Glowworm Economy Plus 30 B Operating manual

Supplied By www.heating spares.co Tel. [phone]
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]
221481C.12.99
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.
Attached to the center of these instructions is 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
Balanced Flue Boiler
This is a Cat I2H Appliance
BS 6332
BS 5258
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.
Tobeleftwiththeuser
❏
✔
❏
✔
❏
✔
Instructions for Use
Installation and Servicing
G.C. No. 41 319 01
REGISTER YOUR GLOW-WORM APPLIANCE
FOR 1ST YEAR GUARANTEE PROTECTION
CALL 0181 380 2555
30 B
2405
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.

Supplied By www.heating spares.co Tel. [phone]
2
221481C
Important Information
CONTENTS DESCRIPTION SECTION PAGE No.
INSTRUCTIONS
FOR USE
INSTALLATION
INSTRUCTIONS
SERVICING
INSTRUCTIONS
Introduction 3
Lighting the Boiler 4
General Data 1 5
Flue & Ventilation 2 7
Water Systems 3 8
Flue and Appliance Preparation 4 10
Boiler Installation 5 12
Gas and Water Connection 6 13
Electrical Wiring 7 13
Commissioning 8 14
Instructions to User 9 16
Servicing and Replacement Parts 10 16
Fault Finding 11 19
Spare Parts 12 24
Testing and Certification
Thisboileristestedandcertificatedforsafetyandperformance. Itisthereforeimportantthatnoalterationismadetotheboiler,without
permission, in writing, from Hepworth Heating Ltd.
Any alteration not approved by Hepworth Heating Ltd., could invalidate the certification, boiler warranty and may also infringe the
current issue of the Statutory Requirements, see Section 1.3.
CE Mark
This boiler meets the requirements of Statutory Instrument No. 3083 The boiler (Efficiency) Regulations, and therefore is deemed
tomeettherequirementsofDirective92/42/EEContheefficiencyrequirementsfornewhotwaterboilersfiredwithliquidorgaseous
fuels.
Type test for purposes of Regulation 5 certified by: Notified body 0086.
Product/productioncertifiedby: Notified body 0086.
The CE mark on this appliance shows compliance with:
1. Directive 90/396/EEC on the approximation of the laws of the Member States relating to appliances burning gaseous fuels.
2. Directive 73/23/EEC on the harmonization of the Laws of the Member States relating to the electrical equipment designed
for use within certain voltage limits.
3. Directive 89/336/EEC on the approximation of the Laws of the Member States relating to electromagnetic compatibility.
INFORMATION FOR THE INSTALLER AND SERVICE ENGINEER.
Under Section 6 of The Health and Safety at Work Act 1974, we are required to provide information on substances hazardous to
health.
Insulation and Seals
Ceramicfibreandglassfibreareusedininsulationpanels,ropeandgaskets.Thecancauseirritationtoskin,eyesandtherespiratory
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.
Normalhandlingshould not cause discomfort, but follownormalgood hygiene and wash your handsbeforeeating, drinking or going
to the lavatory.If you do suffer irritation to the eyes or severe irritation to the skin seek medical attention.
Thermostat
This contains a very small amount of xylene in the sealed phial and capillary. If broken, under normal circumstances the fluiddoes
not cause a problem, but in cases of skin contact, wash with cold water.
If swallowed drink plenty of water and seek medical attention.

Supplied By www.heating spares.co Tel. [phone]
3221481C
Instructions for Use
General Notes and information
Pleasereadtheseinstructionsandfollowthemcarefullyforthe
safe and economical use of your boiler
IMPORTANT NOTICE
This boiler is for use only on G20 gas.
The Gas Safety (Installation and Use)
Regulations
InyourowninterestsandthatofsafetyitistheLawthatALLgas
appliances are installed by a competent person in accordance
with the above regulations.
Gas Leak or Fault
If a gas leak or fault exists or is suspected the boiler must be
turned off.
Advice/helpshouldbeobtainedfromyourinstallationorservicing
company or the local gas undertaking.
Protection Against Freezing
Iftheboiler is to be outof use for any long periodof time during
severeweatherconditionswerecommendthatthewholeofthe
system, including the boiler be drained off to avoid the risk of
freezingup. Ifanimmersionheaterisfittedto the domestic hot
water cylinder make sure it is switched off.
If in doubt contact you installation or servicing company,
especially if you have a sealed water system.
Maintenance
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
theparticularinstallationandusage,but ingeneralonceayear
should be enough.
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.
ItistheLawthatservicingiscarriedoutbyacompetentperson.
To obtain service, please call your installer or Heatcall (Glow-
worm’sownserviceorganisation)usingthe telephone number
on the case tray.
Please be advised that the ‘Benchmark’ logbook should be
completed by the installation engineer on completion of
commissioning and servicing.
All CORGI Registered Installers carry a CORGI ID card, and
have a registration number. Both should be recorded in your
boiler Logbook. You can check your installer is CORGI
registered by calling CORGI direct on :- 01256 372300.
Cleaning
WARNING. Thisappliancecontainsmetalparts(components)
and care should be taken when handling and cleaning, with
particular regard to edges.
Clean the casing by wiping it over occasionally with a damp
cloth or dry polishing cloth.
Do not use abrasive cleaners.
CLEARANCES Diagram 1
Balanced
Flue
Model
BALANCED FLUE BOILERS
Minimum Clearances from Walls,
Ceiling, Floor, Cupboards, etc.
AL.H. and R.H. side of casing
BTop of casing
CBottom of casing
DFront of boiler
(from a permanent surface)
5
75
150
305
A
B
C
MINIMUM
CLEARANCES
A
2399
Boiler Spaces
The boiler must be positioned so that at least the minimum
operationalandservicingspacesareprovided, seediagram 1.
If fixtures are placed close to the boiler they should be made
removable for access.
Sufficient space must be left in front of the boiler for servicing.
Boiler in a Compartment
If the boiler is fitted in a compartment or a cupboard purpose
builtventilationmustbeprovidedandkeptclear. Donotusethe
enclosed space for storage.
Overheat Safety Device
Theboilerisfittedwithasafetycutoffdevicetopreventdamage
through overheating. Should the burner or pilot go out for no
apparentreason,allowthesystemtocooldown,thenrelightthe
boiler.
Shouldthe problem persist, turn the boiler off and contact your
installation or servicing company.

