Glowworm Ultimate 100FF Operating 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]
221966B.04.03
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
100FF 120FF
Fanned 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.
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
4272
❏
✔
❏
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Instructions for Use
Installation and Servicing
G.C. No. 41 047 59 G.C. No. 41 319 75
REGISTER YOUR GLOW-WORM APPLIANCE
FOR 1ST YEAR GUARANTEE PROTECTION
CALL 0208 247 9857

2
221966B
Important Information
Testing and Certification
This boiler is tested and certificated for safety and performance. It is therefore important that no alteration is made to the boiler, without
permission, in writing, from Hepworth Heating Ltd.
Any alteration not approved by Hepworth Heating Ltd., could invalidate the certification, boiler warranty and may also infringe the
current issue of the Statutory Requirements, see Section 1.4.
CE Mark
This boiler meets the requirements of Statutory Instrument No. 3083 The boiler (Efficiency) Regulations, and therefore is deemed
to meet the requirements of Directive 92/42/EEC on the efficiency requirements for new hot water boilers fired with liquid or gaseous
fuels.
Type test for purposes of 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.
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. 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, GLASSYARN.
These can cause irritation to skin, eyes and the respiratory tract. If you have a history of skin complaint you may be susceptible to
irritation. High dust levels are usual only if the material is broken. Normal handling should not cause discomfort, but follow normal
good hygiene and wash your hands before eating, drinking or going to the lavatory. If you do suffer irritation of the eyes or severe
irritation to the skin seek medical attention.
THERMOSTATS
These contain very small amounts of xylene in the sealed phial and capillary. If broken, under normal circumstances the fluid does
not cause a problem, but in case of skin contact, wash with cold water. If swallowed drink plenty of water and seek medical attention
CUT-OFF DEVICES
These contain activated charcoal and a very small amount of chlorodifluormethane in the sealed phial and capillary. If broken, under
normal circumstances the fluid does not cause a problem. If there is irritation to the eyes or skin then seek medical attention.
Spare Parts
REMEMBER, When replacing a part on this appliance, use only spare parts that you can be assured conform to the safety and
performance specification that we require. Do not use reconditioned or copy parts that have not been clearly authorised by Hepworth
Heating Ltd.

3221966B
Introduction 3
Lighting the Boiler 5
General Data 1 6
Flue Terminal 2 9
Water Systems 3 10
Flue and Appliance Preparation 4 13
Boiler Installation 5 17
Flue Fixing 6 19
Electrical Connectors 7 20
Commissioning 8 21
Instructions to the User 9 24
Servicing 10 24
Fault Finding 11 27
Replacement of Parts 12 31
Spare Parts 13 34
CONTENTS DESCRIPTION SECTION PAGE No.
INSTRUCTIONS
FOR USE
INSTALLATION
INSTRUCTIONS
SERVICING
INSTRUCTIONS
Introduction
WARNING. It is important that the case (not the controls tray)
is not disturbed or removed other than for servicing by a
competent person.
Please read these instructions and follow them carefully for the
safe and economical use of your boiler.
The Ultimate FF series are fanned flue boilers designed to
provide central heating and indirect domestic hot water.
The boiler is fully automatic in operation having only one user
control, the control thermostat.
Important Notice
This boiler is for use only on natural gas (G20).
The Gas Safety (Installation and Use)
Regulations
In your interest and that of gas safety it is the law that ALL gas
appliances are installed by a competent person in accordance
with the above regulations.
Gas Leak or Fault
If a gas leak or fault exists or is suspected, the boiler must be
turned off, including the electrical supply and must not be used
until the fault has been put right.
Advice/help should be obtained from your installation/servicing
company or the local gas undertaking.
Electrical Supply Failure
Failure of the electrical supply will cause the burner to go out.
Should this occur, operation of the appliance will normally
resume after the electrical supply is restored.
If the boiler does not relight after an electrical supply failure the
overheat safety cutoff device may need resetting, remove the
controls cover and press the reset button, refer to diagram 1.
Overheat Safety Cutoff
If the overheat safety cutoff device operates on any other
occasion than an electrical supply failure, press the reset button
as in “Electrical Supply Failure”. If the overheat operates again,
turn the appliance off and contact your installation/servicing
company.
Instructions for Use
Important Information

