Potterton Kingfisher Mf CFL40 - 100 Installation and maintenance instructions

About the Boiler See inside cover for models covered by these instructions.
This Floor Mounted Fan Assisted Gas Boiler is available as Conventional or Balanced Flue.
This boiler is for use with Natural Gas (G20) only at 20mbar and for use in GB & IE.
About Safety The Gas Safety (Installation and Use) Regulations 1998.
‘‘ In your own interest, and that of safety, it is law that all gas appliances are installed by competent
persons, in accordance with the above regulations. Failure to install appliances correctly could
lead to prosecution.’’
Installation must be in accordance with the Installation & Service Instructions and the rules in
force.
LeavetheseinstructionsandtheBenchmarkLogBookwiththeuserforuseonfuturecalls.
Installation & Service Instructions Kingfisher Mf
RSL40 - 100, CFL40 -100
CON0005A
TM
The code of practice for the installation,
commissioning & servicing of central heating systems

Publication No. 5102977
2
Flame Lock-out Re-set
0
Control Panel Serial Number Badge
CON0092B
Data Badge
50 -100
Data Badge
40
Contents
Contents
TechnicalData........................................................3
Introduction..................................................................5
Health&SafetyInformation............................................5
Codesof Practice...........................................................5
1. InstallationRequirements................................6
1.1 GasSupply.......................................................6
1.2 ElectricitySupply..............................................6
1.3 LocationofBoiler..............................................6
1.4 Air Supply - CFL/RSL..................................7/9
1.5 Flue Systems - CFL/RSL.............................8/9
1.6 The System...................................................11
2. Installation...................................................15
2.1 InstalltheBoiler...............................................15
2.2 InstalltheFlue CFL.........................................15
Installthe Flue RSL........................................17
2.3 ConnecttheGas Supply.................................19
2.4 ConnecttheWater Supply..............................19
2.5 ConnectthePowerSupplyCable.....................20
2.6 InstalltheOptionalProgrammer......................21
3. Commissioning............................................22
3.1 CommissiontheBoiler....................................23
3.2 FinalAdjustments..........................................23
3.3 InstructtheUser.............................................24
3.4 AdvisetheUser..............................................24
4. Service&Replacementof Parts......................25
4.1 GeneralAccess.............................................26
4.2 Electronic ControlBoard..................................27
4.3 AirPressureSwitch........................................27
4.4 Temperature Sensor.......................................27
4.5 Overheat Thermostat......................................27
4.6 Burner, Gas Valve, Injector &
Electrode...................................................28
4.7 CombustionChamberInsulation......................29
4.8 Fan&Flue Hood.............................................29
4.9 Products Discharge Safety Device
-TTB(CFLModelsOnly).................................29
5. WiringDiagrams..............................................30
6. FaultFinding....................................................32
7. ShortListof Spares.........................................36
8. FlueKits&OptionalExtras...............................38
Theboilermodel and serial number aregiven
ontheboilerdatalabel which is located on the
heat exchanger cover plate.
The models covered by these instructions are:-
Kingfisher Mf CFL 40 - G.C. No. 41 590 24
Kingfisher Mf CFL 50 - G.C. No. 41 590 28
Kingfisher Mf CFL 60 - G.C. No. 41 590 29
Kingfisher Mf CFL 70 - G.C. No. 41 590 30
Kingfisher Mf CFL 80 - G.C. No. 41 590 31
Kingfisher Mf CFL 90 - G.C. No. 41 590 32
Kingfisher Mf CFL 100 - G.C. No. 41 590 34
Kingfisher Mf RSL 40 - G.C. No. 41 590 35
Kingfisher Mf RSL 50 - G.C. No. 41 590 36
Kingfisher Mf RSL 60 - G.C. No. 41 590 37
Kingfisher Mf RSL 70 - G.C. No. 41 590 38
Kingfisher Mf RSL 80 - G.C. No. 41 590 39
Kingfisher Mf RSL 90 - G.C. No. 41 590 40
Kingfisher Mf RSL 100 - G.C. No. 41 590 41
SAFETY, PERFORMANCE & QUALITY
Kingfisher Mf boilers have been assessed by a
Government appointed Notified Body and shown to
meet the 'Essential Requirements' of the European
Gas Appliance Directive.
The Directive lays down requirements for the safety
and efficiency of the appliance, together with its
design, construction, and use of materials.
It also requires the production process to be covered
by an approved and monitored system of quality
assurance.
Fig. 1
Pottertonisa member of theBenchmarkinitiative and
fullysupportstheaimsoftheprogramme. Benchmark
has been introduced to improve the standards of
installation and commissioning of central heating
systems in the UK and to encourage the regular
servicing of all central heating systems to ensure
safety and efficiency.
Important – Failure to install and commission this
appliance to manufacturer’s instructions may
invalidate the warranty. This note does not affect your
statutory rights.