Supplied By www.heating spares.co Tel. [phone]
4
221481C
2391
CONTROL
COVER 'D'
CONTROLS ACCESS Diagram 2
BOILER
CONTROLS
A
G
CB
A. BOILER THERMOSTAT KNOB
B. GAS CONTROL KNOB
C. IGNITER BUTTON
G. VIEWING WINDOW
Diagram 3
2431
MODEL AND
SERIAL NUMBER LABEL
Electrical Supply
WARNING. The boiler must be earthed.
Connection of the boiler and any system controls to the mains
supply should be by one unswitched shuttered socket a 3A
plug, both to the current issue of BS1363.
Alternatively, a 3A fused double pole isolating switch may be
used, having a minimum double pole contact separation of
3mminbothpoles,servingonlytheboilerandsystemcontrols.
The colours of three core cable are:
Brown - live, Blue - neutral, green and yellow - earth.
As the markings on your plug may not correspond with these
colours, continue as follows:
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”, “Green” or the earth symbol .
Lighting the Boiler
CAUTION. If the pilot flame goes out, either intentionally or by
accident, no attempt should be made to relight it for at least 3
minutes.
Slide the controls cover off and clear, see diagram 3.
Makesurethattheelectricalsupplytotheboilerisswitchedoff.
Identify the controls by reference to diagram 2.
Turn thermostat knob “A” fully anti-clockwise to the OFF
position.
Push and keep in gas control knob “B”.
Push and release igniter button “C” until the pilot burner lights,
lookthrough window “G”. When the pilot is alight keep the gas
control knob “B” pushed in for about 15 seconds.
Ifthepilotdoesnotlightorfails to stay alight, wait for3minutes
then repeat the lighting operation only this time keep the gas
control knob “B” pushed in for a little longer.
Instructions for Use
When the pilot is alight and stable, switch on the electrical
supply to the boiler.
Check that all external controls are calling for heat.
Turn the thermostat control knob “A” fully clockwise to “5” and
the burner will light fully in about 3 to 5 seconds, look through
window “G”.
Adjust thermostat knob to desired setting between “5” and “1”.
“5” is about 82oC (180oF).
Replace controls cover.
To Turn the Boiler Off
Forshortperiods,turnthermostatcontrolknob“A”anti-clockwise
until“O”isagainstthe setting point. The pilotwill remainalight,
to relight the main burner turn thermostat control knob “A”
clockwise to the desired setting between “1” and “5”.
For longer periods, turn the thermostat control knob “A” anti-
clockwiseuntil“O”isagainstthesettingpoint. Slidethecontrol
button“B”to theleft,thecontrolwillautomaticallyreset. Switch
off the electrical supply to the boiler.
To relight, follow the full lighting procedure given above.

Supplied By www.heating spares.co Tel. [phone]
5221481C
1 General Data
Important Notices
This boiler is for use only on G20 gas.
This boiler is suitable for fully pumped systems only.
Wherever possible, all materials, appliances and components
to be used shall comply with the requirements of applicable
British Standards.
Where no British Standard exists, materials and equipment
should be fit for their purpose and of suitable quality and
workmanship.
Sheet Metal Parts
WARNING. When installing or servicing the boiler care should
betakenwhenhandlingsheetmetalparts,toavoidanypossibility
of personal injury.
1.1 Statutory Requirements
Theinstallationoftheboilermust becarriedoutbyacompetent
person in accordance with the relevant requirements of the
current issue of:-
TheGasSafety(InstallationandUse)Regulations,TheBuilding
Regulations, The Building Standards (Scotland) Regulations
(applicable in Scotland), Local Water Company Bye-laws, The
HealthandSafetyatWorkAct,ControlofSubstancesHazardous
toHealth,TheElectricityatWorkRegulationsandanyapplicable
local regulations.
Detailedrecommendationsarecontainedinthecurrentissueof
the following British Standards and Codes of Practice:-
BS6798, BS5440 Part 1 and 2, BS5546 Part 1, BS5449,
BS6891, BS7074 Part 1 and 2, BS7593, BS7478, BS7671.
Manufacturer’snotesmustnotbetakeninanywayasoverriding
statutory obligations.
Diagram 1.1
Model A B C D E F G H J K L M N P R
30 278 20 40 600 110 490 11 170 225 300 43 133 320 414 98
GENERAL ARRANGEMENT
0.45litre
(0.10gal)
WATER
CONTENT
22.6kg
(49.8lb)
TOTAL
WEIGHT
Rc 1/2(
1/2in. BSPT)
GAS
CONNECTION
WATER
CONNECTION
45W, internal fuse F1A
ELECTRICITY
RATING
240V~50Hz Fused 3A
DATA LABEL Bottom of inner case door
2411
ELECTRICITY
SUPPLY
TABLE 1. ECONOMY PLUS DATA
HG
AB
CE
K
JLM
N
P
R
WATER
CONNECTIONS
RETURN FLOW
WATER
CONNECTIONS
GAS
CONNECTION GAS
CONNECTION
FLUE
C
L
D
F
22mm copper,
flow at right, return at left
INJECTOR 2.8 - Cat 30 - 850
The Seasonal Efficiency Domestic Boilers UK (SEDBUK) is
71.3%.
ThevalueisusedintheUKGovernment’sStandardAssessment
Procedure (SAP) for energy rating of dwellings. The test data
from which it has been calculated have been certified by B.S.I.