4
221966B
Maintenance
To ensure the continued efficient and safe operation of the
boiler it is recommended that it is checked and serviced as
necessary at regular intervals. The frequency of servicing will
depend upon the particular installation conditions and usage,
but in general once a year should be enough.
If this appliance is installed in a rented property there is a duty
or care imposed on the owner of the property by the current
issue of The Gas Safety (Installation and Use) Regulations,
Section 35.
It is the law that any servicing is carried out by a competent
person.
To obtain service, please call your installer or Heatcall (Glow-
worm’s own Service Organisation) using the telephone number
given on the controls tray.
Please be advised that the ‘Benchmark’ logbook should be
completed by the installation engineer on completion of
commissioning and servicing.
All CORGI Registered Installers carry a CORGI ID card, and
have a registration number. Both should be recorded in your
boiler Logbook. You can check your installer is CORGI registered
by calling CORGI direct on :- 01256 372300.
Boiler Clearances
If fixtures are positioned close to the boiler space must be left
as shown in diagram 2. At least a minimum clearance of 500mm
must be left in front of the boiler to allow for servicing.
Boilers Installed in a Compartment or
Cupboard
If the boiler is installed in a compartment or cupboard do not
obstruct any ventilation openings.
Do not use the compartment or cupboard for storage.
Cleaning
WARNING. This appliance contains metal parts (components)
and care should be taken when handling and cleaning, with
particular regard to edges.
Clean the casing occasionally by wiping it over with a damp
cloth or dry polishing duster.
Do not use an abrasive cleaner.
Boiler Electrical Supply
WARNING. This boiler must be earthed.
The boiler must only be connected to a 230V~50Hz supply
protected by a 3A fuse.
All wiring must be in accordance with the current issue of
BS7671.
Wiring to the boiler must be PVC insulated type to the current
issue of BS6500 Table 16, not less than 0.75mm2(24/0.20mm).
The colours of three core flexible cable are:
Brown - live, Blue - neutral,
Green/yellow - earth.
As the markings on your plug may not correspond with these
colours continue as follows:
The cable coloured blue must be connected to the terminal
marked “N” or black.
Instructions for Use
4140
Diagram 1
4625
CONTROLS COVER
DATA &
SERIAL
NUMBER
LABEL
RESET
BUTTON
30FF to 60FF Ultimate User Controls illustrated, details
for the 70FF to 120FF are different but the controls are
the same.
VIEWING WINDOW
SETTING POINT
CONTROL
THERMOSTAT
KNOB GAS SERVICE
COCK (Shown
Off)
The cable coloured brown must be connected to the terminal
marked “L” or red.
The cable coloured green/yellow must be connected to the
terminal marked “E”, or green or the earth symbol .

5221966B
0208M
6mm
6mm
65mm
6mm
6mm
6mm
160mm
500mm
Additional clearances may be
required for installation
FRONT
VIEW
Diagram 2
To Light the Boiler
WARNING. Sealed Systems
A sealed water system must be filled and pressurised by a
competent person.
Only light the boiler when you are sure that the system has been
filled and pressurised.
The pressure gauge should show at least 0.7bar, anything less
than this figure could indicate a leak and you MUST contact your
installation/servicing company.
If there is any doubt about the boiler being full of water consult
your installation/servicing company.
ALL SYSTEMS.
Turn the electrical supply on to the boiler and check that all
remote controls are calling for heat.
To Turn the Boiler On
Remove the controls cover, by withdrawing it forward and off,
see diagram 1.
Turn the control thermostat knob clockwise to any position
between MIN and MAX. The maximum temperature setting is
about 82oC (180oF), see diagram 1.
The boiler lighting operation is now automatic as follows.
The fan operates, followed by an ignition spark until the pilot is
lit. When the pilot is alight the ignition system switches off and
the main burner lights. The flames can be seen through the
viewing window, see diagram 1.
The main burner will remain alight until switched off by the
control thermostat or any remote control.
If the boiler is switched OFF, by hand, wait at least 30 seconds
before switching on again.
When the boiler switches off, both the pilot and main burner go
out.
The automatic lighting sequence will operate again when heat
is required.
Refit the controls cover.
It should be noted that this is a fan flue appliance and fan
operation may be heard.
To Turn the Boiler Off
For short periods, turn the control thermostat knob anti-clockwise
to “O” Off. To relight, turn the control thermostat knob to any
position between “MIN” and “MAX”.
For longer periods, turn the control thermostat knob fully anti-
clockwise to “O” Off and switch off the electrical supply to the
boiler.
To relight follow the lighting sequence given above.
Protection Against Freezing.
If the boiler is to be out of use for any long period of time during
severe weather conditions we recommend that the whole of the
system, including the boiler, be drained off to avoid the risk of
freezing up. Make sure that, if fitted, the immersion heater in the
cylinder is switched off.
For the position of the serial number, see diagram 1.
Instructions for Use

6
221966B
Diagram 1.1
SIDE ELEVATION FRONT ELEVATION
B
AO
C
P
L
C
L
M
F
G
H
PUMPED FLOW PUMPED RETURN
K
0301M
;
;
;
;
;
;
;
;
JWATER CONNECTIONS
28mm COPPER PIPE
GAS CONNECTIONS
RC1/2(1/2in. BSPT)
MODEL ABCDEFGHJKLMO
100FF,120FF 67 300 58 127 114 450 168 132.5 835 772 63 132 43
P
78.5
D
E
Important Notice
This boiler is for use only on G20 gas.
This boiler can be used on an open vented or sealed water
system.
When used on an open vented system domestic hot water can
only be provided by pumped circulation to the indirect cylinder.
Wherever possible, all materials, appliances and components
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 this boiler care should
be taken when handling sheet metal parts, to avoid any possibility
of personal injury.
1.1 Statutory Requirements
The installation of the boiler must be carried out by a competent
person in accordance with the relevant requirements of the
current issue of:-
Manufacturer’s instructions, supplied.
The Gas Safety (Installation and Use) Regulations, The Building
Regulations, The Building Standards (Scotland) Regulations
(applicable in Scotland), Local Water Company Byelaws, The
Health and Safety at Work Act, Control of Substances Hazardous
to Health, The Electricity at Work Regulations and any local
regulations which may apply.
Detailed recommendations are contained in the current issue of
the following British Standards and Codes of Practice:-
BS6798, BS5440 Part 1 and 2, BS5546 Part 1, BS5449,
BS6891, BS6700, BS7478, BS7593, BS7671.
Manufacturer’s instructions must not be taken as overriding
statutory requirements.
1.2 Data
See Table 1
All dimensions are given in millimetres (except as noted).
The Seasonal Efficiency Domestic Boilers UK (SEDBUK) is
Ultimate 100FF = 79, Ultimate 120FF = 78.1.
The value is used in the UK Government’s Standard Assessment
Procedure (SAP) for energy rating of dwellings. The test data
from which it has been calculated have been certified by B.S.I.
1 General