Publication No. 5102977 3Technical Data
Technical Data
Heat Input & Efficiency
figures are quoted as gross
Boiler models
40 50 60 70 80 90 100
Maximum Rate
Output kW 11.72 14.65 17.58 20.52 23.45 26.38 29.31
Btu/h 40,000 50,000 60,000 70,000 80,000 90,000 100,000
Input kW 14.47 18.31 22.00 25.60 28.95 32.98 36.76
Btu/h 49,372 62,474 75,064 87,347 98,777 112,528 125,425
Gas rate m³/h 1.38 1.75 2.10 2.44 2.76 3.14 3.50
ft³/h 48.73 61.65 73.98 86.31 97.42 110.97 123.75
Efficiency % 81.0 80.0 80.0 80.0 81.0 80.0 79.7
BurnerPressure mbar 13.5 14.8 11.9 12.1 11.3 13.1 13.0
in wg 5.42 5.92 4.76 4.54 4.54 5.24 5.20
Injector Size mm 2.9 3.2 3.7 3.9 4.3 4.4 4.7
MaximumWorkingHead 30.5 m (3 bar)
MinimumWorkingHead 300 mm
Minimum Circulating Head - Gravity 1.2 m
Gas Supply Pressure 20mbar
Gas Supply Connection Rc. ½ (½ in BSP Female)
MaximumFlowTemperature 82 °C
FlowConnection 28 mm Copper
Return Connections - Gravity 28 mm Copper
Return Connections - Pumped 28 mm Copper
WaterContent 6.5 litres
Appliance Weight Installed - Dry 65.0 kg RSL / 69.0 kg CFL
Electricity Supply 230v ~ 50Hz Fused at 3A
InternalFuse Type 2 AT (2 off)
PowerConsumption 80 Watts (excluding pump)
Classifications CAT I 2H
2H G20 20 mbar
B22, C12, C32 (40 - 70 models)
B22, C12 (80 - 100 models)
IP20
NOx Class 1 - CFL90, 100 & RSL60, 70, 80, 90, 100 models
NOx Class 2 - CFL40, 60, 70, 80 & RSL40, 50 models
NOx Class 3 - CFL50 model
SEDBUK Declaration for Kingfisher
Model Seasonal Efficiency
(SEDBUK) (%)
RSL CFL
40 78.5 78.4
50 78.5 78.5
60 78.5 78.0
70 78.1 78.0
80 78.2 78.3
90 78.1 78.0
100 78.0 78.0
This 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 0086.

Publication No. 5102977
4 Technical Data
Fig. 2
CON0078B
CFL Flue
Outlet
Shown
(127 or
153 Outlet)
CFL Flue Outlet Shown
(Two Centres Available)
RSL Flue
Outlet
Shown
RSL Flue
Outlet Shown
25 Front Clearance
400 recommended
for servicing
(if non removable)
50-100
model
shown
103

Publication No. 5102977 5
Introduction
Introduction
The Gas Safety (Installation and Use) Regulations 1998.
This appliance must be installed and serviced by a
competent person, in accordance with the above
regulations.
IntheUK'Corgi'Registered Installers (including the regions
of British Gas Services) undertake to work to a safe and
satisfactory standard.
Failure to install appliances correctly could lead to
prosecution.
It is in your own interest, and that of safety, to ensure that
the regulations are complied with.
Kingfisher Mf boilers are fully automatically controlled,
floor standing, fan powered, balanced or conventional
flued appliances using a cast iron heat exchanger and are
availablein outputs rangingfrom 11.72 -29.31 kW (40,000
- 100,000 Btu/h)
The boilers are designed for use on fully pumped open
vented or sealed water systems with an indirect hot water
cylinder or open vented gravity systems. THEY MUST
NOT BE CONNECTED TO A DIRECT CYLINDER.
The boilers are for use on Natural Gas (G20) only.
Samples of the Kingfisher Mf gas boilers have been
examined by Advantica Technologies Limited, a United
Kingdom Notified Body. The range is certified to comply
with the essential requirements of the Gas Appliance
Directive 90/396/EEC, the Low Voltage Directive 72/23/
EEC and shows compliance with the Electro Magnetic
Compatibility Directive 89/336/EEC, the Boiler Efficiency
Directive 92/42/EEC and are therefore permitted to carry
the CE Mark.
Delivery & Kits Available
RSL Model is delivered in two packages (1) the boiler with
fittings and (2) the flue assembly.
CFL Model is delivered in one package.
Various flue kits and other options for the Kingfisher Mf
range of boilers are shown on Pages 38 & 39.
Health and Safety Information for the Installer
and Service Engineer
Under the Consumer Protection Act 1987 and Section 6
of the Health and Safety at Work Act 1974, we are required
to provide information on substances hazardous to health.
Small quantities of adhesives and sealants used in the
product are cured and present no known hazards.
The following substances are also present.
Insulation and Seals
Material - Man Made Mineral Fibre.
Description - Boards, Ropes, Gaskets.
Known Hazards - Some people can suffer reddening
and itching of the skin. Fibre entry into the eye will
cause foreign body irritation which can cause severe
irritation to people wearing contact lenses. Irritation to
respiratory tract.
Precautions - Dust goggles will protect eyes. People
with a history of skin complaints may be particularly
susceptible to irritation. High dust levels are only likely
to arise following harsh abrasion. In general, normal
handling and use will not present high risk, follow good
hygiene practices, wash hands before, touching eyes,
consuming food, drinking or using the toilet.
First Aid - Medical attention must be sought following
eye contact or prolonged reddening of the skin.
Codes of Practice
The boiler must be installed in accordance with: The Gas
Safety (Installation and Use) Regulations 1998 and the
current issue of:-
The Building Regulations, Building Standards (Scotland)
Regulations, Local Building Regulations, Model and local
Water Undertaking Bye-laws, IEE Wiring Regulations and
Health & Safety Document No. 635 "The Electricity at
WorkRegulations1989".
For Irelandinstall in accordance withI.S. 813 "Installation
of Gas Appliances".
IMPORTANT
This appliance has been certified for safety. It is therefore important that no external control device (e.g. flue
dampers, economisers, etc.) be directly connected to the appliance unless covered by these Installation &
Service Instructions or otherwise recommended in writing. Any direct connection of a control device not
approved by Potterton could invalidate the CE Certification and normal appliance warranty.