Supplied By www.heating spares.co Tel. [phone]
6
221481C
1 General Data
1.2 Range Rating
The boiler is range rated and may be adjusted to suit individual
system requirements.
The respective Table 2 gives the ratings and settings.
1.3 B.S.I. Certification
Theboileriscertificatedtothe current issue of British Standard
6332 Part 1, invoking the current issue of BS5258 Part 1 for
performance and safety. It is, therefore, important that no
alteration is made to the boiler without permission, in writing,
from Hepworth Heating Ltd.
Any alteration that is not approved by Hepworth Heating Ltd.,
could invalidate the B.S.I. Certification, the warranty and could
also infringe the current issue of the Statutory Requirements.
1.4 Gas Supply
The gas installation shall be in accordance with the current
issue of BS6891.
The supply from the governed meter must be of adequate size
toprovideasteadyinletworkingpressureof20mbar(8inwg)at
the boiler.
Oncompletiontestthegasinstallationforsoundnessusingthe
pressuredropmethodandasuitableleakdetectionfluid,purge
in accordance with the above standard.
1.5 Electrical Supply
WARNING. This boiler must be earthed.
All system components shall be of an approved type and shall
be connected in accordance with the current issue of BS7671
and any applicable local regulations.
Connection of the boiler and system controls to the mains
supply must be through a common isolator and must be fused
3A,maximum. Thismethodofconnectionshouldbe,preferably,
anunswitchedshutteredsocketoutletand3pinplugbothtothe
current issue of BS1363.
Alternatively, a double pole isolating switch may be used,
provided it has a minimum contact separation of 3mm in both
poles. The isolator should be clearly marked, showing its
purpose. See also Section 1.11.
Wiring to the boiler must be insulated PVC flexible type to the
current issue of BS6500 Table 16 not less than 0.75mm2(24/
0.20mm).
1.6 Contents of Packaging
The boiler is delivered in one pack.
The other pack contains the balanced flue terminal assembly
and accessories.
Refer to Section 2 to check that the flue terminal assembly
supplied is suitable.
kW
Btu/h
kW
Btu/h
m bar
in. w.g.
-7.33 10.99
-25,000 37,500
7.335.86 8.79
25,00020,000 30,000
7.24.7 10.5
2.91.9 4.2
Max.Min. Med.
TABLE 2.
1.7 Water System
Theboilermaybefittedtoanopenventedorsealedsystem,see
Section 3 for further details.
1.8 Draining Tap
A draining tap must be provided at the lowest points of the
system which will allow the entire system, boiler and hot water
cylinder to be drained off.
The boiler is provided with a drain tap for heat exchanger
draining.
Draining taps shall be to the current issue of BS2879.
1.9 Safety Valve
A safety valve need not be fitted to an open vented system.
1.10 Location
This boiler is not suitable for outdoor location.
The boiler may be installed in any room, although particular
attention is drawn to the requirements of the current issue of
BS7671 with respect to the installation of a boiler in a room
containing a bath or shower. Any electrical switch utilising
mainselectricityshouldbesosituatedthatitcannotbetouched
byapersonusingthe bath orshower. Theelectricalprovisions
oftheBuildingStandards(Scotland)Regulationsareapplicable
to such installations in Scotland.
The boiler must be mounted on a flat wall which is sufficiently
robust to take its weight.
1.11 Boiler Location
Refer to diagram 1, Instructions for Use.
The boiler must be positioned so that at least the minimum
operational and servicing clearances are provided.
Additional clearances may be required for installation.
Iffixtures are positioned next to the boiler they should be made
removable for access to pipework.
1.12 Heating System Controls
The heating system should have installed: a programmer and
room thermostat controlling the boiler.
Thermostatic radiator valves may be installed in addition to the
room thermostat.
Note: For further information, see The Building Regulations
1991-Conservationoffuelandpower,1995edition-Appendix
G, table 4b.
NOMINAL
HEAT INPUT
(GROSS)
NOMINAL
HEAT
OUTPUT
BURNER
SETTING
PRESSURE
RANGE RATING

Supplied By www.heating spares.co Tel. [phone]
7221481C
2 Flue and Ventilation
2.1 Terminal Position
The minimum acceptable spacings from the terminal to
obstructionsand ventilation openings are as shown in diagram
2.1.
Where the terminal is fitted within 850mm (34in) below plastic
guttering or within 450mm (18in) of painted eaves or painted
gutters an aluminium shield 750mm (2ft6in) long should be
fitted to the underside and immediately beneath the guttering/
eaves.
2.2 Terminal Protection
A terminal guard is required if persons could come into contact
with the terminal or the terminal could be subject to damage.
Ifaguardisrequired,itmustbepositionedtoprovideaminimum
of50mmclearance from any part of theterminaland be central
over the terminal.
A suitable guard can be obtained from,
The Tower Flue Components Ltd.,
Morley Road,
Tonbridge,
Kent,
TN9 1RA
reference “A” black,
2.3 Wall thickness
Check the wall thickness.
The standard flue set supplied is suitable for wall thickness
238mm to 330mm.
For other wall thicknesses, kits are available.
76 to 238mm - Kit 443235
324 to 580mm - Kit 443236
2.4 Boilers in a Compartment
Wheretheinstallationoftheboilerwillbeinanunusuallocation,
specialproceduresarenecessary,thecurrentissueofBS6798
gives detailed guidance.
A compartment used to enclose the boiler must be designed
and constructed specifically for this purpose. An existing
cupboard or compartment modified for the purpose may be
used. Detailsofessentialfeaturesofcupboardorcompartment
design are given in the current issue of BS6798.
Thedoorwayopeningmustbeofsufficientsizetoallowforeasy
removal of the boiler.
Where the boiler is fitted in a cupboard or compartment,
permanenthighandlowlevelventilationmustbeprovided. The
minimum ventilation areas required are given in the respective
Table 5.
2.5 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
documentIGE/UP/7/1998. Ifindoubtseekadvicefromthelocal
gas undertaking or Hepworth Heating Ltd.
Under Car Port etc.
H,I
JD
F
K
A
A
FGEA
GG
B,C B,C
FF
K
K
K
C
LL
G
G
ADIRECTLY BELOW AN OPENABLE mm
WINDOW, AIR VENT, OR ANY OTHER
VENTILATION OPENING 300
BBELOW GUTTER, DRAIN/SOIL PIPE 300
CBELOW EAVES 300
DBELOW A BALCONY OR CAR PORT 600
EFROM VERTICAL DRAIN PIPES AND
SOIL PIPES 75
FFROM INTERNAL OR EXTERNAL CORNERS 600
GABOVE ADJACENT GROUND OR
BALCONY LEVEL 300
HFROM A SURFACE FACING THE TERMINAL 600
IFACING TERMINALS 600
JFROM OPENING (DOOR/WINDOW) IN CAR
PORT INTO DWELLING 1200
KVERTICAL FROM A TERMINAL 1500
LHORIZONTALLY FROM A TERMINAL 300
MINIMUM
SPACING
Diagram 2.1
MINIMUM SITING DIMENSIONS FOR
BALANCED FLUE TERMINALs POSITION
1112
cm2
TABLE 5. COMPARTMENT AIR VENTS
HIGH LEVEL
VENT AREA LOW LEVEL
VENT AREA
in2cm2in2
100 16 100 16
50 850 8
VENTILATION
FROM
OUTSIDE
VENTILATION
FROM ROOF
OR SPACE
VENTILATION
REQUIREMENTS