7221966B
1.3 Range Rating
This boiler is range rated and may be adjusted to suit individual
system requirements.
Table 2 gives the ratings and settings.
*Note: Lift weight is with Flue Elbow, Controls Cover and Front
Cover removed.
1.4 B.S.I. Certification
This boiler is certificated to the current issue of BS6332 Part 1,
invoking the current issue of BS5258 Part 1 for performance
and safety. It is, therefore, important that no alteration is made
to this 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 of the boiler, warranty
and could also infringe the current issue of the Statutory
Requirements.
1.5 Gas Supply
The gas installation shall be in accordance with the current
issue of BS6891.
The supply from the governed meter must be of adequate size
to provide a steady inlet working pressure of 20mbar (8in wg) at
the boiler.
On completion test the gas installation for soundness using the
pressure drop method and suitable leak detection fluid, purge
in accordance with the above standard.
1.6 Electrical Supply
WARNING. This boiler must be earthed.
All system components shall be of an approved type and shall
comply with and 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
26.44
90,210
32.38
110,485
23.45
80,000
29.31
100,000
33.43
114,066
39.6
135,150
29.3
100,000
35.17
120,000
3.5
125
4.2
148
29.24
99,760
26.38
90,000
9.2
3.7
14.4
5.8
11.6
4.7
2.8
100
3.5
123
3.1
111
205727
4.7mm
TABLE 2. 100FF
RANGE RATING
NOMINAL
HEAT
INPUT(NETT)
Min. Max.Med.
NOMINAL
HEAT
OUTPUT
APPROX.
GAS
RATE
BURNER INJECTOR MARKING:
kW
Btu/h
kW
Btu/h
m3/h
ft3/h
BURNER INJECTOR SIZE:
TABLE 2. 120FF
RANGE RATING
NOMINAL
HEAT
INPUT(NETT)
Min. Max.
36.52
124,608
32.24
110,000
3.9
137
Medium.
NOMINAL
HEAT
OUTPUT
APPROX.
GAS
RATE
BURNER INJECTOR MARKING: 205726
kW
Btu/h
kW
Btu/h
m3/h
ft3/h
9.9
4.0
14.2
5.7
12.0
4.8
BURNER.
SETTING
PRESSURE
BURNER.
SETTING
PRESSURE
m bar
in. wg.
m bar
in. wg.
BURNER INJECTOR SIZE: 5.2mm
3A, maximum. This method of connection must be by a fused
double pole isolating switch with a minimum contact separation
of 3mm on both poles. The switch should be readily accessible
and preferably adjacent to the appliance. It should supply the
appliance only and be easilyidentifiable as so doing.
Alternatively, an unswitched shuttered socket outlet and 3A
fused 3 pin plug both to the current issue of BS1363 may be
used, provided that they are not used in a room containing a
bath or shower.
Wiring to the boiler must be PVC insulated type to the current
issue of BS6500 Table 16.
1.7 Contents of Packaging
The boiler is delivered in one pack, refer to Section 4.1 for
contents.
Refer to Section 4.2 to check that the flue terminal assembly
supplied is suitable.
1 General
DATA TABLE 1.
MODEL
TOTAL DRY
WEIGHT
(Including
Terminal)
LIFT WEIGHT
WATER
CONTENT
GAS
CONNECTION
ELECTRICITY
RATING
WATER
CONNECTION
ELECTRICITY
SUPPLY
DATA LABEL
100FF
Rc 1/2in.
71W 97W
Internal fuse F1 & F2 (F1A)
2x28mm copper pipes from
top of case
230V~50Hz, fused 3A
Bottom right hand side of case
71.0 kg
(157 lb)
120FF
71.0 kg
(157 lb)
63.3 kg
(140 lb)
63.3 kg
(140 lb)
3.8 litres
(0.84 gal)
3.8 litres
(0.84 gal)
9072
*
9715

