Potterton Puma Flowsure+ Installation and maintenance instructions

Part No. 27/20334 - 01
Puma Flowsure+ - G.C. No. 47 590 18
Installation & Service Instructions
Puma Flowsure+
Wall Mounted, Fanned, Room Sealed,
Storage Combination Boiler
THE GAS SAFETY (INSTALLATION AND USE) REGULATIONS 1994.
‘‘ 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.’’
The polythene bags used for packaging are a potential hazard to babies and young children
and MUST BE DISPOSED OF IMMEDIATELY.
LEAVE THESE INSTRUCTIONS WITH THE USER FOR USE ON FUTURE CALLS
For Use With Natural Gas
(G20) Only At 20mbar
For Use in GB & IE
IMPORTANT
PLEASE READ THIS BOOK
BEFORE INSTALLING,
OPERATING OR SERVICING
THIS APPLIANCE.

2Contents Part No. 27/20334
Contents - Page 2
Technical Data........................................................3
Introduction ............................................................4
1. Installation Requirements.....................................6
1.1 General Information.......................................6
1.2 Location of Boiler...........................................7
1.3 Flue Terminal and Ducting ............................8
1.4 Air Supply......................................................9
1.5 Guide to System Requirements.....................9
1.6 Mains Water Feed C.H..................................10
1.7 Installation to an Existing System..................10
1.8 Hard Water Areas..........................................10
1.9 Pump Performance Curve.............................10
1.10 Domestic Hot Water - 50 Litre Tank..............11
1.11 Electrical Supply............................................13
1.12 Clearance Around the Appliance...................14
2. Installation..............................................................15
2.1 Unpacking......................................................16
2.2 Installation - Boiler.........................................16
2.3 Installation - Storage Tank.............................17
2.4 Gas Connection.............................................18
2.5 D.H.W Supply................................................18
2.6 C.H. Supply ...................................................18
2.7 Pressure Relief Valve....................................19
2.8 Wiring the Appliance......................................19
3. Commissioning......................................................20
3.1 Electrical Installation......................................20
3.2 Gas Installation..............................................20
3.3 Initial Lighting.................................................21
3.4 Gas Pressure Adjustment..............................22
3.5 Products of Combustion Measurement.........23
3.6 D.H.W Flow Rate...........................................24
3.7 Central Heating..............................................24
3.8 Temperature Controls....................................24
3.9 Appliance Protection Devices........................24
3.10 Re-fit Outer Case...........................................25
3.11 Handing Over to the User..............................25
4. Servicing.................................................................26
5. Routine Maintenance.............................................27
5.1 Remove the White Front Case......................27
5.2 Remove Base Panel......................................27
5.3 Remove the Air Box Covers..........................27
5.4 Remove the Fan Assembly........................27
5.5 Remove the Flue Hood..............................27
5.6 Remove the Combust. Cham.
Front Panel................................................27
5.7 To Inspect and Clean the Boiler ................27
5.8 To Remove the Burner ..............................29
5.9 Gas Pressure Adjustment..........................29
5.10 The Central Heating Sealed System.........29
5.11 Other Components ....................................29
6. Component Replacement..................................31
6.1 Central Heating Overheat Thermostat.......32
6.2 Sensor and Ignition Electrode....................32
6.3 Sensor and Ignition Leads.........................32
6.4 Burner........................................................32
6.5 Injectors.....................................................32
6.6 Gas Valve..................................................32
6.7 Modulating Valve.......................................33
6.8 First Solenoid Valve...................................33
6.9 Second Solenoid Valve..............................33
6.10 Case Seal..................................................33
6.11 Central Heating and Boiler Switch.............33
6.12 Electronic Control Boards..........................35
6.13 Air Pressure Switch ...................................36
6.14 Fan.............................................................36
6.15 Fan Seals...................................................36
6.16 Flow Temperature Sensor.........................36
6.17 Pressure Gauge.........................................36
6.18 Pump.........................................................37
6.19 Expansion Vessel C.H...............................37
6.20 Heat Exchanger.........................................38
6.21 Automatic Air Vent.....................................39
6.22 Pressure Relief Valve................................39
6.23 Transformer Assembly...............................40
7. Fault Finding .......................................................41
8. Control Flow Sequence...................................... 42
9. Functional Flow...................................................43
10. Schematic Wiring Diagram................................44
11. Electrical Diagrams ............................................ 45
12. Short List of Spares............................................ 46