Supplied By www.heating spares.co Tel. [phone]
8
221481C
3 Water Systems
Notes:
PUMP
The pump should be fitted in the flow pipework from the boiler,
with valves each side, integral if possible, it should produce a
temperature difference across the boiler of 11oC (20oF).
Flow rates should be,
11.5 Litre/min (2.5gal/min)
See diagram 3.1 for pressure loss across the boiler.
High resistance microbore systems may require a higher duty
pump.
BYPASS
The flow through the boiler must not be allowed to fall below,
7.8 Litre/min (1.7gal/min) whilst the burner is alight.
A bypass must be fitted.
3.1 Open Vented Systems
Water system
Foranopenventedsystem the boilermustbesuppliedfroman
unrestricted water supply taken from a feed and expansion
tank, situated at a maximum height of 27.5metres (90ft) above
the boiler.
The cold feed supply must be 15mm minimum size.
It is important that the relative positions of the pump, cold feed
and open vent are as shown in diagram 3.2.
3.2 Cylinder
SINGLE FEED SELF PRIMING CYLINDERS ARE NOT
RECOMMENDED.
Thehotwatercylindermust be adoublefeedfullyindirecttype.
3.3 Inhibitor
Attention is drawn to the current issue of BS5449 and BS7593
on the use of inhibitors in central heating systems.
If an inhibitor is to be used, contact a manufacturer for their
recommendations for the best product to use.
Whenfittingtheboilerintoan existing system take special care
todraintheentiresystemincludingtheradiators,thenthoroughly
cleaning out before fitting the boiler whether or not adding an
inhibitor.
Sealed Water Systems
Theinstallationshouldcomplywiththeappropriaterequirements
of the current issue of BS4814, BS5449 BS6759 BS6798 and
BS7074 Part 1 and 2.
See diagram 3.3 for a suggested layout.
3.4 Safety Valve
A safety valve must be fitted to a sealed water system.
It shall be preset, nonadjustable with a lift pressure of 3bar,
incorporating seating of a resilient material, a test device and a
connection for drain.
The drain from the safety valve must be routed clear of any
electrical fittings and positioned so that any discharge can be
seen.
PRESSURE LOSS OF BOILER
ECONOMY Diagram 3.1
2761
LITRES / MINUTE
GALLONS / MINUTE
(m head of water)
WATER PRESSURE LOSS
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0510 150
5
10
15
20
25
123
(m head of water)
WATER PRESSURE LOSS
Diagram 3.2
Open (vented) system.
Recommended
relationship between
pump, cold feed and
vent.
22 mm (MIN) VENT
FEED AND
EXPANSION
CISTERN
15mm (MINIMUM)
COLD FEED
15mm (MINIMUM)
BY-PASS WITH
LOCKSHIELD VALVE
450mm
MIN.
HEIGHT
1150mm
MIN.
150
mm
MIN.
BOILER
PUMP
150mm
MAX
FLOW
RET.
ALTERNATIVE
PREFERRED
RET.
CYLINDER
FLOW
HEATING
0392

Supplied By www.heating spares.co Tel. [phone]
9221481C
3 Water Systems
3.5 Expansion Vessel
A diaphragm type expansion vessel, conforming to the current
issue of BS4814 (see also the current issue of BS7074 Part 1
and2)must beconnectedata pointclosetothe inletsideofthe
circulatingpump, see diagram 3.3, unless laid down differently
by the manufacturer.
The expansion vessel volume depends on the total water
systemvolumeandtheinitialsystemdesignpressure. For any
systemanaccuratecalculationof the vesselsizeisgiveninthe
current issue of BS7074 Part 1.
Example, for an initial system design pressure of 0.7bar, the
minimum total vessel volume required is 0.063xTotal System
volume.
Note, a higher initial design pressure requires a larger volume
expansion vessel.
Guidance on vessel sizing is also given in the current issue of
BS5449 and BS7074 Part 1.
Thechargepressuremustnotbelessthanthestaticheadofthe
system, that is, the height of the highest point of the system
above the expansion vessel.
The water content of the boiler is given in the Data Table 1.
3.6 Pressure Gauge
A pressure gauge with set pointer and covering at least the
range 0 to 4bar (0 to 60lb/in2) shall be permanently fitted to the
systeminaposition whereitcanbeseenwhen carryingoutthe
filling operation.
SEALED WATER SYSTEM
DIAGRAMATIC LAYOUT Diagram 3.3
5812
3 LITRES (0.66 gals)
MAKE-UP BOTTLE
(if required)
NON-RETURN
VALVE
AUTO
AIR
VENT
FLOW
DRAIN
COCK BOILER
SAFETY
VALVE
(Make-up
alternatives) EXPANSION
VESSEL
PRESSURE
GAUGE
CIRCULATING
PUMP
FILLING POINT
AIR
RELEASE
POINT
HEATING CIRCUIT
15mm (min)
BY-PASS WITH
LOCKSHIELD
VALVE
RETURN

Supplied By www.heating spares.co Tel. [phone]
10
221481C
2763
TOP FIXING HOLES 228
BOTTOM
FIXING
HOLE
281
186
332 220
46
PREPARED
HOLE IN
WALL
BOILER
Diagram 4.1
BOILER FIXING DIMENSIONS
C
L
3 Water Systems
3.7 Cylinder
SINGLEFEEDINDIRECTCYLINDERSARENOTSUITABLE.
The hot water cylinder must be of the indirect coil type. It must
be suitable for working at a gauge pressure of 0.35bar above
the safety valve setting.
3.8 Water Make Up
Provision must be made for replacing water lost from the
system. A make up vessel mounted above the highest point of
the system and connected through a non-return valve to the
system on the return side of either the hot water cylinder or
system.
Alternatively, provision for make up can be made by using a
filling loop.
3.9 Filling Sealed Water Systems
Provision for filling the system at a low level must be made.
Three methodsof filling are shown in diagram 3.4. Theremust
be no permanent connection to the mains water supply, even
through a non-return valve.
METHOD 1
METHOD 2
METHOD 3
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
HEATING
SYSTEM
SERVICING
VALVE
SUPPLY
STOP VALVE
SUPPLY
PIPE
HOSE
UNIONS DOUBLE CHECK
VALVE ASSEMBLY
OVERFLOW
CISTERN
COMBINED
CHECK VALVE
AND VACUUM
BREAKER
PRESSURE
REDUCING
VALVE
FILLING SEALED
WATER SYSTEMS Diagram 3.4
3132
4 Flue and Appliance Preparation
4.1 Positioning
Place the template, provided, on the wall in the required position
and mark location of the balanced flue hole, see diagram 2.1.
Cut the hole in the wall to accept the wall liner, see diagram 4.1.
Make good any plasterwork at this stage. When dry, select the
liner “G”, see diagram 4.2. Push into the hole until the flange is
flush with the internal wall. Fit the liner “B” from inside so that it is
flush with the outside brickwork. Mark the two liner positions and
remove. Alignthemarksonthelinersandtapethemtogetherwith
the tape provided.
Thewallliner“B”isnotrequiredforwallthicknesslessthanlength
ofduct“G”ontheshortflueset. Forlesserwallthicknessthanduct
“G” cut the plain end to the required length.
Reposition the template on the wall in line with the wall opening,
or see diagram 4.1.
Mark positions for the three fixing screws.
Drill and plug the fixing holes, suitable for No.10x50mm wood
screws and plugs.