8
221966B
1.8 Water System
This boiler may be fitted to an open vented or sealed water
system.
It is recommended that plastic pipes for primary pipework
should not be used for this boiler.
1.9 Drain
System
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.
Draining taps should be to the current issue of BS2879.
Boiler
A draining point is fitted at the bottom right hand side of the heat
exchanger.
Cover controls to avoid water damage.
If required remove the combustion chamber front cover to
improve access.
1.10 Safety Valve
A safety valve need not be fitted to an open vented system.
1.11 Location
This boiler is not suitable for outdoor installation.
This boiler may be installed in any room, although particular
attention is drawn to the requirements of the current issue of
BS7671 with respect to the installation of a boiler in a room
containing a bath or shower. Any electrical switch or boiler
control utilising mains electricity should be placed so that it
cannot be touched by a person using the bath or shower. The
electrical provisions of the Building Standards (Scotland) apply
to such installations in Scotland.
The boiler must be mounted on a flat wall which is sufficiently
robust to take its total weight.
The boiler may be fitted to a wall made of combustible material.
1.12 Boiler Clearances
Refer to diagram 1.2.
The boiler must be positioned so that at least the minimum
operational and servicing clearances are provided.
Additional clearances may be required for installation.
If fixtures are positioned next to the boiler they should be made
removable for access to pipework.
Sufficient clearance must be left in front of the boiler for
servicing.
1.13 Room Ventilation
The boiler is room sealed and does not require the room or
space containing it to have permanent airvents.
1.14 Boilers in a Compartment
Where the installation of the boiler will be in an unusual position,
special requirements are needed, the current issue of BS6798
gives detailed guidance on these requirements.
A compartment used to enclose the boiler must be designed
and constructed specifically for this purpose. An existing
cupboard or compartment modified for the purpose may be
used. Details of essential requirements for cupboard or
compartment design are given in the current issue of BS6798.
The doorway opening should be of sufficient size to allow for
easy removal of the boiler.
Where the boiler is fitted in a cupboard or compartment,
permanent high and low level ventilation must be provided. The
minimum ventilation areas are given in Table 3.
1.15 Timber Frame Building
If the boiler is to be installed in a timber frame building it should
be fitted in accordance with the Institute of Gas Engineers
document IGE/UP/7/1998. If in doubt seek advice from the local
gas undertaking or Hepworth Heating Ltd.
1.16 Heating System Controls
The heating system should have installed: a programmer and
room thermostat controlling the boiler.
Thermostatic radiator valves may be installed, however they
must not be fitted in a room where the room thermostat is
located.
Note: For further information, see The Building Regulations
1991 - Conservation of fuel and power, 1995 edition - Appendix
G, table 4b.
0208M
6mm
6mm
65mm
6mm
6mm
6mm
160mm
500mm
Additional clearances may be
required for installation
FRONT
VIEW
MINIMUM CLEARANCES FROM WALLS
CEILING, FLOOR, CUPBOARD, WORKTOPS,
AND INFLAMMABLE MATERIALS
PLAN
VIEW
TABLE 3. COMPARTMENT AIR VENTS
VENTILATION
REQUIREMENTS
VENTILATION
FROM
ROOM
OR SPACE
MODEL
VENTILATION
FROM
OUTSIDE
100FF
HIGH LEVEL
VENT AREA
LOW LEVEL
VENT AREA
100FF 330 51 330 51
396 61.5 396 61.5
cm
2
in
2
cm
2
in
2
120FF
120FF
165 25.5 165 25.5
198 30.5 198 30.5
0209M
Diagram 1.2
1 General

9221966B
Note. Detailed recommendations for flues are given in the
current issue of BS5440 Part 1.
2.1 Terminal Position
The minimum acceptable siting dimensions for the terminal
from obstructions, other terminals and ventilation openings are
shown in diagram 2.1.
The terminal must be exposed to the external air, the position
allowing free passage of air across it at all times.
Car ports or similar extensions of a roof only, or a roof and one
wall, require special consideration with respect to any openings,
doors, vents or windows under the roof. Care is required to
protect the roof if it is made of plastic sheeting. If the car port
consists of a roof and two or more walls, seek advice from the
local gas company before installing the boiler.
If the terminal is fitted within 600mm below plastic guttering or
painted soffit an aluminium shield 1500mm long should be fitted
immediately beneath the guttering or eaves. If the terminal is
fitted within 450mm below painted eaves or a painted gutter, an
aluminium shield 750mm long should be fitted immediately
beneath the guttering or eaves.
2.2 Terminal Guard
A terminal guard is required if persons could come into contact
with the terminal or the terminal could be subject to damage.
If a terminal guard is required, it must be positioned to provide
a minimum of 50mm clearance from any part of the terminal and
be central over the terminal.
A suitable guard, reference Type K3, can be obtained from:
Tower Flue Components Ltd
Morley Road
Tonbridge
Kent
TN9 1RA
Under Car Port etc.
H,I
JD
F
K
Diagram 2.1
0103M
4307
A
A
F
GE
A
G
G
G
B,C B,C
FF
K
K
K
C
G
LL
2 Flue Terminal
MINIMUM SITING DIMENSIONS FOR
FANNED FLUE TERMINALS POSITION
A DIRECTLY BELOW, ABOVE OR HORIZONTALLY
TO AN OPENING, AIR BRICK, OPENING WINDOWS,
AIR VENT OR ANY OTHER
VENTILATION OPENING. 300
B BELOW GUTTER, DRAIN/SOIL PIPE 75
C BELOW EAVES 200
D BELOW A BALCONY OR CAR PORT 200
E FROM VERTICAL DRAIN PIPES AND SOIL PIPES 25
F FROM EXTERNAL CORNERS 25
G ABOVE ADJACENT GROUND OR BALCONY LEVEL 25
H FROM A SURFACE FACING THE TERMINAL 600
I FACING TERMINALS 1200
J FROM OPENING (DOOR/WINDOW) IN
CAR PORT INTO DWELLING 1200
K VERTICAL FROM A TERMINAL 1500
L HORIZONTALLY FROM A TERMINAL 300
M FROM INTERNAL CORNERS 25
MINIMUM
SPACING in mm
M