Part No. 27/20334 Technical Data 3
Technical Data - Page 3
Boiler Details
Heat Input: kW 30.00 - Max.
Btu/hr 102,350
kW 22.5 - Range Rate
Btu/hr 76,760
kW 14.4 - Min
Btu/hr 49,130
Heat Output: kW 24.00 - Max.
Btu/hr 81,880
kW 17.2 - Range Rate
Btu/hr 58,680
kW 10.4 - Min
Btu/hr 35,480
Gas Rate m³/hr 2.86
ft³/hr 101
Inlet Pressure mbar 20 (18 - 25mbar)
Burner Pressure mbar 15.0 - Max
in/wg 6.0
mbar 8.3 - Range Rate
in/wg 3.3
mbar 3.5 - Min
in/wg 1.4
Classifications I2H, C12 & C32 IP20
Pilot Burner Bray AB 1920
Main Burner Bray AB 24081M
Gas Control Valve: SIT Controls Nova 827 (0.827.127)
Inc. 1st Solenoid Valve (0.007.424)
Inc. 2nd Solenoid Valve (0.007.406)
Inc. Modulator - 28V. DC. (0.007.413)
Burner Injector 3 off
Electrical Supply 230V ~ 50Hz
Fuse Rating External 3A
Packed Weight 58.5kg (129lbs)
Water Content 1.85 litres - C.H.
Connections - Gas
Gas ½" B.S.P.F. Gas Cock
Connections - Water
Inlet DHW 15mm Compression Isolating Valve
Outlet DHW 15mm Copper Pipe
Flow CH 22mm Compression Isolating Valve
Return CH 22mm Compression Isolating Valve
Safety Discharge 15mm Copper Pipe
C.H. Sealed System
Operating Pressure 2.5bar (36.3lb/in²) Max
Operating Pressure 0.5bar (7.25lb/in²) Min
Expansion Vessel 10 litre
(Pre-charge Pressure 1.0bar)
Temperature Rise across
the Boiler 30°C - Max
Central Heating Flow
Temperature 85°C - Max. Load
90°C - Min. Load
Central Heating Return
Temperature 74°C (Nominal)
Storage Tank Details - 50 Litre
Packed Weight 20kg
Full Weight 65kg
Max. Cold Water
Supply Pressure 10 bar
Normal Secondary
Operating Pressure 3.5 bar
Secondary Expansion
Vessel Charge Pressure 3.5 bar
Water Capacity 2.9 litres primary
41.8 litres secondary
T & P Valve 90°C / 7 bar
Pressure Relief Valve 6 bar

4Introduction Part No. 27/20334
Introduction - Page 4
GAS SAFETY (INSTALLATION AND USE)
REGULATIONS 1994.
The appliance must be installed and serviced by a
competent person, in accordance with the above
Regulations.
In the UK 'Corgi' Registered Installers (including the
Regions of British Gas) undertake the 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.
Samples of the Puma Flowsure+ gas boilers have been
examined by Gastec, a Netherlands 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
and are therefore permitted to carry the CE Mark.
The appliance has been tested and approved by the WRc
as meeting the requirements of G3 and L of the Building
regulations and water Bylaws Scheme - Approved
Products.
The Puma Flowsure+ boilers are fully automatic, wall
mounted, fan assisted, room sealed storage combination
boilers, designed to operate on Natural Gas only.
The Puma Flowsure+ adjusts automatically to provide
central heating outputs between 24 kW (81,880 Btu/h) and
10.4 kW (35,480 Btu/h) to suit the system requirements.
Domestic hot water has priority over the central heating
system and is generated within the tank.
The range of horizontal and vertical flue systems with small
terminals simplify siting and installation.
The combination boilers are designed for use with fully
pumped sealed system only.
They are supplied fully tested and assembled with a
circulating pump, diverter valve, pressure gauge, pressure
relief valve, and expansion vessels.
Fig. 1 shows the main components of the boiler assembly.
A central heating switch controls the choice of service
between central heating/hot water and hot water only.
The boiler water flow system is shown in Fig. 2.
With the central heating switch set to 'Off' and the boiler
switch set to 'On', the combination boiler fires only when
hot water is drawn off and occasionally to maintain the
temperature of the stored hot water.
With the central heating switch set to 'Timed' the boiler will
operate the central heating for the time periods set on the
optional internal or externally mounted timeclocks.
If 'Constant' is selected the boiler will operate continuously.
The temperature of the central heating can be changed by
adjusting the knob on the front of the appliance.
The domestic hot water is supplied at a pre-set
temperature determined by the d.h.w mixing valve setting.
If domestic hot water is drawn off while the central heating
is running the combination boiler will automatically transfer
the boiler heat output to the domestic hot water supply.
At the minimum hot water draw-off rate the maximum
temperature is limited to 60°C by the mixing valve in the
tank. This temperature can be changed by adjusting the
mixing valve knob.
The combination boiler has a white front case which can be
removed for servicing.
Data plates are positioned on the front of the air box door
and a boiler serial badge is on the underside of the air box.
A duplicate serial badge is positioned on the underside of
the case base for customer reference.
A data badge is also located on the tank.