Publication No. 5102977
6 Installation Requirements
1. Installation Requirements
1.1 Gas Supply
The meter and supply pipes must be capable of delivering
thisquantityofgasinadditiontothedemandfromanyother
appliances in the house and must be governed at the
meter.
On 90 & 100 models, due to the gas flow rate required,
22mm gas supply pipe should be used up to the inlet
connection of the gas cock on the boiler.
Thecompleteinstallationmustbe tested for gas soundness
and purged as described in BS6891.
1.2 Electricity Supply
230V ~ 50Hz via a fused double pole switch with a contact
separation of at least 3 mm in both poles adjacent to the
boiler. Power consumption is approximately 80W. There
must be only one common isolator for the boiler and its
control system and it must provide complete electrical
isolation. A plug (if fitted) must be accessible to the user
after installation of the appliance.
Fuse the supply at 3 A. The minimum requirement for the
power supply cable is that it should be a PVC sheathed
cord at least 0.75 mm² (24 x 0.2 mm) (code designation
HO5 VV-F or HO5 VVH2-F) as specified in table 16 of
BS6500:1984.
All wiring external to the boiler shall comply with the latest
IEE Wiring Regulations, and any local regulations which
apply.
WARNING: THIS APPLIANCE MUST BE EARTHED.
In the event of an electrical fault after installation of the
boiler, preliminary electrical systems checks must be
carried out i.e. Earth Continuity, Short Circuit, Polarity and
Resistance to Earth.
1.3 Location of Boiler
Theboileris not suitable for external installation.Theboiler
must stand firm and level. No special floor protection is
needed,butfinisheswhichsoftenwhenwarme.g.linoleum
and plastic floor tiles should be removed or may be
protected by an insulating sheet at least 10mm thick.
The boiler must be installed so that the flue terminal is
exposed to the external air. It is important that the position
of the terminal allows the free passage of air across it at all
times.
The boiler is suitable for installation against a combustible
wall e.g. wood cladding, provided that the flue duct is not
closer than 25 mm to combustible material. A metal sleeve
should be installed to surround the flue duct to provide a
25mm annular space. Further guidance is given in
BS5440:1:2000,sub-clause 4.4.
If the boiler is to be installed in a timber framed building
it should be fitted in accordance with the Institute of Gas
Engineers document IGE/UP/7/1998 (also, British Gas
Service publication Part 19 - Building and Kitchen Work).
If in doubt advice must be sought from Potterton.
RSLboilersmaybeinstalledin anyroom,althoughparticular
attention is drawn to the requirements of the current IEE
WiringRegulations and,inScotland,theelectricalprovisions
of the Building Standards applicable in Scotland with
respect to the installation of the boiler in a room containing
a bath or shower.
CFL boilers must not be installed in bath, shower rooms, or
rooms used as sleeping accommodation.
RSLModels: Wherearoom-sealedapplianceisinstalledin
a room containing a bath or shower, any electrical switch
orappliancecontrol, utilising mains electricity should beso
situated that it cannot be touched by a person using the
bath or shower.
CFL Models: Conventional flue boilers can be installed
either in a kitchen or utility room or inside a suitably
ventilated, purpose designed or modified compartment.
Where the installation of the boiler will be in an unusual
position,specialproceduresmaybenecessary andBS6798
and BS5546 give detailed guidance on this aspect.
Acompartmentused to enclosetheboilermustbedesigned
and constructed specifically for this purpose. An existing
compartment may be used provided that it is modified for
the purpose. Details of essential features of compartment
design including airing cupboard installations are given in
BS6798 and BS5546 and should be complied with.
RSLModels: Iftheboilerisfittedunderaworksurfaceitmay
be located next to or between kitchen cabinets or fittings
providing that the front of the boiler case is visible and
unobstructed, the special requirements for an enclosed
compartment will not apply
If the boiler is to be fitted under a worksurface, the
worksurface may need to be removed to install the boiler.
It is advisable that the worksurface be removable to allow
access for servicing if required.
If the boiler is to be fitted in a run of kitchen units it is
recommended that the boiler is fitted first or the adjacent
units removed.