10
221966B
The installation of the boiler must comply with the requirements
of the current issue of BS6798.
It is recommended that plastic pipes for primary pipework
should not be used for this boiler.
3.1 Frost Protection
If the position of the boiler is such that it may be vulnerable to
freezing it should be protected as specified in the current issue
of BS5422. It is recommended that a frost protection thermostat
be fitted.
3.2 Pump
The pump, with integral valves, should be fitted in the heating
flow pipework from the boiler, it should be set to produce a
temperature difference of 11oC (20o), between the flow and
return, with the control thermostat set at “MAX”, which is about
82oC (180oF).
The pressure loss of the boiler can be found from diagram 3.1.
High resistance microbore systems may require a higher duty
pump.
3.3 Bypass - Fully Pumped and Sealed Water
System
A bypass MUST be fitted to a fully pumped and sealed water
system.
Where the water system allows the boiler and pump to operate
on bypass only, the bypass connection must be at least 2.5metres
away from the boiler.
The flow through the boiler must not be allowed to fall such that
there is a temperature difference greater than 20oC between the
flow and return.
3.4 Water System
For an open vented system the boiler must be supplied from an
unrestricted water supply taken from a feed and expansion
cistern fitted at a maximum height of 27metres above the boiler.
The cold feed must be 15mm minimum size.
It is important that the relative positions of the pump, cold feed
and open vent are as shown in diagram 3.2.
The unrestricted open vent from the boiler must rise continuously
to over the feed and expansion cistern.
3.5 Domestic Hot Water System
General. The domestic hot water service must be in accordance
with the current issue of BS5546, refer also to the current issue
of BS6700.
3.6 Indirect Cylinder
For all systems supplying domestic hot water the cylinder must
be indirect. It is recommended that the indirect cylinder be fitted
with some form of temperature control.
3.7 Fully Pumped Heating and Domestic Hot
Water
The connections for this type of system MUST be as shown in
diagram 3.2 and 3.3.
3.8 Inhibitor
Attention is drawn to the current issue of BS5449 and BS7593
on the use of inhibitors in central heating systems.
If an inhibitor is to be used, contact a manufacturer or Hepworth
Heating Ltd., for their recommendations as to the best product
to use.
When installing in an existing system take special care to drain
the entire system, including the radiators, then thoroughly
cleaning out before installing the boiler whether or not adding an
inhibitor.
3.9 Sealed Water Systems
The installation should comply with the appropriate requirements
of the current issue of BS4814, BS5449, BS6759, BS6798 and
BS7074 Part 1 and 2, see diagram 3.4 for a suggested layout.
3.10 Safety Valve
A safety valve must be fitted to a sealed water system.
It shall be preset, nonadjustable with a lift pressure of 3bar,
incorporating seating of 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.
Diagram 3.1
Flow rate (litres/minute)
Water pressure loss
(mm head of water)
PRESSURE LOSS
OF BOILER 100FF/120FF
Design Flow Rate
0088(z)M
750
500
250
0
0 5 10 15 20 25 30 35 40 45
700mm (120FF)
450mm (100FF)
3 Water Systems

11 221966B
3.11 Expansion Vessel
A diaphragm type expansion vessel, conforming to the current
issue of BS4814 (see also BS7074 Part 1 and 2) must be
connected at a point close to the inlet side of the circulating
pump, see diagram 3.4, unless laid down differently by the
manufacturer.
The expansion vessel volume depends upon the total water
system volume and the initial system design pressure. For any
system an accurate calculation of the vessel size is given in the
current issue of BS7074 Part 1.
Example. For an initial system design pressure of 0.7bar the
minimum total vessel volume required is 0.063xTotal System
volume.
Note. A higher initial design pressure requires a larger volume
expansion vessel.
Guidance on vessel sizing is also given in the current issue of
BS5449 and BS7074 Part 1.
The charge pressure must not be less than the static head of the
system, that is, the height of the highest point of the system
above the expansion vessel.
The water content of the boiler is given in Data Table 1.
3.12 Pressure Gauge
A pressure gauge with a set pointer and covering at least the
range of 0 to 4bar (0 to 60lb/in2) shall be permanently fitted to
the system in a position where it can be seen when filling the
system.
Diagram 3.2
6349
FEED AND
EXPANSION
CISTERN
22mm VENT
(MIN.)
15mm (MINIMUM)
COLD FEED
OPEN VENTED FULLY PUMPED WATER SYSTEM
RECOMMENDED RELATIONSHIP BETWEEN
PUMP COLD FEED AND VENT
450mm
MIN.
HEIGHT
1150mm
MIN.
RETURN FLOW
CYLINDER
PUMP
HEATING
150mm
MAX.
There must
always be a
cold water
path to the
return
connection
of the boiler. BOILER 28mm (MINIMUM)
BY-PASS WITH
LOCKSHIELD VALVE
FLOW
RET.
Diagram 3.3
28mm
PIPE
FLOW RETURN
4273
1metre Min.
27 metres
Max.
22mm FOR COMBINED FEED & VENT
TO BE FITTED IN ACCORDANCE
WITH BS 5449
INDIRECT
CYLINDER
ALTERNATIVE
SYSTEM
CONTROL
VALVES
HEATING
SYSTEM
PUMP
FULLY PUMPED CIRCULATION
BYPASS (DIAGRAMMATIC)
BYPASS 28mm
MIN WITH
LOCKSHIELD
VALVE
1metre Min.
27 metres
Max.
INDIRECT
CYLINDER
ALTERNATIVE
SYSTEM
CONTROL
VALVES
HEATING
SYSTEM
PUMP
FULLY PUMPED CIRCULATION
BYPASS (DIAGRAMMATIC)
BYPASS 28mm
MIN WITH
LOCKSHIELD
VALVE
22mm VENT & 15mm COLD FEED
TO BE FITTED IN ACCORDANCE
WITH BS 5449
6459
6466
3 Water Systems