Part No. 27/20334 Introduction 5
Introduction - Page 5

6Installation Requirements Part No. 27/20334
1. Installation Requirements - Page 6
1.1 General Information
Prior to installation the boiler should be stored as directed
on the carton and in a dry place. Both the user and the
manufacturer rely heavily on the installer, whose job it is to
install the combination boiler, and connect it to a correctly
designed heating system. Acquaint yourself with the
British Standards concerning installation requirements. If
you need advice on any points, Potterton's Service
Operations will be pleased to help (see back page). It is
recommended that tools suitable for brass fittings are used,
and have a capability to accommodate hexagon sizes up to
50mm.
Codes Of Practice
I.E.E Regulations
Model Water Bye Laws
Building Regulations/Building Standards for Scotland.
Health and Safety Document No.635. (The Electricity at
Work Regulations 1989)
BS. 6891 Installation of low pressure pipes.
BS. 6798 Installation of gas boilers of rated input not
exceeding 60kW.
BS. 5449 Forced circulation hot water C.H. systems.
Including smallbore and microbore domestic
central heating systems.
BS. 5546 Installation of gas hot water supplies for
domestic purposes.
BS. 5440:1 Flues (for gas appliances of rated input not
exceeding 60 kW).
BS. 5440:2 Air supply (for gas appliances of rated input
not exceeding 60 kW).
BG. DM2 Guide for gas installation in timber framed
buildings.
It is important that no external control devices e.g. flue
dampers, economisers etc., be directly connected to this
appliance unless covered by these Installation and Service
instructions or otherwise recommended by Potterton in
writing. If in doubt please enquire.
Any direct connection of a control device not recommended
by Potterton could invalidate the certificate and the normal
appliance warranty and could also infringe the Gas Safety
Regulations.
Manufacturers instructions must not be taken in any way as
over-riding statutory obligations.
Gas Supply
The local Gas Region should be consulted, at the
installation planning stage, in order to establish the
availability of an adequate supply of gas.
An existing service pipe must NOT be used without prior
consultation with the Local Gas Region.
A gas meter can only be connected by the Local Gas
Region, or by a Local Gas Region Contractor.
An existing meter should be checked, preferably by the
Gas Region, to ensure the meter is adequate to deal with
the rate of gas supply required.
Installation pipes should be fitted in accordance with BS
6891.
Pipework from the meter to the combination boiler must be
of an adequate size.
Do NOT use pipes of a smaller size than the combination
boiler inlet gas connection (15mm).
The complete installation must be tested for gas
soundness and purged as described in BS 6891.
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 - Ceramic Fibre. Alumino - Silicone 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. Irritation to respiratory tract.
Precautions - 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
discomfort, follow good hygiene practices, wash hands
before consuming food, drinking or using the toilet.
First Aid - Medical attention must be sought following eye
contact or prolonged reddening of the skin.
Heat Exchanger
Material - Copper with lead/tin coating.
Description - Finned copper tube.
Known Hazards - Inhalation or ingestion of lead dust or
fumes may cause headache and nausea.
Precautions - Unused heat exchangers present minimal
risk to health other than normal hygiene practices would
demand regarding washing before eating etc. Deposits
found on or below a heat exchanger that has been in use
could contain lead oxide. Avoid inhalation by using a
vacuum cleaner in conjunction with other cleaning tools
when servicing the appliance.

Part No. 27/20334 Installation Requirements 7
Installation Requirements Page 7
Fig 2
1.2 Location Of Boiler
In siting the combination boiler, the following limitations
MUST be observed:
a) The position selected for installation should be within
the building, unless otherwise protected by a suitable
enclosure. It must allow adequate space for
installation, servicing and air circulation around the
appliance.
b) This position MUST also allow the chosen flue
termination to be made correctly. The boiler must be
installed on a flat vertical wall which is capable of
supporting the weight of the appliance and any
ancillary equipment.
The appliance may be installed on a combustible wall,
subject to the requirements of the Local Authorities and
Building Regulations.
IMPORTANT NOTICE
If the combination boiler is to be fitted in a timber framed
building it should be fitted in accordance with the British
Gas publication 'Guide for Gas Installations in Timber
Frame Housing'. (Reference DM2).
If in doubt advice must be sought from the Local Gas
Region of British Gas.
The combination boiler may be installed in any room or
internal space, although particular attention is drawn to the
requirements of the current I.E.E. Wiring Regulations, and
in Scotland, the electrical provisions of the Building
Regulations applicable in Scotland, with respect to the
installation of the combination boiler in a room or internal
space containing a bath or shower.
Where a room-sealed appliance is installed in a room
containing a bath or shower, any electrical switch or
appliance control, utilising mains electricity should be so
situated that it cannot be touched by a person using the
bath or shower.
A compartment used to enclose the combination boiler
MUST be designed and constructed specifically for this
purpose. An existing cupboard, or compartment, may be
used provided it is modified accordingly. See Section 1.4
Air Supply.
Where installation will be in an unusual location, special
procedures may be necessary. BS 6798 gives detailed
guidance on this aspect.