Publication No. 5102977 7Installation Requirements
The boiler requires the clearances shown in Fig. 2.
Conventional Flue Models - See Page 7 & 8.
Balanced Flue Models - See Pages 9 & 10.
Conventional Flue Models
1.4 Air Supply
The air requirements must meet BS 5440 Part 2.
Theroom in which the boiler is installedmust be ventilated.
Ventilation of the room containing the boiler shall include
air for combustion and correct operation of the flue (ie
Draught Diverter dilution).
A permanent air vent shall be provided in an outside wall
of the building either at high or low level in accordance with
Table 1.
The opening may be:
a) Directly into the room or space containing the boiler
or indirectly via an opening of at least the same
area.
b) Via a duct either directly into the room or space or
indirectly via an opening of at least the same free
area.
Where air is drawn indirectly from outside through more
than two air vents refer to BS 5440 Part 2.
Where an extraction fan is fitted in the room containing the
boiler, special ventilation requirements must be
implemented. Refer to BS 5440 Part 2.
Any grille and/or duct should be so sited and of a type not
to become easily blocked or flooded and should offer low
resistance to airflow.
If the boiler is installed in a compartment, permanent air
vents are required in the compartment, one at high level
and one at low level (Table 2), either direct to the outside
air or to a room.
Both high level and low level air vents must communicate
with the same room or must be on the same wall to outside
air.
If the boiler is installed in a compartment with a door, allow
at least 25 mm clearance between the front of the boiler
and door for air movement. All other clearances are as Fig.
2.
Fig. 3
Table 1
Combustion Air
Free Area cm sq.
CFL40 35
CFL50 51
CFL60 68
CFL70 84
CFL80 101
CFL90 117
CFL100 134
Table 2
Compartment Ventilation
Free Area cm sq. High Level Low Level
CFL40 132 264
CFL50 165 330
CFL60 198 396
CFL70 231 462
CFL80 264 528
CFL90 297 594
CFL100 331 662

Publication No. 5102977
8
1.5 Flue Systems
A flue system (lined throughout its length) must be
provided to evacuate the flue products of combustion
from the boiler. Reference should be made to the
building regulations and BS 5440:1. and the flue
system efficiency should be checked in accordance
with BS 5440.
Ideally a flue should rise vertically and any terminal or
terminationpoint shallbepositionedsothatcombustion
products can disperse safely at all times. Therefore
forpracticalpurposes,theflueshouldhavetheshortest
possible run to external atmosphere, with as near
verticalriseaspossible,90°bendsshouldbeavoided.
The terminal must be at least above roof level and of
a type approved by British Gas.
To achieve the best perfomance from the boiler there
should be at least 600 mm of vertical flue from the
boiler flue socket. If this is not achievable, a 125 mm
fluesizeshould be used irrespective of theboilersize.
Horizontal runs should be avoided, however if a near
horizontal flue run is unavoidable, the total vertical
height necessary should be calculated in accordance
with BS 5440:1.
If an existing chimney is used, ensure that it is
thoroughly swept before lining or connecting the
boiler. The liner must have an internal diameter of
100mm for the 40 to 60 models and 125mm for the 70
to 100 models.
Care should be taken to avoid condensation in the
flue.
Inthecase ofapre-linedchimney, itmustbeconnected
to the socket of the boiler flue hood with a length of
purpose made flue.
Wherefluesize is to be determined bycalculation,the
following information should be used
Next Section is 1.6 The System.
Installation Requirements
Fig. 4
Model
Size
40
50
60
70
80
90
100
Mass Rate of Combustion
Products (g/sec)
10.19
11.30
13.58
14.88
15.90
16.55
17.59
Average
Temp. (°C)
108
117
130
135
144
156
165
Seal
Liner
Approved
Ter mi nal
Cement
Seal Sealing
Plate
Set Into
Chimney
Pre-lined Flue
Seal
CON0011C
Purpose
Made
Flue
Purpose
Made Flue

Publication No. 5102977 9Installation Requirements
Balanced Flue Models
1.4 Air Supply
The air requirements must meet BS 5440 Part 2.
The room in which the boiler is installed does not require a
purpose provided air vent.
If the boiler is installed in a compartment, permanent air
vents are required in the compartment, one at high level
and one at low level, either direct to the outside air or to a
room. Both high level and low level air vents must
communicate with the same room or must be on the same
wall to outside air. Both the high level and low level vent
must each have a combined free area in accordance with
Table 3.
If the boiler is installed in a compartment with a door, allow
atleast25mmclearancebetweenthe front of the boiler and
the door for air movement.
1.5 Flue Systems & Terminal Location
Horizontal - Concentric (Left, Right or Rear).
The flue/terminal assembly supplied is suitable for a
wall thickness of between 150mm and 400mm.
A flue/terminal assembly suitable for a wall thickness of
up to 600mm is also available.
Both the flue/terminal assemblies are telescopic and
the minimum lengths (150 mm/6 in) are achieved by
cutting.
A1m flueextensionisavailable.Undernocircumstances
should the total flue length exceed:-
3.4m 40 to 70 models
2.4m 80 model
1.4m 90 model
1.0m 100 model
Vertical - Concentric.
3.4m 40 - 70 models Only
Where bends may be being used, the total flue length will
be reduced, see Pages 17 & 18 for more details.
See separate Installation Instructions supplied with the
flue.
Fig. 5
Table 3
Compartment Ventilation
Free Area cm sq. High Level Low Level
RSL40 132 132
RSL50 165 165
RSL60 198 198
RSL70 231 231
RSL80 264 264
RSL90 297 297
RSL100 331 331
Note: If ventilating directly to outside, the figures shown in
Table 3 can be halved.

