulling it forwards from beneath

the pipe.
If this thermistor clip is tight it may be necessary to remove the

pump for easier access. See section 14.14.
Remove the thermistor and clip from the boiler.
Disconnect the electrical connections from the thermistor.
Push the thermistor out of its clip.
Push the replacement thermistor into the clip and apply heat

sink compound supplied.
Ensure that the thermistor is correctly located on the flat on the

return pipe and push the thermistor clip into place.
Note that the polarity of the wiring to thermistors is unimportant.

14.10 Gas Injector

Remove the injector pipe as described in section 12.3.
Undo and remove the injector from the outlet of the Gas valve,

see diagram 12.2.
Fit replacement injector into gas valve using a suitable sealant.
Do not over tighten.

14 Replacement of Parts

33 221564F

14.11 Gas Valve

Remove the injector pipe as described in section 12.3.
Remove the gas injector as described in section 14.10.
Remove the electrical connections from the gas valve, see

diagram 11.2.
Undo the gas pipe nut from beneath the base panel.
Undo and remove the two securing screws from beneath the

base panel.
Remove the gas valve.
After replacing the gas valve the combustion CO

2

will need to

be checked and adjusted if necessary, see section 12.6.

14.12 Fan

Remove fan as described in section 12.3.

14.13 Burner

Remove fan and burner as described in section 12.3.

14.14 Pump

Refer to section 12.9 and drain the boiler heating circuit.
Undo the pump union nuts.
Unscrew the electrical cover from the pump and remove wiring.
Fit the new pump and refill, vent and pressurise the boiler.
Check for leaks.

14.15 Pressure Relief Valve

Refer to section 12.9 and drain the boiler heating circuit.
Undo the pressure relief valve unions and remove from the

pipework.
Fit new pressure relief valve.
Refill, vent and pressurise the boiler.
Check for leaks.

DOMESTIC HOT
WATER
THERMISTOR

6546

THREE WAY
VALVE HEAD

Diagram 14.1

6530

LOCATION
BUTTON

Diagram 14.3

6568

Diagram 14.2

HEATING FLOW
THERMISTOR

THERMISTOR
RETAINING CLIP

IMPORTANT NOTE:- The thermistor will
fall out of the pocket if the restraining clip
is not fitted as shown.

POCKET

ELECTRICAL
CONNECTION

(2 OFF)

SCREW

SECURING
BRACKET

14 Replacement of Parts

34

221564F

Diagram 14.4

6567

HEATING RETURN
THERMISTOR

THERMISTOR
CLIP

ELECTRICAL
CONNECTION

(2 OFF)

14.16 Pressure Gauge

Refer to section 12.9 and drain the boiler heating circuit.
Undo the union to the return pipe.
Push the pressure gauge out of the controls fascia while

depressing the retaining lugs behind the fascia, see diagram

14.5.
When replacing the gauge, ensure that the location pin engages

in the slot in the fascia.
Refill, vent and pressurise the boiler.
Check for leaks.

14.17 Low Water Pressure Switch

Refer to section 12.9 and drain the boiler heating circuit.
The Low Water Pressure Switch is located on the boiler flow

pipe directly below the heat exchanger.
Remove the automatic control module, see section 14.4.
Remove the condense trap vent pipe by twisting out of the trap

body, see diagram 12.2.
Disconnect the electrical connections from the switch.
Using a 27mm spanner, remove the switch from the flow pipe,

see diagram 14.6.
Fit the new Low Water Pressure Switch using suitable sealant

on the threads.
Refill, vent and pressurise the boiler.
Check for leaks.

14.18 Expansion Vessel

Refer to section 12.9 and drain the boiler heating circuit
Undo the coupling at the base of the vessel.
While holding the vessel undo the securing bolt on the top panel

of the boiler. Remove the expansion vessel from the boiler
taking care not to lose the securing bolt spacer from the top of
the unit.

Fit the replacement unit ensuring that the securing bolt spacer
is in position and the securing bolt passes through it.

Refill, vent and pressurise the boiler.
Check for leaks.

14.19 Thermostatic Mixer Valve

Refer to section 12.10 and drain the boiler hot water circuit.
From below the boiler base plate, remove the gas pipe and

remove both cold and hot water pipes from the thermostatic
mixer valve.

From above the boiler base plate remove the three way valve
head. See section 14.5.

Undo both hot and cold water connections to the cylinder.
While holding the thermostatic mixer valve undo the two

hexagonal bulkhead connectors, see diagram 14.7.
Fit new valve.
Open the cold water inlet valve.
Check for leaks.

14.20 Hot Water Cylinder

To remove the hot water cylinder it is necessary to drain down
the boiler heating and hot water circuits.

Refer to section 12.9 and drain the boiler heating circuit.
Refer to section 12.10 and drain the boiler hot water circuit.
The right hand casing panel should be removed as described in

section 12.8.
Remove the expansion vessel as described in section 14.18.
Remove the three way valve as described in section 14.6.
Remove the domestic hot water thermistor as described in

section 14.7.
From above the boiler remove the cylinder automatic air vent,

see diagram 11.1.
Remove the cylinder securing collar, see diagram 11.1.
Remove the automatic air vent non- return valve from the top of

the boiler and temporarily replace the cylinder securing collar.
Undo the thermostatic mixer valve connections to the cylinder.
Remove the thermostatic mixer valve, see section 14.19.
Undo the cylinder flow pipe connection from the bottom left

hand side of the cylinder.
While holding the cylinder in place, remove the cylinder securing

collar on top of the boiler.
Lean the cylinder forwards and lift upwards, disengaging the

location studs at the rear and the cylinder flow pipe connection.
Fit the replacement cylinder ensuring its fitting on the location

studs at the rear of the appliance.
When refitting the automatic air vent non - return valve, a

suitable thread sealant must be used.
Open the isolating valves of both heating and hot water circuits,

refill, vent and pressurise the heating circuit.
Check for leaks.