Supplied By www.heating spares.co Tel. [phone]
11 221481C
4 Flue and Appliance Preparation
STANDARD and SHORT FLUE Diagram 4.2
ATERMINAL ASSEMBLY
BWALL LINER EXTENSION
CCASE SEAL
DFIXING STRAPS
EFLUE HOOD
FOUTLET DUCT
GWALL LINER SLEEVE
HBOILER UNIT
JLUG
KHOLE FOR CORD/STRING
LBOTTOM LOCATION
AD
B
K
J
E
F
L
GCH
FLUE DUCT
securing screw
Diagram 4.3INNER AND OUTER CASING
2407
LUG
OUTER
CASE
INNER
CASE
OUTER
CASE
LUG
INNER CASE
SECURING
SCREWS (TOP)
OUTER CASE
SECURING
SCREW
INNER
CASE
INNER CASE
SECURING
SCREWS
(BOTTOM)
4.2 Appliance Preparation
Remove the controls cover by pulling it forwards and off.
Removetheoutercasebyundoingthescrewatthebottomand
unhooking at the top.
Remove the inner case by undoing the screws at the top and
bottom, see diagram 4.3.
Remove the flue hood by releasing the wing nuts and remove
angle,seediagram 4.4. Liftofffluehood. Removethe two flue
duct screws.
Fit sponge seal “C” around the spigot at the back of the boiler,
adhesive face to the back of the case “H”, see diagram 4.2.
Takethesidestripsfrompackagingandhookthemoverthetop
edge of the side panel and secure with a screw at the bottom.
Diagram 4.4
2769
WING NUT
FLUE
HOOD
HOOK
BOLT
TERMINAL
STRAP LUG
SECURING
ANGLE

Supplied By www.heating spares.co Tel. [phone]
12
221481C
Diagram 5.1
LONG FLUE
K
J
F
E
FLUE DUCT
SECURING
SCREW
ALDB
GC
H
A TERMINAL ASSEMBLY
B LONG WALL LINER EXTENSION
C CASE SEAL
D LONG FIXING STRAP
E FLUE HOOD
F FLUE DUCT
G LONG WALL LINER SLEEVE
H BOILER UNIT
J LONG FLUE DUCT SLEEVE
K LONG FLUE DUCT EXTENSION
L BOTTOM LOCATION ANGLE
5 Boiler Installation
5.1 External Access Procedure
Fit the slotted straps “D” to the terminal “A” by placing over the
lugs and then bending the lugs to secure, see diagram 4.2.
From the inside fit the wall liner assembly “B” and “G” into the
hole.
Fit the top two fixing screws, allow them to stand proud to
accept the keyhole fixing slots on the boiler.
Mount the boiler and tighten the top screws and fit bottom
screw.
Locate and support the terminal, note, TOP is marked, see
diagram 4.2.
Analternative method of support is to attach a length of cord or
string,totheterminalthroughthesmallholeinthetopcentre of
thebaffle,seediagram4.2. Attachasuitableweighttothefree
end of the cord etc. Pass the weight and cord through the hole
in the wall.
Working from the inside, attach the straps to the lugs on the
boiler, see diagram 4.4, bend the lugs and cut off excess strap
length.
Push the flue duct “F” into the terminal with the unflanged end
against the terminal. Ensure that the lower flange duct “F” fits
behindthecombustionchamberrearpanel. For wallslessthan
230mm thick cut to required length at the plain end of the duct.
Refit the two screws through the duct flange, but do not over
tighten.
Replace flue hood, securing angle, tie rods and wing nuts.
Refit the inner cover and secure with the screws previously
removed.
5.2 Internal Access Procedure
Ifrequiredtheterminalcanbeinstalledfrominsidethepremises.
Fit the slotted straps “D” to the terminal “A” by placing over the
lugs and then bending the lugs to secure, see diagram 4.2.
Fitthetoptwofixingscrews,allowthemtostandproudtoaccept
the keyhole fixing slots on the boiler.
Attach a length of cord to the terminal through the small hole
provided in the top centre of the baffle.
Fitthelinerassembly“B”and“G” into the holethroughthewall.
Pass the terminal through the wall liner assembly, using the
cord with a suitable weight attached to hold the terminal in
position. NOTE,theterminalTOPisindicatedandtheflangeon
the wall plate is located inside the wall liner assembly.
Hook the appliance onto the screws passing the string and
weight through the air duct in the back of the appliance.
Tighten the two upper screws and fit the bottom screw.
Attachthetwoslottedstrapsfromtheterminaltothetwolugson
theappliance,seediagram,bendlugstosecure. Cutoffexcess
strap length and remove cord.
Push the flue duct “F” into the terminal with the unflanged end
against the terminal. Ensure that the lower flange duct “F” fits
behindthecombustionchamberrearpanel. For wallslessthan
230mm thick cut to required length at the plain end of the duct.
Refit the two screws through the duct flange, but do not over
tighten.
Replace the flue hood, securing angle, tie rods and wing nuts.
Refit the inner cover and secure with the screws previously
removed.

Supplied By www.heating spares.co Tel. [phone]
13 221481C
5 Boiler Installation
5.3 Installing the Long Flue Set
Refer to diagram 5.1.
Theflueduct“F”,flueductextension“K”andflueductsleeve“J”
need to be assembled together to suit wall thickness.
This assembly is 75mm longer than the wall liner assembly “B”
and “G” already prepared, with a minimum overlap of 40mm at
each joint. Use the tape provided to make a permanent
assembly of these parts.
Pushtheflueductassemblyintotheterminal,withtheunflanged
endenteringthe terminal. Ensurethatthelowerflangeduct“F”
fits behind the rear panel of the combustion chamber.
Refit the two screws through the duct flange, but do not over
tighten.
Replace the flue hood, securing angle, tie rods and wing nuts,
do not over tighten.
Refit the inner cover and secure it with the screws previously
removed.
Connect the gas supply to the Rc1/2gas cock.
Thewholeofthegasinstallation,includingthemeter,shouldbe
inspected, tested for soundness and purge in accordance with
the current issue of BS6891.
Connect the water to the boiler using the nuts and olives
supplied, to BS2871 copper tube.
7 Electrical Wiring
6 Gas and Water Connection
CONTROL BOX Diagram 7.1
STRAIN
RELIEF
GROMMET
EARTH
POST
RETAINING
STRAP
SECURING
SCREWS
TERMINAL
STRIP
2420
FASTENER
Warning. The boiler must be earthed and have a permanent
mains supply.
7.1 Electrical Connection
To remove the control box release the two screws at the front,
see diagram 7.1 and lower the box until it is clear then push it
backward to disengage the hinge at the rear, see diagram 7.1.
Take care not to damage the thermostat and capillaries.
Thread the mains lead through the clamp in the rear of the
control box cover and connect to the terminal strip.
When making connections, ensure that the earth conductor is
made longer than the others so that it is the last to become
disconnected.
7.2 Pump and External Controls Connections
Thepumpmustbewiredintotheboilercontrolboxasshown in
diagram 7.2.
Anyexternalcontrolsmustonlybewiredtointerrupttheredlink
between terminals 9 and SL.
Take the strain relief grommets from the loose items pack.
Placearoundtheexternalcontrolsandpumpconnectioncables
respectively squeeze the sides of the grommets when pushing
them into the obround holes in the rear of the control box, see
diagram 7.1.
Makesurethesupplycableandallexternalcablesaresecured.
7.3 Testing
In the event of an electrical fault after installation preliminary
system checks must be carried out, that is, earth continuity,
polarity and resistance to earth, using a suitable multimeter.

