Potterton Osprey CF 180 Installation and maintenance instructions

Installation & Service Instructions Osprey CF
125 – 220
About the Boiler See inside cover for models covered by these instructions.
This Floor Standing Cast Iron Gas Boiler is available as Conventional Flue.
This boiler is for use with Natural Gas (G20) at 20mbar or Propane Gas (G31) at 37mbar and
for use in GB & IE.
About Safety The Gas Safety (Installation and Use) Regulations 1994 (As Amended) & The Gas
Safety(Installation and Use) (Amendment) Regulations 1996.
‘‘ 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.
Leave these instructions with the user for use on future calls.

Contents - Page 2
Technical Data ................................................................. 3The models covered by these instructions are:-
Introduction...................................................................... 5Osprey 125 - G.C. No. 41 589 33
Health & Safety Information...................................... 5Osprey 150 - G.C. No. 41 589 44
Codes of Practice...................................................... 5Osprey 180 - G.C. No. 41 589 45
Osprey 220 - G.C. No. 41 589 62
1. Installation Requirements ...................................... 6
1.1 Gas Supply....................................................... 6
1.2 Electricity Supply .............................................. 6
1.3 Location of Boiler.............................................. 6
1.4 Air Supply ......................................................... 7The boiler model and serial number are given
1.5 Flue System...................................................... 8on the boiler data label which is located on the
1.6 The System ...................................................... 9front outer casing fixing bracket.
2. Installation ............................................................. 13
2.1 Prepare the Boiler........................................... 13
2.2 Connect the Gas Supply................................. 14
2.3 Connect the Water Supply.............................. 14
2.4 Connect the Power Supply Cable................... 15
2.5 Install the Room Thermostat........................... 16
2.6 Install the Flue ................................................ 16
3. Commissioning ..................................................... 17
3.1 Commission the Boiler.................................... 18
3.2 Final Adjustments........................................... 19
3.3 Instruct the User ............................................. 19
3.4 Advise the User .............................................. 19
4. Service & Replacement of Parts.......................... 20
4.1 General Access .............................................. 21
4.2 Control Panel.................................................. 21
4.3 TTB Thermostat.............................................. 22
4.4 Boiler Thermostat........................................... 22
4.5 Overheat Thermostat...................................... 22
4.6 Burner Assembly ............................................ 22
4.7 Gas Valve....................................................... 23
4.8 Pilot Interrupter............................................... 23
4.9 Pilot Assembly................................................ 23
4.10 Burner............................................................. 23
4.11 Cleaning Heat Exchanger............................... 23
5. Wiring Diagrams...................................................... 24
6. Fault Finding ........................................................... 26
7. Short List of Spares................................................. 29 Fig. 1
SAFETY, PERFORMANCE & QUALITY
Osprey 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.

Technical Data - Page 3
Heat Input & Efficiency figures are
quoted as gross Boiler models
Maximum Rate 125 150 180 220
Output kW 35.0 43.0 52.8 64.5
Btu/h 119,420 146,716 180,154 220,074
Input kW 43.09 53.12 64.79 79.77
Btu/h 147,020 181,245 221,063 272,171
Gas rate (G20) m3/h 4.10 5.06 6.17 7.60
ft3/h 145 179 218 268
Injector Size mm 2.6 2.6 2.6 2.6
Burner Pressure mbar 12.8 12.2 13.3 13.8
Permanent Pilot mm 2 Holes Ø 0.29
Injector
Combustion g/s 30.56 33.89 39.44 47.50
Product Rate
Primary Flue Temp. °C 170 165 150 155
LPG Gas Rate(G31) kg/h 3.01 3.7 4.6 5.6
Injector Size mm 1.75 1.75 1.75 1.75
Burner Pressure mbar 36.5 36.5 36.5 36.5
Permanent Pilot mm 1 Hole Ø 0.24
Injector
Efficiency (Gross) %81.2 80.9 81.5 80.9
Injector Size mm 1.75 1.75 1.75 1.75
Water Content Litres 24 29 33 38
Appliance Weight kg 135 165 195 225
Nominal flow l/min 45.6 56.0 68.8 84.0
for temp. diff. of 11K
Pressure Loss mbar 9.7 18.7 27.5 55.9
for temp. diff. of 11K
Maximum Working Head 30m (3 bar)
Minimum Working Head 0.5m
Gas Supply Pressure G20 - 20mbar G31 - 37mbar
Gas Supply Connection 22mm Copper pipe with female compression fitting
Maximum Flow Temperature 85°C
Flow Connection 11/4/" Steel pipe, taper thread
Return Connection 11/4" Steel pipe, taper thread
Electricity Supply 230v ~ 50Hz Fused at 3A
Power Consumption 10 Watts (excluding pump)
Classifications CAT 11 2H 3P - B11Bs - IP20