Publication No. 5102977
10
• Where a horizontal flue is sited less than 2m
above a balcony, above ground, or above a flat
roof to which people have access, a suitable
terminal guard must be fitted. This serves two
purposes, to protect the terminal against damage
or interference and to protect passers-by. A
terminal guard is available (Sales Code:
PTERMGUARDEF), this should be fitted centrally
about the terminal.
Note: Where a flue terminal is installed less than
1 metre from a plastic, or painted gutter, or 500
mm from painted eaves, an aluminium shield 1
metre long, should be fitted to the underside of the
gutter or painted surface. A suitable wall plate
should be fitted to the painted wall surface of a
mobile home.
• IMPORTANT: It is absolutely ESSENTIAL, to
ensure that products of combustion discharging
from the terminal cannot re-enter the building, or
any other adjacent building, through ventilators,
windows, doors, natural air infiltration, or forced
ventilation/air conditioning. If products of
combustionarefound to bere-enteringany building,
the appliance MUST be turned OFF
IMMEDIATELY.
Installation Requirements
Fig. 6
M
G
G
H
F
L
G
AAF
J
K,N
D
E
J
Likely flue positions requiring
a flue terminal guard
C
Q
AG
K,N
G
FLU0002A
P
S
R
FannedDraughtBalancedFlue
ADirectly below an opening, air brick,
opening window etc
BAbove an opening, air brick, opening window, etc
CHorizontally to an opening, air brick,
opening window etc
DBelow a gutter, or sanitary pipework
EBelow the eaves
FBelow a balcony or carport roof
GAbove ground, roof or balcony level
HFrom vertical drain/soil pipe work
JFrom an internal or external corner
KFrom a surface facing a terminal
LVertically from a terminal on the same wall
MHorizontally from a terminal on the same wall
NFrom a terminal facing the terminal
PFrom an opening in a carport (e.g. door, windows)
into the building
QFrom adjacent wall to flue (vertical only)
RFrom internal corner to flue (vertical only)
SBelow eaves or balcony (vertical only)
Terminal Position with Minimum Distance (mm)
Note: The distance from a fanned draught appliance terminal installed
parallel to a boundary may not be less than 300 mm in accordance with
the diagram on the left.
300
300
300
75
200
200
300
150
300
600
1500
300
1200
1200
210
230
600
Top View Rear Flue Top View Side Flue
Terminal
Assembly
Property Boundary Line
Fanned DraughtFanned Draught
300 min. 300 min.
FLU0005A
Reduced Clearances
This range of boilers has been tested and approved for use with certain
clearances less than those shown above.
Only one of these reductions may be used on a single installation.
RSL40-70 RSL80-100
DBelow a gutter, or sanitary pipework 25 25
EBelow the eaves 25 25
FBelow a balcony or carport roof 25 25
HFrom vertical drain/soil pipe work 25 ---
JFrom an internal or external corner 25 ---