8Installation Requirements Part No. 27/20334
Installation Requirements - Page 8
POSITION MIN. DISTANCE mm
ADIRECTLY BELOW AN OPENABLE WINDOW,
AIR VENT, OR ANY OTHER VENTILATION
OPENING 300
BBELOW GUTTER, DRAIN/SOIL PIPE 75
CBELOW EAVES 200
DBELOW A BALCONY/CARPORT ROOF 200
EFROM VERTICAL DRAIN PIPES AND
SOIL PIPES 75
FFROM INTERNAL OR EXTERNAL CORNERS 300
GABOVE ADJACENT GROUND OR BALCONY
LEVEL 300
HFROM A SURFACE FACING THE TERMINAL 600
IFACING TERMINALS 1,200
JFROM OPENING (DOOR/WINDOW) IN
CARPORT INTO DWELLING 1,200
KVERTICALLY FROM A TERMINAL ON THE
SAME WALL 1,500
LHORIZONTALLY FROM A TERMINAL ON
THE SAME WALL 300
MADJACENT TO OPENING 300
NABOVE ROOF LEVEL (TO BASE OF TERMINAL) 300
PFROM ADJACENT WALL TO FLUE 210
QFROM INTERNAL CORNER TO FLUE 230
RBELOW EAVES OR BALCONY 600
SFROM FACING TERMINAL 1,200
1.3 Flue Terminal and Ducting (Fig: 3 - a, b & c)
The standard horizontal flue system (Potterton Part
No.31-19619) is suitable for installations up to 1092mm,
measured from the centre line of the boiler outlet to the
outside face of the wall. The wall liner enclosed will
accommodate thicknesses of 400mm and can be cut to a
minimum length of 76mm.
One metre flue extension kits (Part No. B4286 or 31-19033)
are available to extend horizontal flues to a maximum length of
3078mm.
90° In-line elbow kits (Part No. 31-19034) and 135° In-line
Bend kits (Part No. 31-19035) are also available for more
flexible siting. Horizontal flues can be set at 45° angles to the
combination boiler, through 360°, to the miniature terminal on
the outside of the building. The siting positions for horizontal
flue terminals are shown in Figs. 3. - a) & b).
A Concentric Vertical flue system is available (Part No.31-
19036) which when used in conjunction with One metre flue
extension kits (Part No. 31-19033) is suitable flue heights up
to 3 metres to terminate through a roof.
A Twin tube Vertical flue system is also available for flue
heights up to 8025 mm (Part No. 31-19037) when used in
conjunction with one metre twin tube extension kits (Part
No. 31-19038).
A Pitched Roof Flashing kit (Part No. 31/19041) and Flat
Roof Flashing kit (Part No. 31/19040) are available for use
with the vertical flue systems.
135° Off-set kits are available for both types (Part No.31-
19035 concentric) and (Part No.31-19039 twin tube). The
siting of the flue terminal through a roof is shown in Fig 3. - c).
Only the above flue systems should be used with Puma
Flowsure+ storage combination boilers.
If 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 (Part No. 929729).
Note: Where a flue terminal is installed less than 1 metre from
a plastic, or painted gutter, or 500mm 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 combustion are found
to be re-entering any building, the appliance MUST be turned
OFF IMMEDIATELY.
1.4 Air Supply (See Table 2)
Detailed recommendations for air supply are given in BS
5440:2. The following notes are intended for general guidance:
It is not necessary to have a purpose provided air vent in the
room or internal space in which the combination boiler is
installed. If the combination boiler is to be installed in a
cupboard or compartment, permanent air vents are required
(for cooling purposes) in the cupboard/compartment, at both
high and low levels. The air vents must either communicate
with a room/or be direct to outside air.

Part No. 27/20334 Installation Requirements 9
Installation Requirements - Page 9
Position of
Air Vent Air from Room/ Internal Space Air Direct from Outside
High
Level 264 cm2 40 in2132 cm2 20 in2
Low
Level 264 cm2 40 in2132 cm2 20 in2
Table 2. Air Supply
1.5 Guide to System Requirements (Figs. 4 & 6)
These combination boilers are specifically designed for sealed
systems only. Therefore the central heating system should be
in accordance with the relevant recommendations given in BS
6798 and also, smallbore and microbore systems BS 5449
Part 1.
For correct operation the boilers require a by-pass.
A valved by-pass should be fitted and the flow reduced to
balance the system correctly. The length of the by-pass
pipework is not important.
Note: If the by-pass flow is reduced too much this will cause
the appliances to overheat and go to lockout.
The installation should be designed to work with flow
temperatures of up to 90° C. All components of the system
must be suitable for a maximum pressure of 3 bar (45 psi) and
a temperature of 110° C.
The following components are incorporated within the boiler.
a) Circulating pump.
b) Diverter valve.
c) Pressure Relief valve with a non-adjustable pre-set lift
pressure of 3 bar (45 psi).
d) Pressure gauge covering the range 0-4 bar (0-60 psi).
e) 10 litre expansion vessel with initial charge pressure of
1.0 bar (14 psi).
The domestic hot water system must be in accordance with
the relevant recommendations of BS 5546. Copper tubing to
BS 2871:1 is recommended for water carrying pipework and
MUST be used for pipework carrying potable water. All
capillary joints in the D.H.W pipework must be joined with a
lead free solder.
Ancillary pipework, not forming part of the useful heating
surface, should be lagged to prevent heat loss and any
possible freezing, particularly where pipes run through roof
spaces and ventilated under-floor spaces.
If the capacity of the central heating system should exceed
100 litres, an additional vessel should be installed on the
return to the combination boiler from the heating system (Fig.
4). Guidance on vessel sizing is given in Table 3.
To allow the maximum central heating expansion capacity in
the boiler the pre-charge pressure in the central heating
expansion vessel must be marginally greater than the initial
(cold) system pressure at the appliance (as shown on the
appliance pressure gauge).
Draining taps should be at least 1/2 in BSP nominal size and
be in accordance with BS 2879.
Safety Valve Setting (bar) 3.0
Initial System Pressure (bar) 1.0 1.5
Total Water Content of System VESSEL VOLUME (L)
litres
25
50
75
100
125
150
175
200
225
250
275
300
325
350
375
400
425
450
475
500
litres
2.7
5.4
8.2
10.9
13.6
16.3
19.1
21.8
24.5
27.2
30.0
32.7
35.7
38.1
40.9
43.6
46.3
49.0
51.8
54.5
litres
3.9
7.8
11.7
15.6
19.5
23.4
27.3
31.2
35.1
39.0
42.9
46.8
50.7
54.6
58.5
62.4
66.3
70.2
74.1
78.0
For system volumes other than
those given above, multiply the
system volume by the factor across 0.109 0.156
Table 3. Expansion Vessel Requirements
Deduct from the value given in the table the 10 litre expansion vessel supplied.
External Controls
To obtain economical use of the appliance it is advisable to fit
external controls. The controls can take the form of:-
a) Time clock (two internal options are available
Part No. 31-19053 - Electro-mechanical)
Part No. 31-19054 - Electronic).
b) Room thermostat
c) Thermostatic radiator valves (TRV's)
d) Zone valves
A combination of these controls will produce economical and
effective use of the heat generated by the boiler. It is advisable
to control the temperature of the main living area with a room
thermostat and other areas by TRV's.

