Potterton Puma 100 Installation and maintenance instructions

Part No. 27/19093 - 03
Puma 100 - G.C. No. 47 590 12
Puma 100e - G.C. No. 47 590 13
Installation & Service Instructions
Puma 100 & 100e
Wall Mounted, Fanned, Room Sealed Combination Boiler
THE GAS SAFETY (INSTALLATION AND USE) REGULATIONS 1994 (AS AMENDED).
‘‘ 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 these instructions and the rules in force in the country of destination.
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.

Contents
Technical Data............................................................3
Introduction................................................................4
Optional Extras ..........................................................5
1. Installation Requirements.........................................8
1.1 General Information...........................................8
1.2 Location of Boiler...............................................7
1.3 Flue Terminal and Ducting...............................10
1.4 Air Supply ........................................................10
1.5 Guide to System Requirements.......................11
1.6 Mains Water Feed C.H....................................12
1.7 Installation to an Existing System....................12
1.8 Hard Water Areas............................................12
1.9 Pump Performance Curve...............................13
1.10 Electrical Supply..............................................14
1.11 Clearance Around the Appliance.....................15
2. Boiler Installation.....................................................16
2.1 Unpacking........................................................16
2.2 Gas Connection...............................................17
2.3 D.H.W Supply..................................................17
2.4 C.H. Supply......................................................17
2.5 Pressure Relief Valve......................................18
2.6 Wiring the Appliance........................................18
3. Commissioning........................................................19
3.1 Electrical Installation........................................19
3.2 Gas Installation................................................19
3.3 Initial Lighting...................................................20
3.4 Gas Pressure Adjustment................................21
3.5 Products of Combustion Measurement ...........22
3.6 D.H.W Flow Rate.............................................23
3.7 Central Heating................................................23
3.8 Temperature Controls......................................23
3.9 Appliance Protection Devices..........................23
3.10 Re-fit Outer Case.............................................24
3.11 Handing Over to the User................................24
4. Servicing...................................................................24
5. Routine Maintenance...............................................26
5.1 Remove the White Front Case ........................26
5.2 Remove Base Panel........................................26
5.3 Remove the Air Box Covers ............................26
5.4 Remove the Fan Assembly..............................26
5.5 Remove the Flue Hood ...................................26
5.6 Remove the Combust. Cham. Front Panel .....26
5.7 To Inspect and Clean the Boiler......................26
5.8 To Remove the Burner....................................28
5.9 Gas Pressure Adjustment ...............................28
5.10 The Central Heating Sealed System...............28
5.11 Other Components..........................................28
6. Component Replacement .......................................30
6.1 Central Heating Overheat Thermostat ............31
6.2 Dom. H/Water Limit & Frost Thermostat.........31
6.3 Sensor and Ignition Electrode.........................31
6.4 Sensor and Ignition Leads...............................31
6.5 Spark Ignition Lead .........................................31
6.6 Thermocouple .................................................31
6.7 Burner..............................................................32
6.8 Injectors...........................................................32
6.9 Gas Valve........................................................32
6.10 Modulating Valve.............................................32
6.11 First Solenoid Valve ........................................32
6.12 Second Solenoid Valve...................................32
6.13 Case Seal........................................................32
6.14 Central Heating and Boiler Switch...................35
6.15 Electronic Control Boards................................35
6.16 Air Pressure Switch.........................................36
6.17 Fan..................................................................36
6.18 Fan Seals........................................................36
6.19 Temperature Sensor D.H.W and C.H..............36
6.20 Pressure Gauge..............................................36
6.21 Water Flow Switch D.H.W...............................37
6.22 Microswitch (D.H.W Flow Switch) ...................37
6.23 Pump...............................................................37
6.24 Diverter Valve..................................................38
6.25 Expansion Vessel D.H.W................................39
6.26 Expansion Vessel C.H.....................................39
6.27 Heat Exchanger...............................................40
6.28 Automatic Air Vent...........................................40
6.29 Pressure Relief Valve......................................40
6.30 Water Pressure Switch....................................41
6.31 Transformer Assembly....................................41
6.32 Sight Glass with Securing Frame....................41
7. Schematic Diagrams - Permanent Pilot.............42/45
8. Schematic Diagrams - Electronic.......................46/49
9. Short List of Spares.............................................50/51
GAS SAFETY (INSTALLATION AND USE) REGULATIONS 1994. (As Amended)
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.