Publication No. 5102977 11Installation Requirements
1.6 The System
If plastic pipe is used for the central heating circuit there
mustbearunofatleast1m of uninsulated copper pipe from
the boiler flow and return connections.
The boiler must be used on INDIRECT hot water systems
only. It is suitable for use on open vented gravity domestic
hotwater/pumpedcentralheatingsystemsor, fully pumped
systems which may be sealed or open vented.
Existing systems should be thoroughly cleansed prior to
boiler installation.
The system should be designed so that the maximum
staticheaddoesnotexceed30.5m andthereisaminimum
on fully pumped systems of 300 mm. See Fig. 8.
Gravitydomestichotwatercircuitsshould have a minimum
circulating head of 1.2 m. See Fig. 7. Horizontal pipe runs
shouldbekepttoa minimum. To prevent reversecirculation
inthegravitycircuitwhen the pump isrunninganinjectortee
isincorporated.
The pump should preferably be fitted in the flow, though
installation in the return is acceptable providing care is
taken to ensure air is not drawn into the system due to the
negative pressure effects of the pump. Isolating valves
must be fitted as close as possible to allow replacement
without system draining.
Drain off taps should be fitted in the pipework close to the
boiler and in the low points of the system. A drain point is
alsoprovidedontheheatexchangershouldtheboilerneed
draining - see Fig. 22.
Combined Gravity Hot Water Pumped Central
Heating Systems.
It is recommended that a cylinder thermostat and zone
valve are used to control the temperature of the hot water
and that a by-pass be installed in the gravity circuit. A
suggestedmethodofdoing this is showninFig.7.wherethe
bathroom radiator is connected into the gravity circuit and
is fitted with two lockshield valves. Mechanically operated
thermostaticdomestichotwater temperature controlvalves
which allow the boiler to operate when the valve is closed
or partially closed MUST NOT BE FITTED UNLESS a
bypass radiator is fitted. Note: The boiler has one flow and
tworeturn connections.OncombinedgravityDHW/Pumped
central heating a Tee will be needed in the flow which must
be fitted directly to the connecting pipe provided.
Fully Pumped Systems
The pump must be wired directly to the terminal block (See
Fig.20)asitwillallowthepumptobe controlled by the over-
run device. This will ensure that the pump will continue to
run after boiler shut down thus preventing nuisance
operation of the overheat thermostat.
If a three port diverter valve is used as shown in Figs.8 &
9, a by-pass is not necessary since one circuit is always
open. Where a pair of two port valves are used, a by-pass
is necessary. It should be fitted with a lockshield valve and
be adjusted to maintain a minimum flow through the boiler
of 4.5 litres/min (1 gal/min) see Figs. 8 & 9.
Systems fitted with controls which allow the boiler to
operate when both the hot water and central heating
circuitsare closed i.e. mechanically operated thermostatic
controlvalves, must befitted with aby-pass circuit capable
of:-
1. Dissipating a minimum of 1kW (3,400 Btu/h)
2. Maintaining a minimum water flow through the
boiler of 9 litres/min (2 gal/min).
A suggested method of meeting these requirements by
using a bathroom radiator fitted with two lockshield valves
is shown in Figs. 8 & 9.
Diagrammatic layouts of a fully pumped system and a
combinedpumpedcentralheating/gravity hot water system
are shown in Figs. 7 & 8.
Sealed Systems (Fully Pumped)
Installation
The installation must comply with the requirements of BS
6798: 1987 and BS 5449: Pt 1. The British Gas publication
"BritishGasSpecification for DomesticWetCentralHeating
Systems" should also be consulted.
Safety Valve
A non-adjustable spring-loaded safety valve, preset to
operate at 3 bar (45lbf/in²) shall be used. It must comply
with BS 6759: Pt 1. and include a manual testing device. It
shall be positioned in the flow pipe either horizontally or
vertically upwards and close to the boiler. No shut-off
valves are to be placed between the boiler and the safety
valve. The valve should be installed into a discharge pipe
which permits the safe discharge of steam and hot water
such that no hazard to persons or damage to electrical
components is caused.
Pressure Gauge
A pressure gauge incorporating a fill pressure indicator,
covering the range 0 - 4 bar (60 lbf/in²) shall be fitted to the
system. It should be connected to the system, preferably
at the same point as the expansion vessel. Its location
should be visible from the filling point.
Expansion Vessel
A diaphragm type expansion vessel to BS 4814: Pt 1. shall
be fitted close to the inlet side of the pump. The connecting
pipework should not be less than 15mm. Pipework
connecting the expansion vessel should not incorporate
valves of any sort. Methods of supporting the vessel are
supplied by the vessel manufacturer. The nitrogen or air
charge pressure of the expansion vessel shall not be less
than the hydrostatic head, (height of the top point of the
system above the expansion vessel).

Publication No. 5102977
12 Installation Requirements
Cylinder
The hot water cylinder must be an indirect coil type or a
direct cylinder fitted with an immersion calorifier suitable
for operating at a gauge pressure of 0.3 bar (5 lbf/in²) in
excessofsafetyvalvesetting.Singlefeedindirectcylinders
are not suitable for sealed systems.
Method of Make-up
Provision shall be made for replacing water loss from the
system either:-
i) from a make-up vessel or tank mounted in a position
higherthanthe toppointofthesystem, andconnected
through a non-return valve to the system on the
return side of the hot water cylinder or the return side
of all heat emitters.
or
ii) where access to a make-up vessel would be difficult
by using the mains top up method or a remote
automaticpressurisationandmake-upunitasshown
in Fig. 10.
Mains Connection
There shall be no connection to the mains water supply or
to the water storage tank which supplies domestic hot
watereventhrougha non-return valve, without theapproval
of the Local Water Authority.
Filling Point
The system shall be fitted with a filling point at low level
which incorporates a stop valve to BS 1010 and a double
check valve of an accepted type to be fitted in this order
from the system mains, see Fig. 10.
Boiler Heat Exchanger: 6.5 litres
Small Bore Pipework: 1 litre per kW of system
output
Micro Bore Pipework: 7 litres
Steel Panel Radiators: 8 litres per kW of system
output
Low Water Capacity Radiators: 2 litres per kW of system
output
Hot Water Cylinder: 2 litres
If the system is extended, the expansion vessel volume
mayhaveto be increased unless provisionhasbeen made
for extension. Where a vessel of the calculated size is not
available, the next available larger size should be used.
The boiler flow temperature is controlled at approximately
82°C.
Thevesselsize cannowbedeterminedfrom theinformation
in Table 4 where V = System volume in litres.
1.0
1.0
V x 0.087
Vessel Charge Pressure (bar)
Initial System Pressure (bar)
Expansion Vessel Volume (litres)
0.5
1.0
V x 0.11
Table 4.
To size the expansion vessel it is first necessary to
calculate the volume of water in the system in litres. The
following volumes may be used as a conservative guide to
calculating the system volume.
Circulation Pump Selection
The resistance through the heat
exchanger when operating with a water
flowrateproducingan 11°C temperature
riseatmaximumboileroutputareshown
in Table 5. If other controls such as 3
position valves are used in the system,
the resistance through them, quoted in
their manufacturers literature must be
taken into account. The pump may be
fitted on either flow or return. It must be
fitted with two isolating valves which are
positioned as close to the pump as
possible. Closing of any valve must
alwaysleavetheopenventunobstructed.
On fully pumped systems either return
connection may be used.