10 Installation Requirements Part No. 27/20334
Installation Requirements - Page 10
Frost Protection
The tank of hot water will provide frost protection. This is
purely for the protection of the appliance. If any other part of
the central heating system requires frost protection, an
external frost thermostat must be fitted in the usual manner,
refer to Fig. 9 for wiring.
1.6 Mains Water Feed: Central Heating
A connection must be incorporated into the central heating
system to facilitate filling. There must be no direct connection
to the mains water supply, even through a non-return valve,
without the approval of the Local Water Authority.
PERMISSIBLE METHODS OF FILLING
Note: The Puma combination boiler range is fitted with a
diverter valve design which has a manual operation lever to
aid filling. To ease filling of the pump manifold an air bleed
valve is fitted to the diverter and must be opened during filling
until water flows out. The valve should then be closed.
See Fig.13.
(1) DIRECT METHOD (Fig. 5)
A detachable flexible hose is connected to a stop valve fitted
to an outlet on the service main. The other end of the hose is
connected to a second stop valve and a double check valve.
The double check valve is fitted to an inlet connection on the
central heating return pipe under the appliance. The hose
should be disconnected after filling. Where the mains pressure
is excessive a pressure reducing
valve shall be used to make filling easier. The following fittings
shall form a permanent part of the system and shall be fitted in
the order stated.
a) A stop valve complying with the requirements of BS
1010 Part 2, (the temporary hose from the draw off tap
shall be connected to this fitting).
b) Double check valve of an accepted type.
(2) BOOSTER PUMP METHOD
The system may be filled through a self contained unit
comprising a cistern, pressure booster pump and if
necessary, an automatic pressure-reducing valve or flow
restrictor.
The pressure booster pump must be capable of pressurising
the system to a minimum of 1.0 bar (14 p.s.i.) measured at the
appliance.
The cistern should be supplied through a temporary
connection from a service pipe or cold water distributing pipe.
The unit may remain permanently connected to the heating
system to provide limited water make-up.
Provisions for make up water
Provision should be made for replacing water loss from the
system by re-pressurisation of the system. See section on
Permissible Methods of Filling.
Reference should be made to British Gas Publications
"Material and Installation Specifications for Domestic Central
Heating and Hot Water".
1.7 Installation to an Existing Central
Heating System
The boilers are designed to operate on a sealed system only,
therefore if the existing system is of the open type it will have
to be modified to comply with BS 6798.
Before installing a new combination boiler to an existing
system flush out the old system with a recommended
descaling/flushing agent at least twice.
Also check pipework and renew any corroded pipework or
fittings. Valve glands must be re-packed or replaced wherever
necessary and any defective controls replaced.
1.8 Hard Water Areas
If the area of installation is recognised as a hard water area,
(above 200 p.p.m.) it is essential that a suitable water
treatment device of an electronic, magnetic or galvanic type be
installed in the mains water supply.
To assess water hardness, immerse the test strip supplied, for
about one second in a water sample (NOT IN RUNNING
WATER) so as to moisten all the zones.
Inspect the strip after 1-2 minutes, check the zones, if two or
more zones have changed colour the hardness of the water is
above 200 p.p.m. and a water treatment device will be
required.
1.9 Pump Performance Curve
The circulating pump fitted within the appliance should be
capable of satisfying most system requirements. Fig. 6
indicates the amount of pump head available for the system.
The boiler resistance is already taken into account in this
curve.