Technical Data - Page 3
Heat Input: Max. 36.0kW (122,870Btu/h)
Range Rate (C.H. Only) 20.2kW (69,050Btu/h)
Min. 15.5kW (52,880Btu/h)
Heat Output: Max. 29.0kW (98,980Btu/h)
Range Rate (C.H. Only) 15.5kW (52,880Btu/h)
Min. 11.5kW (39,235Btu/h)
Gas Rate Full 3.43m³/hr 121ft³/hr
Inlet Pressure 20mbar (18 - 25mbar)
Burner Pressure
Max. (Max. Setting on Gas Valve) 14.3mbar (5.7" w.g.)
Range Rate (C.H. Only) 4.8mbar (1.9" w.g.)
Minimum (Electronically Set) 2.8mbar (1.1" w.g.)
Classifications I2H, C12 & C32,
IP20
Pilot Burner Polidoro N525F/27.2
Main Burner Polidoro 401.0192.00 (16 blade)
Gas Control Valve: SIT Controls (100) Nova 825 (0.825.013)
Inc. 2nd Solenoid Valve (0.007.406)
Inc. Modulator - 28V. DC. (0.007.413)
SIT Controls (100e) 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 16 off (1.17mm dia)
Electrical Supply 230V ~ 50Hz
Fuse Rating - External 3A
Packed Weight 62.5kg (137lbs)
Water Content C.H. 1.9 litres
Gas Supply Connection 1/2" B.S.P.F. Gas Cock
Inlet Connection D.H.W 15mm Compression Isolating Valve
Outlet Connection D.H.W 15mm Copper Pipe
Flow Connection C.H. 22mm Compression Isolating Valve
Return Connection C.H. 22mm Compression Isolating Valve
Safety Discharge Pipe 15mm Copper Pipe
C.H. Sealed System
Maximum Operating Pressure 2.5bar 36.3lb/in²
Minimum Operating Pressure 0.5bar 7.25lb/in²
10 Litre Expansion Vessel. Pre-charge Pressure 1.0bar 14.5lb/in²
Maximum Temperature Rise across the Boiler 30°C
Central Heating Flow Temperature Max. Load 79°C
Min. Load 85°C
Central Heating Return Temperature 68°C (Nominal)
D.H.W Flow Rate 35°C Rise 11.9litres/minute 2.62gals/min
D.H.W Flow Rate 45°C Rise 9.2litres/minute 2.03gals/min
D.H.W Temperature: Max. 65°C
Min. 45°C
D.H.W Max. Pressure 10.0bar 145.0lb/in²
D.H.W Min. Operating Pressure (Dynamic) 1.0bar 14.5lb/in²
D.H.W Expansion Vessel. Pre-charge Pressure 3.5bar 50.8lb/in²

Introduction - Page 4
Samples of the Puma combination boiler have been examined
by Gastec, a Netherlands Notified Body. The range is certified
to comply with the essential requirements of the Efficiency
Directive 92/42/EEC, 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 Potterton Puma range of boilers are fully automatic, wall
mounted, fan assisted, room sealed combination boilers,
designed to operate on Natural Gas only. The range of consists
of permanent pilot and electronic versions in both 24 kW and 29
kW (100,000Btu/h) outputs.
The 100 and 100e models adjust automatically to provide
central heating outputs between 29 kW (98,980 Btu/h) and 11.5
kW (39,235 Btu/h) to suit the system requirements.
Domestic hot water has priority over the central heating system
and is generated instantaneously within the appliance.
The combination boilers are designed for use with fully pumped
sealed system only. This has the advantage that header tanks
and hot water storage cylinders are not required.
The range of horizontal and vertical flue systems with small
terminals simplify siting and installation.
They are supplied fully tested and assembled with a circulating
pump, diverter valve, pressure gauge, pressure relief valve, and
expansion vessels.
The appliances have two completely separate heating systems
embedded into a copper heat exchanger. Both systems are
completely independent.
A central heating switch controls the choice of service between
central heating and hot water only. The boiler water flow system
is shown in Fig. 5.
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.
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 central heating is supplied at a pre-set temperature
determined by the central heating thermostat 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 65°C by the modulating gas control.
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.