Publication No. 5102977 13
CON0093B
Installation Requirements
Fig. 8
Fig. 7

Publication No. 5102977
14 Installation Requirements
Fig. 9
Fig.10

Publication No. 5102977 15
2. Installation
2.1 Install the boiler
These instructions assume you have decided
on where the boiler will be located and the type
of flue system to be used.
1. Carefully unpack the boiler. Remove and
place aside the tailpipe/gravity stat kit and
on CFL boilers, the ancillary bag containing
the top and rear blanking plates with seal
and control panel.
2. Do not discard any packaging until all the
items are accounted for.
3. Temporarily position the boiler to ensure
where required, the top cover touches the
wall. This sets the minimum rear clearance
for the pipework. Mark the position on the
floor.
4. Remove the plinth - 2 screws.
5. Remove the front door - 2 screws, unhook
and lift off.
6. Remove the controls panel - open flap,
remove screw, unhook, disconnect the in-
line connector and lift away.
7. Remove the top cover - 2 screws, pull
forward and lift off.
Installation
Fig. 12
2.2 Install the flue
Install the flue type as required.
Conventional Flue:
1. Loosenthe4screwssecuring the flue spigot
to the boiler, line the spigot up with the flue
and fully tighten the screws.
Note: From its fully rearward position the
spigot will move forward 50mm.
CON0021F
Fig. 11

Publication No. 5102977
16 Installation
Fig. 14
Centre of
the Flue
Cut Out Hole
Front Edge
Rear Edge
Top View of the Work top
Minimum
from Wall
Maximum
from Wall
135
Max.
C/L. C/L.
115
85 Minimum
200
200
100
100
200
200
CON0075A
2. Attach the flue to the flue spigot.
This product is fitted with a combustion
productsdischargesafetydevice(TTB)which
must not be taken out of operation at any
time. The component is fitted to ensure that
any blockage or partial blockage of the flue
does not result in combustion products
discharging into the room.
Fitting under a Worktop (CFL Models)
1. Remove the top blanking plate from the
boiler (if already assembled).
2. SeeSection4.9 onpage28of theInstallation
&ServiceInstructions,removetheproducts
dischargesafetydevice(TTB)and carefully
place on top of the appliance.
3. Remove the flue spigot from the appliance
by removing the 4 adjusting screws.
4. Mark the centre of the flue on the work top
and cut a 200 mm square hole from this
centre point. The centre point should be a
minimum of 85 mm from the wall and a
maximum of 135 mm from the wall being
dependent on the boiler position.
5. Place boiler in position under the work top.
6. Re-fit the flue spigot as shown in Fig. 13.
7. Refit the products discharge safety device
(TTB) back onto the flue spigot and secure
with the screw.
8. It is a requirement that after disturbing the
products discharge safety device, a full
operationalcheckshould be madetoensure
correct operation i.e. with the boiler fully
operating, temporarily block the flue. The
safetydischargedeviceshouldoperateand
the boiler go to lockout in less than 2
minutes.
9. Unblock the flue after the test.
Wall
Ceiling
(Combustible
Material)
Flue
Spigot
80
Min.
Plus 50
max
Minimum
25mm
clearance
Conventional
Flue
Top Blanking
Plate
Rear
Blanking
Plate
Flue
Spigot
Air Box
CON0034E
Fig. 13

Publication No. 5102977 17
Fitting the Blanking Plate
1. If the flue is not fitted in the fully forward
position, the rear blanking plate will need to
be cut to size, cut trim to length as required.
See Fig. 15.
• If fitting under a worktop then drill 2 pilot
holesthroughtheholesintherearblanking
plate plate and into the work top. Secure
the plate using 2 woodscrews (not
supplied).
2. Locate the top blanking plate as shown in
Fig. 15.
BalancedFlue:
1. Mark the flue outlet hole position on the wall
as illustrated.
Note: Ensure that the correct allowance is
made for side outlet when the boiler is not
being pushed fully back.
2. Carefully cut hole through wall.
Maximum flue lengths are as follows:
40 - 70 models 3.4 m
80model 2.4 m
90model 1.4 m
100model 1.0 m
These are for rear or side flue applications
see Page 17 Fig. 16.
3. DeterminedimensionX+20 mmSeeFig.13.
4. Extendtelescopicflue to therequiredlength,
minimum 20 mm overlap.
5. Drill through the pilot hole and secure with
a self tapping screw.
6. Wraptapearoundthejoint on the outer duct
tosealtheflue, slide drip ring into positionto
coincide with the air gap in the wall cavity.
7. Slide the flue through the hole until it stops
on the pin.
8. Theboilerissupplied with the flue elbow set
for the rear. For side outlet slacken the
screws, turn the elbow as required and
retightenscrews.
Note:Ensurethatthesealsarestillcorrectly
located.
Air Box
Top Edge of
Work top
Cut
Out
Hole
Top of
Boiler
Work top
CON0076A
Fit Top
Blanking
Plate
Refit Flue
Spigot
Cut to size
(if required) Fit Trim
Screw Rear
Blanking Plate
to work surface
Installation
Fig. 16
CON0077A
180 min
180 min
778
110 Dia.
Hole
31 min
73 min
70 Min.
Fig. 15