Part No. 27/20334 Installation Requirements 11
Installation Requirements - Page 11
HOW TO USE FIG. 6.
Starting with the required SYSTEM HEATING LOAD, draw a
vertical line downwards so that it intersects the chosen
SYSTEM DESIGN TEMPERATURE DROP line, normally this
would be 11°C (20°F) although up to 17°C (30°F) can be used
without increasing radiator sizes. From this intersection point
draw a horizontal line so that it intersects the PUMP CURVE.
From this intersection draw a vertical line upwards.
The AVAILABLE PUMP HEAD can now be read from the
horizontal scale, and the corresponding FLOW RATE from the
vertical scale in the centre of the chart.
The system must be designed so that its hydraulic resistance
does not exceed the available head unless an additional
circulating pump is fitted. More available head can be
achieved by choosing a greater temperature difference.
If the designed flow rate through the boiler is less than 11.5
l/min, the boiler could be noisy and ultimately overheat. See
note on system by-pass in Section 1.5.
Central Heating Range Rate.
For most installations the boiler will automatically adjust the
central heating output to match your heating system
requirement.
Systems which have very low water content and a low heating
requirement may benefit by reducing the maximum boiler
output. This is achieved by rotation of the range rate
adjuster, located on the electronic modulation control board
(see Fig. 26).
The boiler central heating output can be adjusted between the
maximum and minimum values stated on the data badge.
Operation of this adjuster will not affect the maximum boiler
output when domestic hot water is being drawn off.
1.10 Domestic Hot Water - 50 Litre Tank
The 50 litre tank is a secondary store which is designed to be
kept heated to meet instantaneous hot water demands that
require intermittently higher flow rates.
At a flow rate of approximately 12 litres/min, hot water will be
delivered for around 4 minutes at a 50°C rise reducing
thereafter. The tank will fully recover after a few minutes to
again deliver 12 litres/min at a 50°C rise.
Domestic hot water always takes priority over central heating.
If domestic hot water is drawn off while the central heating is
operating the boiler will automatically transfer the boiler output
to the domestic hot water supply.
A secondary water expansion vessel is supplied with the tank
and must be connected to the appropriate tapping on the
controls assembly.

12 Installation Requirements Part No. 27/20334
Installation Requirements - Page 12
IMPORTANT
No Valves should be fitted between the expansion vessel and the storage cylinder.
DHW Store Temperature
Water is stored in the tank at approximately 73°C. To ensure a safe delivery temperature a thermostatic mixing
valve is fitted in the hot water outlet and should be adjusted to produce a hot water delivery temperature of
60°C.

Part No. 27/20334 Installation Requirements 13
Installation Requirements - Page 13
1.11 Electrical Supply
(See Fig. 8 & 9)
Wiring external to the appliance MUST be in accordance with the current I.E.E. Regulations for Electrical Installations, and any
Local Regulations which apply. The combination boiler is supplied for 230 Volts ~ 50 Hz, Single Phase. To protect the
appliance it is essential that the electrical supply is fused at 3 A rating.
THIS APPLIANCE MUST BE EARTHED The method of connection to the mains electricity supply must provide means of
completely isolating the electrical supply to the combination boiler and its ancillary controls. The appliance is designed to be the
wiring centre for the installation, therefore no additional live supplies are required from either timers or room thermostats.
Isolation is preferably by the use of a fused three-pin plug and unswitched shuttered socket-outlet, both complying with the
requirements of BS 1363. (See Fig. 8), OR a 3 A fused double-pole switch, having a 3mm contact separation on both poles can
be used. See Fig. 9. It is important that the point of connection to the mains should be readily accessible and adjacent to the
combination boiler.

14 Installation Requirements Part No. 27/20334
Installation Requirements - Page 14 1.12 Clearances around the Appliance.
(See Fig.11)
Side Clearance:
The position selected for the complete appliance must
provide the following minimum clearance which is
necessary for operation and servicing, 25mm each side of
the unit (left hand side clearance has been incorporated
into template).
Top Clearance:
The top clearance should be a minimum of 160mm, but
300mm is preferred to allow removal of the central heating
expansion vessel, without removing the appliance from the
wall, if replacement is required.
Bottom Clearance:
A bottom clearance of 220mm is required between the
appliance and any surface.
Frontal Clearance:
A minimum of 500mm is required in front of the appliance
for access during servicing, the front clearance can be
reduced providing the door/cover can be removed to
expose the entire case front.