Optional Extras - Page 5

Optional Extras - Page 6
Installation instructions included as necessary with each kit.

Optional Extras - -Page 7
Installation instructions included as necessary with each kit.

1. Installation Requirements - Page 8
1.1 General Information
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.

Installation Requirements - Page 9
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.

Installation Requirements - Page 10
POSITION MIN. DISTANCE mm
A DIRECTLY BELOW AN OPENABLE
WINDOW, AIR VENT, OR ANY OTHER
VENTILATION OPENING 300
B BELOW GUTTER, DRAIN/SOIL PIPE 75
C BELOW EAVES 200
D BELOW A BALCONY/CARPORT ROOF 200
E FROM VERTICAL DRAIN PIPES AND
SOIL PIPES 75
F FROM INTERNAL OR EXTERNAL CORNERS 25
GABOVE ADJACENT GROUND OR BALCONY
LEVEL 300
H FROM A SURFACE FACING THE TERMINAL 600
I FACING TERMINALS 1,200
J FROM OPENING (DOOR/WINDOW) IN
CARPORT INTO DWELLING 1,200
K VERTICALLY FROM A TERMINAL ON THE
SAME WALL 1,500
L HORIZONTALLY FROM A TERMINAL ON
THE SAME WALL 300
M ADJACENT TO OPENING 300
N ABOVE ROOF LEVEL (TO BASE OF TERMINAL) 300
P FROM ADJACENT WALL TO FLUE 210
Q FROM INTERNAL CORNER TO FLUE 230
R BELOW EAVES OR BALCONY 600
S FROM FACING TERMINAL 1,200
1.3 Flue Terminal and Ducting (Fig: 6 - a, b & c)
The standard horizontal flue system 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 are available to extend
horizontal flues to a maximum length of 3078mm.
90° In-line elbow kits and 135° In-line Bend kits 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. 6. -
a) & b).
A Concentric Vertical flue system is available which when
used in conjunction with One metre flue extension kits 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 8025mm when used in conjunction with one
metre twin tube extension kits.
A Pitched Roof Flashing kit and Flat Roof Flashing kit are
available for use with the vertical flue systems.
135° Off-set kits are available for both concentric and twin
tube. The siting of the flue terminal through a roof is shown
in Fig 6. - c).
Only the above flue systems should be used with Puma
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.
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.

Installation Requirements - Page 11
Table 2. Air Supply
1.5 Guide to System Requirements (Figs. 7 & 9)
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
appliance.
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).
f) Domestic Hot Water flow switch.
*The pump supplied is sufficiently powerful for
heating requirements upto 24kW providing the
designed temperature drop across the heating
system is above 17°C (see pump performance
curve).
The central heating output from the boiler can easily be
downrated if a lower temperature drop across the system is
prefered.
If the central heating system requires an increased pump
head a second circulating pump should be installed. The
pump must be sited on the return to the boiler and
electrically connected using a proprietry relay i.e. Drayton
RB1 - see Section 2.6.
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. 7). 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.
Table 3. Expansion Vessel Requirements
Deduct from the value given in the table the
10 litre expansion vessel supplied.

Installation Requirements - Page 12
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.
Frost Protection
The appliance is fitted with an internal Frost Thermostat,
however this device 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. 12 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 does not have a manual
operation lever to aid filling. Therefore to ease filling of the
central heating system an air bleed valve is fitted to this
diverter and must be opened during filling until water flows
out. The valve should then be closed. (Fig.16).
(1) DIRECT METHOD (Fig. 8)
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
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.