14.21 Heat Exchanger

Refer to section 12.9 and drain the boiler heating circuit.
Refer to Section 12.10 and drain the boiler hot water circuit.

14 Replacement of Parts

35 221564F

The right hand casing panels should be removed as described
in section 12.8.

Remove the gas valve as described in section 14.11.
Remove the fan and burner as described in section 12.3.
Remove the central heating flow thermistor as described in

section 14.8.
Remove the ignition electrode as described in section 12.4.
Remove the pump as described in section 14.14.
Remove the hot water cylinder as described in section 14.20.
Remove the automatic control module as described in section

14.4.
Remove the air pressure switch as described in section 14.22.
Remove the wire clip on the internal flue adaptor pipe and pull

the adaptor pipe down into the flue outlet pipe, see diagram 7.5.
Pull the flue outlet pipe out of the heat exchanger.
Remove the automatic air vent pipe from the top right hand side

of the heat exchanger.
Pull the black condense pipe and vent pipe out of the top of the

condense trap body.
Unscrew the heat exchanger condense pipe from the base of

the heat exchanger.
Undo the heat exchanger flow pipe connection from the bottom

left hand side of the boiler.
Undo and remove the return pipe locking plate from the rear

panel below the heat exchanger and pull the return pipe down
and out of the casting.

Prise open the heat exchanger retaining clips on the back panel
of the appliance and remove the heat exchanger.

After refitting the heat exchanger , fill, vent and pressurise the
boiler and check for leaks.

14.22 Air Pressure switch

Remove the sensing tube from the air pressure switch.
Disconnect the wires. Unclip the air pressure switch from its
plastic retaining clip. Fit the new air pressure switch with the
sensing pipe connections downwards, see diagram 14.8.

14.23 Condense trap and siphon

Unscrew the drain cap on the trap and drain off the condensate.
Disconnect the overflow pipework from the outlet of the siphon.
From underneath the baseplate, unscrew the two condense
drain trap securing screws. Pull the condense drain trap away
from the bottom of the appliance and disconnect the heat
exchanger condense pipe, see diagram 9.1.

Check the condense drain trap gasket and if necessary replace
prior to refitting the assembly.

Insert the heat exchanger condense pipe into the trap and
siphon assembly prior to fixing to the boiler base.

Refill the condense trap as recommended in section 9.4.

14.24 Display PCB

Unscrew the two securing screws, one on the top front edge of
the base panel and the second on the bottom edge of the base
panel. Carefully remove the ribbon wire plug from the display
PCB. Unclip the PCB from its four retaining pillars on the PCB
cover.

When refitting the PCB and cover to the appliance base panel
be careful not to trap the ribbon wire behind the cover. The
ribbon wire should exit from the right hand side of the cover.

14 Replacement of Parts

Diagram 14.7

6537

Diagram 14.5

6540

PRESSURE
GAUGE

Diagram 14.6

6564

LOW WATER
PRESSURE
SWITCH

THERMOSTATIC
MIXER VALVE

RETAINING
LUGS

LOCATION
PIN

SLOT

ELECTRICAL
CONNECTION

(2 OFF)

BULK HEAD CONNECTORS

5mm
ADJUSTING
SCREW

HOT WATER
CONNECTION

COLD WATER
CONNECTION

36

221564F

14 Replacement of Parts

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

Diagram 14.8

6565

AIR PRESSURE
SWITCH

SENSING
TUBE

ELECTRICAL
CONNECTIONS

CLIPS

Key No. Part No. Description GC Part No.

1 801056 Gas control valve (80) E24293

1a 801145 Gas control valve (100) E24434

2 801064 Automatic control module (80) E24300

2a 801147 Automatic control module (100) E24436

3 801029 Ignition lead (80) E24243

3a 801140 Ignition lead (100) E24418

4 801112 Electrode E24371
5 801049 Pump E24288
6 801052 Three way valve head E24291
7 432875 Mini expansion vessel 360113
8 801034 Heating flow thermistor /Heating return thermister E24250

9 208214 Water inlet filter 281359
10 801120 Domestic hot water thermistor E24381
11 801074 Air pressure switch E24309
12 801039 Burner (80) E24257

12a 801142 Burner (100) E24426

13 801087 Injector (80) E24336

13a 801154 Injector (100) E24449

14 801040 Fan (80) E24259

14a 801040 Fan (100) E24259

6557

1

2

3

4

5

6

7

8

9

10

11

12

13

14

14.25 Control Door

Open the control door and pull the brass lugs out of their
locations in the fascia, see diagram 11.3.

14.26 Mini Expansion Vessel

If the mini expansion vessel option is fitted it can be replaced by
the following method.

Refer to section 12.10 and drain the boiler hot water circuit.
Remove the right hand casing panel as described in section

12.8.
Remove the mini expansion vessel.
Fit new vessel using a suitable thread sealant, see diagram 6.3.

14.27 Spare Part LIst