Part No. 27/20334 Installation 15
2. Installation - Page 15
It is MOST IMPORTANT that the appliance is installed in a
VERTICAL POSITION, with the flue system passing
through the wall or ceiling in a Horizontal or Vertical
plane. A minor deviation from the horizontal is acceptable,
provided that this results in a downward slope of the flue
system away from the combination boiler.
2.1 Unpacking
The appliance will arrive on site in three separate
cardboard cartons. Unpack the cartons and check the
contents against the contents lists.
(1) The Boiler
(2) The Flue System.
There is a range of horizontal and vertical flue
systems and optional packs (i.e. extensions / in-
line bends etc.) to suit your requirements which
are supplied separately from the boiler and include
Installation Instructions - See Page 8.
(3) The Tank
2.2 Installation - Boiler
Caution
Some residual water may still be in the
heat exchanger and pipework.
a) Remove the white front case as follows; undo the two
securing screws at the base of the panel, pull the base
of the panel forward approx. 50mm and lift off the
supporting top hooks. (See Fig. 13)
b) Remove the base cover by removing the two fixing
screws and push the cover towards the rear to release
c) Each side panel can now be individually removed by
removing the two front fixing screws, loosening the
lower rear fixing screw and sliding the panel upwards
to unhook from the upper rear fixing. Place each panel
and screws safely to one side. The lower rear fixing
screw from the right hand side will have to be removed
completely before the side panel can be removed.
d) Position the appliance onto its side and remove the
four screws retaining the lowest rear cross brace. This
brace is for transit purposes only and should be
discarded. Remove all plastic plugs from the pipes.
e) Connections: All connections for the boiler & tank are
supplied on the Fittings Card or in the box containing
the water inlet controls assembly. Remove the fittings
for the boiler and assemble to the appliance. See Fig.
12.
Note: When fitted, the Red levered central heating tail
(C.H.flow) should be to the left of the Blue.
f) Tape the wall fixing template to the wall in the selected
appliance position. Allow an extra 475mm from the
right hand edge of the template for the tank (including
clearances).

16 Installation Part No. 27/20334
Installation - Page 16 g) Mark out the position of the flue outlet and the three
boiler mounting holes.
h) Offer the mounting bracket assembly up to the
template and mark two hole positions for the tank
bracket. Remove the assembly and put to one side.
j) At this point follow the Installation Instructions
supplied with the Flue System for the installation of
the flue only, then proceed as follows:-
k) Drill the five previously marked boiler mounting holes
using a 7mm diameter drill to a depth of 50mm. Insert
the plastic wall plugs provided on the boiler Fittings
Card.
l) Attach both the boiler and tank mounting brackets to
the wall using screws from the Fittings Card. The tank
bracket is the one with the two clips over the holes on
the right hand side.
m) Lift the boiler (with the white casing front, base and
side panels removed) into position using a substantial
part of the boiler chassis.
WARNING: DO NOT lift the boiler by the control panel or
other unsubstantial structure as this may result in damage
to the appliance. DO NOT pivot the appliance onto its base
as damage may occur to the underside.
n) Align the boiler with the bottom fixing hole and secure
using a screw from the Fittings Card.
2.3 Installation - Storage Tank
a) Connect the water controls inlet assembly to the base
of the tank. See Fig. 15.
b) Connect the domestic service cock from the Fittings
Card to the cold water inlet (pressure reducing valve)
on the tank.
c) Hang the tank mounting frame over the mounting
bracket and position centrally. If required, additional
fixing holes are provided in the tank mounting frame
and an additional four plugs and screws are supplied
in the fittings pack.
d) Position the expansion vessel as shown and connect
the flexible tube.
e) Put the expansion vessel in place and attach the
expansion tank support bracket to the tank mounting
frame using two screws from the Fittings Card.
f) Hang the storage tank onto the tank mounting frame.
g) Connect the expansion vessel flexible tube to the
storage tank.
h) Attach a ¾ to 22mm compression fitting to the tundish
and run a relief pipe down the back of the mounting

Part No. 27/20334 Installation 17
Installation - Page 17
frame as shown. See Fig. 15.
j) Connect the tundish assembly to the temperature &
pressure valve as shown in Fig. 15. The tundish must
be left visible to the consumer once installed and must
not come into contact with any electrical components.
Connect the pipe supplied to the temperature &
pressure relief valve and the tundish.
k) Remove the two top securing screws and lower the
control box assembly. Fit the flexible hoses from the
boiler to the tank (ensure that the fibre washers
supplied on the Fittings Pack are used), run the hoses
above the pressure gauge and make them as smooth
as possible.
Remove the blanking plate from the diverter valve
outlet, retain the 'O' ring.
Remove the blanking plug from the pump inlet
manifold, discard the fibre washer.
Fit the flow pipe assembly to the diverter valve outlet
using the retained 'O' ring.
Fit the return pipe assembly to the pump inlet manifold.
Use a new fibre washer from the fittings card.
l) Take the side casing bracket assembly from the
storage kit and fit the thermostat using the two M4
screws provided in the Fittings Pack. Secure the
bracket assembly in place using the two self tapping
screws (from the boiler side panel) for the upright
portion. Remove the two M5 screws from the Fittings
Pack and secure the casing bracket to the L-shaped
bracket on the lower right hand side of the boiler.
See Fig. 23.
2.4 Gas Connection
A minimum gas pressure of 20 mbar (8" w.g.) must be
available at the combination boiler inlet at full flow rate,
(see Technical Data).
Install a gas supply pipe not less than 15mm diameter
copper to the combination boiler and connect to the gas
service cock.
2.5 D.H.W. Supply
a) Flush out all foreign matter from the supply pipe before
connecting to the appliance.
b) Connect the cold water supply to the 15mm isolating
cock.
Connect the hot water outlet pipe using a 15mm
compression fitting.
Note: The Cold Water Supply Isolating Cock
incorporates an automatic flow limiting device.