Supplied By www.heating spares.co Tel. [phone]
14
221481C
Diagram 8.1BOILER COMPONENTS
A. BOILER THERMOSTAT H. GAS RATE ADJUSTMENT SCREW
B. GAS CONTROL KNOB H. (UNDER COVER SCREW)
C. IGNITION BUTTON J. GAS SERVICE COCK
G. VIEWING WINDOW K. PRESSURE TEST POINT
L. PILOT BURNER ADJUSTMENT SCREW
J (SHOWN OFF)
B
H
G
L
MODEL AND
SERIAL NUMBER
A C K
2416
7 Electrical Wiring
Diagram 7.2
WIRING DIAGRAM FOR CONTROL BOX
2419
BROWN
BLUE
GRN / YELLOW
BROWN
BLUE
240~50Hz
PERMANENT
MAINS SUPPLY
FUSED AT 3A
L
N
L
N
CIRCULATION
PUMP
CHASSIS
EARTH
POST
GRN/YEL
GAS VALVE
BROWN
BLUE
PURPLE
RED
RED
BROWN 73
98 6
COMBINED THERMOSTAT
AND PUMP OVERUN
BROWN
BLUE
GRN / YELLOW
Remove Red Link
between 9 and SL
when fitting a time
control etc.
(If link is not
removed the
circulation pump
will run constantly.)
SWITCHED
CONTROL
TIME SWITCH
PROGRAMMER ETC.
(if fitted)
NLSL 987
NL 98 7
SL
8 Commissioning

Supplied By www.heating spares.co Tel. [phone]
15 221481C
8 Commissioning
8.1 All Systems
Makesurethatthesystemhasbeenthoroughlyflushedoutwith
waterwithoutthepumpinplace. Refitthepump,fillthesystem
with water, making sure that all the air is properly vented from
the system and pump.
Before operating the boiler check that all external controls are
calling for heat.
8.2 Sealed Water Systems Only
Flush the whole system with cold water without the pump in
place. Refit thepumpandfilluntilthepressuregaugeregisters
1.5bar (21.5lbf/in2). Clear any air locks and check for water
soundness.
Check the operation of the safety valve, by allowing the water
pressure to rise until the valve opens. The valve should open
within +/-0.3bar (+/-4.3lbf/in2). of the preset pressure. Where
this is not possible, conduct a manual check and test.
Release cold water to initial system design pressure.
Thesetpointeronthepressuregaugeshouldbesettocoincide
with the indicating pointer.
8.3 Initial Lighting and Testing
Refit the outer case, see diagram 4.5.
Identify the controls by reference to diagram 8.1.
Turn the boiler thermostat to “O” the off position.
Removethe gas pressure test point screw “K” and fit a suitable
pressure gauge.
Turn the electrical supply on and check that the pump is
circulating water through the system.
OPEN ALL WINDOWS AND EXTINGUISH ANY NAKED
LIGHTS, PIPES, CIGARETTES etc.
Turn on the main gas supply and purge in accordance with the
current issue of BS6891.
Turn boiler gas service cock “J” to “On”.
Depress control button “B”, keep pressed in and at the same
timeoperatethepiezounitbutton“C”untilthepilotburnerlights.
After the pilot burner lights keep the button “B” depressed for
about15 seconds. If the pilot burner fails to stay alight a safety
deviceprevents immediate relighting. Do not attemptto relight
until the safety device has reset. Check the length of the pilot
flame, it should envelop the thermocouple tip as shown in
diagram 10.3. The pilot rate can be adjusted by turning screw
“L” having first removed the gas valve cover, see diagram 8.1.
Testpilotsupplyconnectionsforgassoundnesswithasuitable
leak detection fluid.
Fit the outer case, secure with the screws previously removed.
Make sure that the pilot is alight and stable, view through
windows “G”.
Set the boiler thermostat knob “A” between “1” and “5” and
checkthattheburnerlightssmoothly. Checkthegasconnections
for gas soundness with a suitable leak detection fluid.
To set the burner pressure operate the boiler for 10 minutes,
remove the gas valve cover, if not already removed, adjust the
gaspressurebyscrew“H”untiltherequiredpressureisobtained,
see relevant Table 2 for setting pressures.
Align and attach the self adhesive arrow, from the loose items
pack, in the appropriate space beneath the “MIN” and “MAX”
column on the Data label.
Should any doubt exist about the gas rate this should be
checked at the meter, using a stop watch to time at least one
cubic foot of gas consumption.
Remove the pressure gauge and refit the test point screw,
making sure that a gas tight seal is made.
Replace gas valve cover.
8.4 Testing
Check the operation of the flame failure device on the boiler by
turningthegasservicecockoff,tomakesurethatthegasvalve
shuts down within 60 seconds, indicated by a “click” from the
valve.
8.5 Flushing
Allow the system to reach maximum working temperature and
examine for water leaks.
Thesystemshouldthenbeturnedoffanddrainedrapidlywhilst
hot.
Refill the system and vent all air as before and again checking
for water leaks.
8.6 Adjustment - All Systems
Whencommissioning the system the boilershould first be fired
with the bypass fully closed on full service, that is, central
heating and domestic hot water. The system should then be
balanced,adjustingthepumpandlockshieldvalveasnecessary.
Having achievedasatisfactoryconditionoperatetheboilerwith
thebypassvalvefullyclosedonminimumload,normallythiswill
be central heating only with one radiator in the main living area
operating. The valve should be gradually opened to achieve a
flow rate of 7.8 litre/min (1.7gal/min) 30, 10.5 litre/min (2.3gal/
min)40, and 13.2 litre/min (2.9gal/min) 50.
UNDER NO CIRCUMSTANCES SHOULD THIS VALVE BE
LEFT IN THE FULLY CLOSED POSITION.
Operatetheboileragainonfullserviceandcheckthebalancing,
making further adjustments as necessary.
If thermostatic radiator valves are fitted care must be taken to
ensureanadequateflowratewhenthevalvesclose,refertothe
current issue of BS7478 for guidance.
Refit the controls cover.
8.7 Sealed Water Systems
Sealed water systems should be adjusted to the initial design
pressure and the set pointer repositioned.