12
221966B
3.13 Domestic Hot Water Cylinder
SINGLE FEED INDIRECT CYLINDERS ARE NOT SUITABLE.
The domestic hot water cylinder must be if the indirect coil type.
It must be suitable for working at a gauge pressure of 0.35bar
above the safety valve setting.
3.14 Domestic Hot Water System - Unvented
Where a storage system will not have a vent to atmosphere the
installation must comply with Building Regulations and the
Local Water Company Byelaws, see also the current issue of
BS6700.
If fitting into an existing system, the local authority must also be
advised.
3.15 Filling a Sealed Water System
Provision for filling the system at low level must be made. Three
methods are shown in diagram 3.5. There must be no permanent
connection to the mains water supply, even through a non-
return valve.
3.16 Water Makeup
Provision must be made for replacing water lost from the
system. A make up vessel mounted above the highest point of
the system and connected through a non-return valve to the
system on the return side of either the hot water cylinder or
heating system, see diagram 3.4.
Alternatively provision for make up can be made by a filling loop.
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
22mm (min)
BY-PASS WITH
LOCKSHIELD
VALVE
RETURN
Diagram 3.4
6252
(Make-up
alternatives)
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
0051M
Diagram 3.5
3 Water Systems

13 221966B
4.1 Unpacking
Open the carton, check the items supplied against the boiler
pack contents list on the flap, see diagram 4.1.
4.2 Flue Position and Length
Determine flue applications, length and terminal position before
starting.
Refer to diagram 4.2 or 4.3.
Note. If a longer flue duct is required DO NOT extend the
ducting.
A 1, 2 or 3metre flue system and terminal MUST be used, for the
100FF and 1 or 2 metre only for the 120FF.
Note: If required, an optional Wall Liner Kit, part No.452481, is
available, complete with fixing instructions.
4.3 Flue Preparation
All flue assemblies are designed for internal installation (optional
wall liner is required), given that there is sufficient clearances
opposite to the flue for the installation of the flue.
If there is insufficient clearance the flue can be installed from
outside.
Diagram 4.3
6854
Diagram 4.1
4792
CARTON
Standard Flue terminal illustrated.
MOUNTING
BRACKET INSTRUCTIONS
LOOSE
ITEMS PACK
BOILER
WALL
TEMPLATE
'S'
SIDE FLUE LENGTHS
Distance S = External wall face to boiler case
STD. 81mm to 346mm
1M 81mm to 830mm
2M 81mm to 1830mm
*3M 81mm to 2830mm *100FF ONLY
Diagram 4.2
4275
Standard Flue terminal illustrated.
REAR FLUE LENGTHS
Distance R = Wall thickness
STD. 75mm to 438mm
1M 75mm to 928mm
2M 75mm to 1928mm
*3M 75mm to 2928mm *100FF ONLY
'R'
For a wall thickness up to 300mm, provided that there is
sufficient space and the optional wall liner kit is used the flue can
be fully installed from the inside.
For a wall thickness of over 300mm the external flue hole will
need to be made good from the outside. This applies also if you
use the flue kit without the optional kit, irrespective of wall
thickness.
4 Flue and Appliance Preparation