Publication No. 5102977
18 Installation
9. Slide the flue back until it engages in the
elbow bayonet connection, twist clockwise
to lock.
10.Drillthroughpilotholeandlockflueinposition
using the self tapping screw provided.
11.Make good the wall around the flue, both
inside and outside.
For optional extras refer to Page 38 & 39. If
aHorizontalExtensionisrequiredthis MUST
becombinedwithaStandardFlueas shown
in the Maximum Flue Length Guide.
If an in-line bend is required in the flue the
following rules apply:-
A 90° in-line bend is equivalent to a 1m
length of flue.
A 135° in-line bend is equivalent to a ½m
length of flue.
The maximum equivalent flue resistance
allowed when using bends is:-
40 - 70 models = 3.4 m.
80 model = 2.4 m.
90 - 100 models - No bends allowed.
Note:Forfluelengthslessthantheminimum
telescopic length, the tubes can be cut to
suit.Ensurethatthe same length isremoved
from the inner and outer tubes to maintain a
minimum 20 mm overlap.
For further information see publication
'CombinationFlues'.
Fig. 17

Publication No. 5102977 19Installation
Fig. 19
2.3 Connect the Gas Supply
1. Ensure that the gas supply is isolated.
2. Disconnectthegascockfromthegasvalve.
3. Connect the gas supply to the gas cock
using a suitable adaptor.
Important:
Do not solder the fitting whilst
assembled to the gas cock.
The pipe diameter required will depend on
the boiler model and the pipe length from
the gas meter. Ensure that the gas supply
pipeisselectedinaccordancewithBS6891
so that an adequate gas supply to the boiler
is provided.
4. Connect the gas cock to the gas valve.
Do not turn the gas supply on at this stage.
2.4 Connect the Water System
When attaching the standard pipe connecting kit to the boiler please note that the seal is made by use of an 'O' ring,
therefore some pipe movement will be evident even though a water tight seal has been achieved. Excessive force is
not necessary and could result in damage to the appliance.
1. Connectsystempipeworktothe boiler, compression fittings should beused.Arrange pipework to ensure correct venting
of pipes and boiler. On gravity systems a tee is required in the flow which must be fitted directly to the connecting pipe
supplied. Note: Drain off taps should be installed at the lowest points in the system.
2. If on a Gravity DHW system position the overheat thermostat as shown.
3. To do this - unscrew the overheat thermostat from the flow pipe and re-attach as shown using the bracket and screw
found in the tail pipe/gravity stat kit.
CON0025B
Gas Pipe
Installed
Gas
Cock
Gas Cock
Rc ½"
½" B.S.P.
Female
Gas
Valve
Connect Gas Pipe
Stage
1
Stage
2
'ON'
'OFF'
Disconnect
Gas Cock
from the
Gas Valve
Return
(Pumped)
Return
(Pumped)
CON0020D
Fig. 18

Publication No. 5102977
20 Installation
Fig. 20
2.5 Connect the Power Supply Cable
1. Cable clamping is provided on the front of
the controls panel. Feed the cables up and
over the back of the chassis, through the
clamp and into the terminal connection.
Note: When connecting the power supply
cable, ensure that the length of the earth
wire is such, that if the power supply cable
pulls out of the cable clamp the live and
neutral wires become taut before the earth
wire.
If fitting the optional integral programmer,
refer to the instructions supplied with it for
wiring details.
For Gravity DHW/Pumped CH Systems,
the pump should be wired externally.
ForFullyPumped Systems, connect pump
to Pump 'L, N, E' on the terminal block.
2. Where no integral programmer is fitted,
connect the wires as follows;
GravityDHW/PumpedCHSystems
a. Fitalinkbetween terminals MAINS 'SwL'
and MAINS 'L'.
b. SwitchedlivefromexternalgravityDHW
control circuit to MAINS 'SwL'.
c. Neutral to MAINS 'N'.
d. Earth to MAINS 'E'.
e. The pump should be wired externally.
Fully Pumped Systems
a. Permanent live to terminal MAINS 'L'
b. Switched live from external controls to
MAINS 'SwL'.
c. Neutral to MAINS 'N'.
d. Earth to MAINS 'E'.
e. Pump to PUMP 'L, N, E'.
Open Vented Fully Pumped Systems
The boiler is fitted as standard with an
overheat thermostat and pump overrun
device which requires a permanent live to
the boiler. This is the recommended
installation method (see above).
However,inreplacementsituationswherea
permanentliveisnot available, it is possible
towiretheboilerwith 3 core cableasfollows,
providing the system has a separate cold