Supplied By www.heating spares.co Tel. [phone]
16
221481C
Diagram 10.1
ACCESS for SERVICING
Casing not illustrated for clarity
COMBUSTION
CHAMBER
FRONT PANEL
SECURING
SCREW (4)
0947
SECURING ANGLE
HOOK
BOLT (2)
FLUE
HOOD
FRONT
PANEL
WING NUT (2)
WING NUT
9 Instruct User in Correct Operation of the Boiler
Hand the Instructions for Use to the user for their retention.
Instructanddemonstratethesafeandefficientoperationofthe
boiler, heating system and domestic hot water system.
Advise the user, that to ensure the continued efficient and safe
operation of the boiler it is recommended that it is checked and
serviced at regular intervals. The frequency of servicing will
depend upon the particular installation conditions and usage,
but in general once a year should be enough.
It is the Law that any servicing is carried out by a competent
person.
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.
Reminder, leave these instructions with the user.
Advise the user that the ‘Benchmark’ logbook should be
completed by the installation engineer on completion of
commissioning or servicing.
10 Servicing and Replacement of Parts
Servicing and replacement of parts must be carried out by a
competent person.
Beforecommencinga serviceorreplacingparts isolatethegas
and electrical supplies.
Replacement of parts is in the reverse order to removal unless
stated otherwise.
10.1 Heating Body - Service
Remove the controls cover by pulling it forward and off.
Remove the outer casing by releasing the screw at the bottom
and unhooking at the top.
Remove the inner case by releasing screws at the top and
bottom, see diagram 4.5.
Toremove the flue hood, release wing nuts and lift off securing
angle and flue hood, see diagram 10.1.
Remove the combustion chamber front panel by undoing the
wingnutatthebottomfrontandthefourscrewssecuringittothe
combustion chamber sides, see diagram 10.1.
Remove the two screws and washers securing the pilot burner
and shield to the main burner, see diagram 10.2.
Pullthepilotassemblyforwardenoughtoallowthemainburner
to be freed from the injector. Raise the burner up at the front,
withdraw forward. Take care not to damage the insulation and
the pilot burner and electrode assemblies.
Place a sheet of paper in the combustion chamber and brush
away any deposits.
Remove the paper and debris.
10.2 Main Burner - Service
Generally follow the instruction in “Heating Body - Servicing”.
With the main burner removed the injector can be unscrewed
and replaced as necessary, using a new sealing washer.
If cleaning do not use a wire or sharp instrument on the hole.
Whenreplacingthemainburnermakesurethatitispushedfully
home onto the injector and that the guides are engaged on the
injector manifold.
10.3 Pilot Burner and Injector
Generally follow the instruction in “Heating Body - Servicing”.
Withthemaincaseandcontrolscoveretc., removed as above,
pull off ignition lead from the electrode.
Unscrewthetubingnutatthebaseofthepilotburner,releasing
thepilotpipe. Removethepilotinjectorbyunscrewingfromthe
pilot burner, see diagram 10.1.
Release the wing nuts securing the flue hood, see diagram
10.1.
Remove the combustion chamber front panel as above.
Remove the two screws and washers securing the pilot burner
and pilot shield to the main burner, see diagram 10.2.
Remove the pilot shield complete with electrode.
Unscrew the thermocouple nut.
The pilot burner can be lifted away.
Take care not to damage the electrode.
When replacing make sure that the spark gap is as shown in
diagram 10.3.
10.4 Thermocouple
Generally follow the instructions in “Heating Body - Servicing”.
Release, but do not remove, the two screws securing the front
and rear gland plates. Pull the front gland plate forward, see
diagram 10.4. Disconnect the thermocouple at the gas valve
and remove.
Usetheoldthermocoupleasapatternwhenfittingthenewone.
Do not tighten the nut at the gas valve more than a quarter turn
beyond finger tight.
Check the electrode spark gap, see diagram 10.3.
10.5 Electrode
Generally follow the information under Section 10.3.
Unscrew the electrode from the pilot shield.
When refitting check that the gap is as in diagram 10.3.

Supplied By www.heating spares.co Tel. [phone]
17 221481C
10 Servicing and Replacement of Parts
Diagram 10.2
PILOT ASSEMBLY
M3
SCREW
IGNITION
LEAD
(clear end)
MICA WINDOW
PILOT
INJECTOR
PILOT
TUBING NUT
ADAPTOR
OLIVE THERMOCOUPLE
THERMOCOUPLE
NUT
PILOT
SHIELD
SECURING
SCREWS ELECTRODE
1049
10.6 Over Heat Cutoff
Generally follow the information under Section 10.3.
Remove the two screws securing the over heat cutoff to the
clamp, see diagram 10.5.
Release connections at the gas valve, see diagram 10.6.
Release but do not remove the two screws securing the front
andrearglandplates,seediagram 10.4andwithdrawthecutoff
leads.
Whenrefittingsmearalittleoftheheatsinkcompound,supplied,
between the face of the cutoff and the water pipe, ensure that
it is correctly located on the pipe.
10.7 Gas Valve
See diagram 10.6.
Gain access as under Section 10.3.
Remove screw to release gas valve cover.
Disconnect all leads and pipes at the valve.
Undo the four screws each side of the valve to release the
service cock and burner supply tube, take care not to damage
to “O” rings.
Re-assemblynote,whenrefittingthegasvalvetake care not to
damage the “O” rings.
Remake all connections.
Do not tighten the thermocouple nut more than a quarter turn
beyond finger tight.
It will be necessary to purge the pipework and valve before
relighting - refer to Commissioning.
10.8 Electrical Control Box
Remove controls cover and outer casing as Section 10.1.
Remove retaining clip from the boiler thermostat phial pocket
and withdraw the phial, see diagram 10.5.
Removethecontrolboxby undoing thetwofixingscrewsatthe
front and lower the front of the box until it is clear of the cover.
Push the box towards the rear of the boiler to disengage the
hinge and lower, see diagram 7.1. Diagram 10.3
PILOT FLAME & SPARK GAP
14 to 17 mm
14 to 17 mm
ELECTRODE THERMOCOUPLE
SPARK GAP
3 to 4 mm
1053
RELEASE SCREWS
DO NOT REMOVE
AND PULL FRONT
GLAND PLATE FORWARD
REAR
GLAND
PLATE
GLAND PLATE Diagram 10.4
IGNITION
LEAD
OVERHEAT
CUT-OFF LEADS THERMOSTAT
CAPILLARY
THERMO-
COUPLE
PILOT
TUBE
FRONT GLAND
PLATE
0394
Release, but do not remove, the two screws securing the front
and rear gland plates. Pull the gland plates forwards, see
diagram 10.4.
Withdraw the thermostat capillary through the bottom of the air
duct.
Disconnect cables (a) mains, L.N.E. (b) pump at terminal 8, 7
and earth stud, (c) cables at gas valve, (d) disconnect any
remote controls at terminal 9 and SL.
When replacing refer to diagram 7.2 for electrical connections.
Smear the thermostat phial with heat sink compound and
ensure it is secured, with the retainer, in the pocket.