14
221966B
4.4. Rear and Side Flue Application
Take the template from the boiler pack and position it on the
wall, making sure that the minimum clearances are maintained,
see diagram 1.2.
For a rear flue mark the position of the flue as diagram 4.4.
For a side flue, extend the centre line horizontally left or right to
the corner of the adjacent surface where the flue is required to
exit. Mark the position of the centre of the flue and boiler, then
remove template as diagram 4.4.
4.5 Flue Hole Cutting
Having marked out the flue centre cut a hole for the flue using,
preferably, a 120mm minimum core drill.
4.6 Wall Mounting Bracket
Reposition the template, making sure of dimensional alignment
with the flue hole.
Mark the boiler fixing points and mounting bracket position, see
diagram 4.5.
Note, the mounting bracket has additional holes to allow for
further fixings should site conditions require it.
Drill holes and plug, to suit No.12x2in woodscrews, fit the
screws allowing sufficient clearance, about 5mm, to accept the
swing brackets, see diagram 4.5.
Secure the mounting bracket to the wall with No.12x2in
woodscrews and plugs, see diagram 4.5.
If the boiler is not to be fitted for some time, cover the hole in the
wall.
Diagram 4.4
120 mm
MINIMUM
HOLE
127mm
SIDE FLUE
FLUE/BOILER
CENTRE LINE
4277
Diagram 4.5
7dia.
TEMPLATE
BOILER
MOUNTING
BRACKET
FLUE/BOILER
CENTRELINE
5mm
3/16in. dia.
PLUG
NO.
12x2in.
MOUNTING
BRACKET FIXING
POINTS
FLUE/BOILER
CENTRELINE
194
172
65.5
749
TOP BOILER
MOUNTING
HOLES
172.5
172.5
4278
4 Flue and Appliance Preparation

15 221966B
4.7 Flue Length
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 4.2.
For a side flue, measure the distance from the outside wall face
to the boiler centre line. Check that the flue length will be
suitable, see diagram 4.3.
All 2 and 3 metre flue systems are installed in a similar manner
to the standard flue.
4.8 Rear Flue
Mark the air duct/terminal assembly and the flue duct at the
length shown in diagram 4.6 and 4.8 then cut to length, cutting
square and removing any burrs.
Note, do not cut the flue duct at the pre-drilled end.
4.9 Side Flue
Mark the air duct/terminal assembly and the flue duct at the
lengths shown in diagram 4.7 and 4.9 then cut to length, cutting
square and removing any burrs.
Note, do not cut the flue duct at the pre-drilled end.
4.10 Flue Assembly
Locate the flue duct (drilled end) onto the flue elbow and secure
with the screws supplied in the loose items pack, see diagram
4.10.
Locate the flue duct/elbow into the air duct/terminal spigot and
the air duct/terminal into the flue elbow making sure the correct
alignment of top. Drill the air duct and secure/seal (external
fixing, do not seal) as shown in diagram 4.10.
4.11 Wall Liner
If a wall liner is used, fit foam seal as diagram 4.11.
Diagram 4.6
Diagram 4.7
Diagram 4.8
FLUE
DUCT
Q PLUS 72mm
Q
BOILER
CENTRE
LINE
T MINUS 55mm
Q PLUS 72mm
LONG FLUE
TERMINAL
STANDARD FLUE
TERMINAL
Q
T
6855
6856
6857
4 Flue and Appliance Preparation

16
221966B
Diagram 4.9
T MINUS 55mm
BOILER
CENTRE
LINE
LONG FLUE
TERMINAL
STANDARD FLUE
TERMINAL
T
6858
Diagram 4.10
NOTE:
THE FLUE TERMINAL
RESTRICTOR MUST BE
POSITIONED AS SHOWN
SECURING
SCREW (2)
FLUE ELBOW
FLUE DUCT SEALING TAPE
AIR DUCT/
TERMINAL
FLUE ELBOW
DUCT
STANDARD FLUE TERMINAL
3mm
DRILL
4284
Diagram 4.11
WALL THICKNESS-
UP TO 300mm
Q
FOAM
SEAL
WALL THICKNESS-
OVER 300mm
20mm
FOAM
SEAL
Q
Q MINUS 55mm
6859
4 Flue and Appliance Preparation

17 221966B
5.1 Boiler Preparation
With the boiler still in the bottom tray, slide the controls cover
upwards and remove it as shown in diagram 5.1.
Remove the front cover by undoing (and keeping) the wing nut,
nut and shakeproof washer, then lift the front cover off, see
diagram 5.1.
Place the front cover on one side until required, having removed
the polystyrene packing piece.
Fit suitable compression fittings to the boiler connections.
5.2 Mounting the Boiler
Make sure that the top, swing brackets are UPRIGHT.
Lift the boiler into position, hooking over the mounting bracket.
Swing the brackets over the two screws at the top. Hold the
swing bracket(s) in place whilst tightening the screw(s) on to it,
see diagram 5.2.
Remove the blue and red electrical connections from the fan,
see diagram 5.3.
Diagram 5.1 Diagram 5.2
CONTROLS
COVER
FRONT
COVER
SHAKEPROOF
WASHER
NUT
WING
NUT 5mm
Pipe
omitted
for clarity
4285
4286
MOUNTING
BRACKET
SWING
BRACKET
SECURING
SCREWS (2)
Break the air pressure switch tube connections from the fan,
see diagram 5.3.
Remove the fan assembly by removing the screws and sliding
out, see diagram 5.3. Take care not to damage the gasket.
Slacken, but do not remove, the flue hood securing screws, see
diagram 5.4.
5 Boiler Installation