18 Installation Part No. 27/20334
Installation - Page 18
Showers: If a shower control is to be supplied from the
Combination unit it should be of the type which
incorporates a pressure balancing valve (e.g. MIRA 415
EQUAMATIC).
If the shower control is existing and is of a mechanical
type, it may be necessary to fit a drop tight pressure
reducing valve to the mains supply. Refer to the Shower
Manufacturers instructions.
Note: Showers with a loose flexible hose may require the
fitting of a double check valve, to comply with water Bye-
law 17.
2.6 C.H. Water Connections
a) Before any central heating connections are made to the
combination boiler, all system valves should be opened
and the system thoroughly flushed out with cold water.
b) Connect the central heating return pipe to the isolating
cock identified by a Blue lever. (right hand of the two
pipes)
c) Connect the central heating flow pipe to the isolating cock
identified by a Red lever. (left hand of the two pipes).
2.7 Pressure Relief Valves
The pressure relief valve on the boiler is pre-set at 3 bar.
The pressure relief valve on the tank controls is pre-set at 6
bar.
IT MUST NOT DISCHARGE ABOVE AN
ENTRANCE, OR WINDOW, OR ANY TYPE
OF PUBLIC ACCESS.
THE INSTALLER MUST CONSIDER THAT
THE OVERFLOW COULD DISCHARGE
BOILING WATER.
Sizing of Copper Discharge Pipe
Min. size of
discharge
pipe (D1)
15mm
Min. size of
discharge
pipe (D2)
from tundish
22mm
28mm
35mm
Max. resistance
allowed, expressed
as a length of
straight pipe
no elbows or bends
up to 9m
up to 18m
up to 27m
Resistance
created
by each elbow
or bend
0.8m
1.0m
1.4m
Install a pressure relief valve discharge pipe to the boiler
and tank valves, not less than 15 mm diameter and
connect to the pressure relief outlet connection using a
15mm Compression fitting.
The pipe run should be as short as possible, run
continuously downwards and discharge to the outside of
the building, where possible over a drain.
The pipe end should be directed towards the wall.
(see Fig. 18) The discharge point must be such that it will
not be hazardous to occupants or cause damage to
external electrical components or wiring.

Part No. 27/20334 Installation 19
Installation - Page 19
2.8 Wiring the Appliance
The internal wiring of the appliance is shown in Figs. 36 & 37.
The wiring diagram is also on the inside of the front casing
panel.
a) Undo the two retaining screws securing the controls
panel and allow the panel to swing down.
b) Using PVC insulated cable of not less than 0.75 mm²
(24/0.2mm to BS 6500 Table 16) thread the cable
through the wiring clamps and into the electronics
enclosure. Pull up the controls box and re-fit the two
screws, remove the other two screws and allow the
door of the control box to open. Wire up the panel
referring to the termination label - See Fig. 18.
Note: Ensure that all cables pass through the wiring
panel bush/s and are securely fixed by the cable
clamps.
If a room thermostat is to be fitted, remove the White
link wire between terminals 3 and 4 and discard prior
to wiring in the thermostat. If no room thermostat is to
be fitted retain link wire.
If a programmable room thermostat is to be used it
must be fitted in place of the external timer and the link
between 3 & 4 retained.
If the installation does not have an internal or external
timer, the central heating switch on the front of the
appliance must be set to Constant during periods when
central heating is required.
If using an internal timer, connect the timer's lead to
PL11 on the modulation control board. (see Fig. 28)
If an external frost thermostat is required it should be
connected to terminals 3 and 8. For the frost
thermostat to function the boiler switch must be set to
'On'.
c) Connect the thermostat harness to terminals 1 and 3 of
the thermostat. Spread heat sink compound onto the
thermostat sensing bulb and insert it into the bottom of
the tank.
d) Ensure the link terminal is connected to the wiring
harness. This will ensure that the boiler can be
commissioned in CH mode. (The boiler should have
been despatched from the factory with the link terminal
in place).
Note: The electrical mains supply must be fused at 3
A, and the connection must be made to the wiring
panel in such a way that should the lead disengage
from the cable clamp, the current carrying conductors
become taut before the earth conductor.

20 Commissioning Part No. 27/20334
3. Commissioning - Page 20
The Puma Flowsure+ storage combination boiler has been
through a rigorous test procedure after manufacture and
should not require any further adjustment. If in the unlikely
event of the appliance not operating correctly please turn to
the Control Flow, Functional Flow and Fault Finding charts
that start on Page 41.
3.1 Electrical Installation
Conduct a preliminary electrical test by checking: for short
circuits, fuse failure, incorrect polarity, earth continuity and
resistance to earth. If a fault has occurred on the appliance,
the fault finding procedure should be followed. See Page
41.
3.2 Gas Installation
The whole of the gas installation including the meter,
should be inspected and tested for soundness and purged
in accordance with the recommendations of BS 6891.
Purging air from the gas line may be carried out by
loosening the union on the gas service cock and purging.
Re-tighten the union when completed and check for gas
soundness.
N.B. Open all doors and windows, extinguish naked lights
and DO NOT SMOKE when carrying out the gas
soundness tests and purging.