Installation Requirements - Page 13
To assess water hardness, immerse a test strip 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. For central
heating systems greater than 15kW it may be necessary to
use a higher "design temperature drop across system" to
meet the system pump head requirement. The design
temperature drop should not exceed 20°C (36°F). Fig. 9
indicates the amount of pump head available for the system.
The boiler resistance is already taken into account in this
curve.
HOW TO USE FIG. 9.
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.
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 adjustment
knob, located on the electronic modulation control board.
(Fig. 30).
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.

Installation Requirements - Page 14
1.10 Electrical Supply
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. OR a 3 A fused double-pole switch, having a 3mm contact separation on both poles can be used.
It is important that the point of connection to the mains should be readily accessible and adjacent to the combination boiler.

Installation Requirements - Page 15
1.11 Clearances around the Appliance.
Side Clearance:
The position selected for the appliance must provide the
following minimum clearance which is necessary for
operation and servicing, 25mm each side (side
clearances have 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.

2. Boiler Installation - Page 16
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 two separate cardboard
cartons.
(1). The Large Carton. The Boiler - Containing:-
i) The Combination appliance c/w User Instructions
(Note: Pipe tails and valves supplied on a vacuum
formed card).
ii) These Installation and Service Instructions.
iii) The wall fixing template.
(2). The Small Carton. 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.
Installation instructions are included with each main
pack. Make sure you have the flue you require.
a) Unpack the cartons and check the contents.
b) 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. (Fig. 15)
c) Remove the base cover by removing the two fixing
screws and push the cover towards the rear to release
d) 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
safely to one side.
e) 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.
f) At this point follow the Installation Instructions supplied
with the Flue System, then proceed as follows:-
g) Boiler Connections.
All connections to the appliance are supplied
unassembled in the boiler carton on a vacuum formed
card. Remove all fittings and assemble to the appliance.
(Fig. 16).
Note: When fitted, the Red levered central heating tail
(C.H.flow) should be to the left of the Blue.
2.2 Gas Connection
(Fig. 16)
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.

Boiler Installation - Page 17
2.3 D.H.W. Supply
a) The domestic hot water circuit does not need a pressure
relief valve, but it is essential to ensure that the pressure
of the cold water supply does not exceed 10 bar (145
lb/in), if in doubt it is advisable to install a pressure
reducing valve. The minimum pressure needed to
operate the domestic hot water system is 1 bar with a
flow of approximately 2.5 litres per minute.
b) Flush out all foreign matter from the supply pipe before
connecting to the appliance.
c) Connect the cold water supply to the 15mm isolating
cock.
Connect the hot water outlet pipe using a 15mm
compression fitting.
Note: Until hot water is available, the flow will be
restricted.
Note: The Cold Water Supply Isolating Cock
incorporates an automatic flow limiting device and water
strainer. If a lower flow is required there is a throttle
valve located below the D.H.W mini expansion vessel.
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 (i.e. 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.
2.4 C.H. Water Connections
(Fig. 16)
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)

Boiler Installation - Page 18
2.5 Pressure Relief Valve
The pressure relief valve is pre-set at 3 bar.
Install a pressure relief valve discharge pipe, 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. (Fig. 17) The discharge point must be such that it will
not be hazardous to occupants or cause damage to external
electrical components or wiring.
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.
Read Section 2.6 for information on Thermostats and Timers
2.6 Wiring the Appliance
The internal wiring of the appliance is shown in Figs. 42 & 46
. The wiring diagram is also on the inside of the front casing
panel.
a) Undo the single retaining screw on the top of 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), wire up the panel
referring to the termination label. (Fig. 18).
Note: Ensure that all cables pass through the wiring panel
bush/s and are securely fixed by the cable clamp/s.
If a room thermostat is to be fitted, remove the Red 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 timers lead to PL11 on
the modulation control board. (Fig. 30).
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'.
Secondary Pump.If a second pump is to be fitted to the
central heating system it should be sited on the return to the
boiler and electrically connected using a proprietary relay as
shown in Fig. 19.
c) Check all wiring and reposition the control panel.
d) Secure with screw provided.
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.

3. Commissioning - Page 19
The Puma 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 42.
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 pages
39 & 48.
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.