18
221966B
5.3 Water Circulation System
Complete the water connections to the boiler.
Fill, vent and flush system.
Check for any leaks and put right.
5.4 Safety Valve Discharge
Fit a suitable discharge pipe to the safety valve and route it
outside the building so that any discharge can be seen but will
not cause injury to person, damage to property or any electrical
installation.
5.5 Gas Connection
Make the gas connection to the Rc 1/2in gas service cock, see
diagram 5.5.
Check for leaks using a suitable leak detection fluid.
Diagram 5.5
Diagram 5.3
CLEAR
RED
FLUE HOOD
SECURING
SCREW (4)
FAN SECURING
SCREWS
FAN
ASSEMBLY
AIR PRESSURE
SENSING PIPES
CLEAR
ELECTRICAL
CONNECTIONS
Diagram 5.4
FLUE HOOD
SECURING SCREWS (4)
FAN
SECURING
BRACKET
FLUE
HOOD
GAS SERVICE COCK
(SHOWN OFF)
UNION NUT
4287
4289 4288
5 Boiler Installation

19 221966B
Note. If external flue fixing is required start at 6.2.
6.1 Flue Fixing - Internal
Note : Use of the optional wall liner kit is required.
Place the flue assembly into the hole. Check that the flue
terminal is correctly positioned and is the distance required from
the outside wall face, see diagram 6.1.
Position flue elbow gasket and secure the flue assembly to the
boiler using the dogpoint screws, see diagram 6.2.
Make sure of the correct fitting of the flue to the boiler.
Now continue at Section 6.3.
6.2 Flue Fixing - External
Remove the flue elbow from the air duct/terminal and flue duct,
by removing and keeping, the securing screw(s).
From outside place the air duct/terminal and flue duct assembly
into the hole and make sure that the flue terminal is correctly
positioned and is the distance required from outside wall face,
see diagram 6.1.
Position flue elbow gasket and secure the flue elbow to the
boiler using the dogpoint screws, see diagram 6.2.
Make sure of the correct fitting of the flue to the boiler.
Pull the flue duct forwards and engage onto the flue elbow.
Push the air duct back into the wall to the dimension shown in
diagram 6.3.
Important, the flue duct will become disengaged should the
dimension be any greater than shown.
Hold the flue duct onto the flue elbow, then, secure the flue duct
to the flue elbow, see diagram 6.3.
Pull the air duct back to engage with
the flue elbow and secure/seal.
6.3 All Flue Installations
Fit the fan to the flue elbow spigot and secure with the screws
previously removed.
Reconnect the blue and red electrical connections to the fan,
the polarity of the connections is not important.
Reconnect the air pressure switch tubes as shown in diagram
5.3.
Secure the flue hood, see diagram 5.4.
Diagram 6.1
Diagram 6.3
152 DIA
CORE
DRILLED
HOLE
58
OUTSIDE
WALL FACE
FLUE
TERMINAL
AIR
DUCT
7005
✽ 30mm
WALL FACE
FLUE
ELBOW
FLUE DUCT
✽
30mm
FLUE
DUCT/
ELBOW
3mm Drill
Sealing
Tape
✽Maximum dimension! Otherwise the flue duct will
become disengaged.
Diagram 6.2
GASKET
FLUE ELBOW
SECURING
SCREW (4)
0181M
4290
6 Flue Fixing

20
221966B
7.1 Control Box Removal
Remove the electrical control box securing screws, see diagram
7.1. Slide the box forwards and release, hook it onto the lip
bracket at the front, see diagram 7.1.
7.2 Electrical Connection
WARNING. This boiler must be earthed.
Take care not to damage any internal wiring and capillaries.
Take the plastic cable retaining clip, from the loose items pack,
peel off the backing paper and position it in a suitable place to
secure the incoming cable.
Using heat resistant (to 85oC) cable of at least 0.75mm2(24/
0.2mm) to the current issue of BS6500 Table 16 and of suitable
length, thread through the cable clamps, secure into the plastic
clips and connect to appropriate terminals, see diagram 7.2 and
11.5.
Standard colours are, brown - live (L), blue - neutral (N) and
green and yellow - earth (E).
Make sure the cable is suitably secured.
When making connections, make sure that the earth conductor
is made of a greater length than the current carrying conductors,
so that if the cable is strained the earth conductor would be the
last to become disconnected.
NOTE. Open Vented Water Systems ONLY.
Bridge terminals K1 and K2.
7.3 Pump Connection
The pump must be connected directly to the control box, as
shown in diagram 7.2, threading the cable through the cable
clamp in the side of the control box.
7.4 External Controls
Any external controls must only be wired to interrupt the red link
between terminals SL and 9.
Make sure that the supply cable and all external cables are
secured and away from hot surfaces.
7.5 Testing
Checks to ensure electrical safety must be carried out by a
competent person.
After installation of the system, preliminary electrical system
checks as below should be carried out:
1. Test insulation resistance to earth.
2. Test earth continuity and short circuit of all cables.
3. Test the polarity of the mains.
The installer is requested to advise and give guidance to the
user of the controls scheme used with the boiler.
Diagram 7.2
Diagram 7.1
SECURING
SCREWS (2)
LIP BRACKET
MAINS
CABLE
CABLE
CLAMPS
MAINS
CABLE
✽
RED
LINK
✽Remove red link between 9 & SL when fitting
a time control etc (If no switch is fitted, link will
make the circulation pump run constantly).
PUMP
CABLE
PUMP
CABLE
NOTE: Bridge
terminal K1 & K2
on an Open
Vented System
only
IGNITION LEAD
9079
4136
7 Electrical Connectors