Supplied By www.heating spares.co Tel. [phone]
18
221481C
GAS VALVE ASSEMBLY Diagram 10.6
EXT. SCREW (4)
'O' RING
'O' RING
EXTENSION
SCREW (4)
THERMOCOUPLE
NUT
ELECTRICAL
CONNECTOR (2)
PILOT
TUBE
NUT
GAS VALVE
CONNECTORS
GAS SERVICE
COCK
(SHOWN OFF)
2414
INTERRUPTER
10 Servicing and Replacement of Parts
10.9 Piezo Unit
Gain access as in Section 10.3.
Disconnect the ignition lead and remove backing nut from the
piezo unit.
10.10 Ignition Lead
Remove controls cover and outer casing as above.
Release, but do not remove, the two screws securing the front
and rear gland plates. Pull the gland plates forwards, see
diagram 10.4.
Remove the ignition lead, when replacing ensure that the clear
end is fitted to the electrode.
10.11 Thermostat
Gain access as Section 10.3.
Remove and support the control box as Section 10.9.
Remove the control knob and electrical connections from the
thermostat body.
Release, but do not remove, the two screws securing the front
and rear gland plates. Pull the gland plates forward, see
diagram 10.4.
Remove the two screws securing the thermostat to the control
box. The thermostat may now be removed withdrawing the
capillary through the bottom of the air duct.
When replacing smear the thermostat phial with the heat sink
compound supplied, before replacing and securing with the
retainer in the pocket.
Diagram 10.5
THERMOSTAT
PHIAL/OVERHEAT
CUT-OFF
HEAT
EXCHANGER
THERMOSTAT
PHIAL
OVERHEAT
CUT-OFF
RETAINING
CLIP
CUT-OFF
SECURING
SCREW(S)
0951

Supplied By www.heating spares.co Tel. [phone]
19 221481C
11 Fault Finding
Remedy
11.3 Thermostat Will Not Cut Out
Thermostat phial not fitted in pocket.
Faulty thermostat.
11.2 Main Burner Will Not Light
External, remote controls not “On.”
Boiler thermostat not on.
Check that any remote controls are calling for heat.
Check boiler thermostat is in an “On” position, see
also Section 11.9.
Fit phial in pocket.
Replace thermostat.
11.1 Pilot Goes Out after a Period of
Remaining Alight
Front cover not correctly fitted.
Flue parts not fitted or sealed properly.
Electrical supply failure causing over heat cutoff to
operate.
Operating cut-off operating.
Pump incorrectly wired.
Fault and Cause
11.6 Appliance Noisy in Operation*
Overgassed.
Complete lack of water.
Air in system.
Water flow rate.
Check burner pressure against data label and adjust
only if more than 10% away from stated required
figure.
Check system controls for correct installation or
correct type of controls.
Remove air from system. When system is first
commissioned the air dissolved may take some time
to boil out, therefore attempts should be made to
vent air during the first weeks of the installation.
Check venting of system, as air bubbles can remain
suspended in the water if system is not well vented.
Check that flow rate is correct. Check that pump is
correct size and is correctly adjusted. Bypass not
fitted or set correctly.
Fit parts correctly.
Seal cavity or fit flue parts correctly as described in
installation instructions.
Relight pilot.
Refer to Section11.3.
Connect pump in accordance with diagram 7.2.
11.4 Overheat Cutoff Cuts Out Prematurely
Air in heating body.
Water circulation low or stopped.
Overheat cutoff operates before boiler cycles on
maximum boiler thermostat setting.
The correctly set overheat cutoff operates
prematurely. There is no air in the heating body
and water circulation satisfactory.
Vent system. Alter system layout if necessary.
Pump not functioning correctly. Check pump is wire
directly to the boiler. Alter system if necessary.
Change faulty overheat cutoff.
Change faulty heating body.
Increase setting.
Increase gas pressure.
Check burner pressure against data label. Reset only
if more than 10% away from required figure.
* There remains on most boilers a residual noise more noticeable at high temperatures. Normal operation of
the boiler over a period should remove most noise.
11.5 Insufficient Heat
Thermostat set too low.
Inlet gas pressure inadequate.
Governor setting incorrect.
(ensure thermostat is on maximum setting).

Supplied By www.heating spares.co Tel. [phone]
20
221481C
11 Fault Finding
THERMOCOUPLE AND BOILER OVERHEAT CUTOFF FAULT FINDING Diagram 11.2
With the boiler cold, check connections of the thermocouple, boiler overheat cut-off and gas valve.
Disconnect overheat cut-off connectors at points A and B at the gas valve, see diagram.
Test continuity of the overheat cut-off. Is there continuity ?
Re-connect boiler overheat cut-off to points A and
B. Disconnect thermocouple at point D of gas
valve. Test continuity between point C and the
body of the body of the gas valve. Is there
continuity ?
YES
Faulty boiler overheat
cut-off, renew
Faulty cut-off
connectors into gas
valve, either at A or C.
Renew where faulty
Faulty thermocouple,
renew
NO
YES
Thermocouple and boiler overheat circuit Satisfactory.
YES
Test continuity of thermocouple between inner
connection point D and point E. is there
continuity ? NO
NO
THERMOCOUPLE Diagram 11.1
CONNECTION 'E'
CONNECTION 'D'
CONNECTION 'B'
GAS VALVE
BOILER
OVERHEAT
CUT-OFF
CONNECTION 'A'
2487
CONNECTION 'C'
11.7 Thermocouple and Overheat Device.
To test the thermocouple a meter with a range of 0 to 30mV is
required.
Symptoms: The pilot burner fails to stay alight.
Test the thermocouple, overheat cutoff and thermocouple
connectors as described in fault finding chart 11.2.
Check the millivoltage of the thermocouple closed circuit at
points “A” and “E”, see diagram 11.1.
This should be within the range 6 to 13mV.
Take the millivoltage drop reading and refer to thermocouple/
overheat cutoff fault finding diagram 11.2.