TECHNICAL DATA - Page 4
Fig. 2

Introduction - Page 5
The Gas Safety (Installation and Use) Regulations 1994 (As
Amended) & The Gas Safety (Installation and Use)
(Amendment) Regulations 1996.
This 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 Plc) 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.
Osprey boilers are fully automatically controlled, floor
standing, conventional flued appliances using a cast iron
heat exchanger and are available in outputs ranging from
35.0 - 64.5 kW.
The boilers are designed for use on fully pumped open
vented or sealed water systems with an indirect hot water
cylinder.
THEY MUST NOT BE CONNECTED TO A DIRECT
CYLINDER.
The boilers are for use on Natural Gas (G20) and LPG
(G31).
Samples of the Potterton Osprey gas boilers have been
examined by Ctif, a France 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.
Delivery & Kits Available
The unit is delivered in one package, the boiler with fittings
and the flue spigot.
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 cause
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.
Codes of Practice
The boiler must be installed in accordance with: The Gas
Safety (Installation and Use) Regulations 1994 (As
Amended) & The Gas Safety (Installation and Use)
(Amendment) Regulations 1996. 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 Work
Regulations 1989".
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 Myson Ltd, could invalidate the
CE Certification and normal appliance warranty.

1. Installation Requirements - Page 6
1.1 Gas Supply
The meter and supply pipes must be capable of delivering
the required quantity of gas in addition to the demand from
any other appliances in the house and must be governed at
the meter.
If this is not achieved the local gas supplier must be
contacted.
A minimum 22mm gas supply pipe should be used up to the
inlet connection of the gas cock on the boiler. The pipe
diameter required will depend upon the length - see Section
2. and BS 5449: 1990 - Appendix B.
The complete installation must be 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 10W. There
must be only one common isolator for the boiler and its
control system and it must provide complete electrical
isolation. A plug complying with the requirements of BS 1363
(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
The boiler is not suitable for external installation. The boiler
must stand firm and level on a non combustible surface. No
special floor protection is needed, but finishes which soften
when warm e.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 draft diverter is in
free air according to the clearance dimensions shown in
Fig. 2.
The flue duct should not be 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 BS5440:1:1990, sub-clauses
3.3 and 4.2.5.
If the boiler is to be installed in a timber framed building it
should be fitted in accordance with the British Gas
publication- Part 19 - Building and Kitchen Work. If in doubt
advice must be sought from Potterton Myson.
Conventional flue boilers can be installed either in a kitchen
or utility room or (125 and 150 models only) inside a suitably
ventilated, purpose designed or modified compartment.
Where the installation of the boiler will be in an unusual
position, special procedures may be necessary and BS6798
and BS5546 give detailed guidance on this aspect.
A compartment used to enclose the boiler is only allowed if
the clearances shown in Fig. 2 and the air requirements of
BS 5440 Part 2 are followed to allow correct functioning of
the draft diverter (125 and 150 models only).
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.
The boiler requires the clearances shown in Fig. 2.

Installation Requirements - Page 7
Conventional Flue Models
1.4 Air Supply
The air requirements must meet BS 5440 Part 2 & BS 6644.
The room in which the boiler is installed must be ventilated.
Ventilation of the room containing the boiler shall include air
for combustion and correct operation of the flue (ie Draft
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 - Osprey 125 & 150 Only. The Osprey 180 & 220
must have high and low level vents in accordance with Table
1a.
The opening may be:
a) Directly into the room or space containing the boiler
(all models) or indirectly via an opening of at least
the same area (125 & 150 models only).
b) Via a duct either directly into the room or space (all
models) or indirectly via an opening of at least the
same free area (125 &150 models only).
Where air is drawn indirectly from outside through more than
two air vents refer to BS 5440 Part 2 - Osprey 125 &
models150 only.
Where an extraction fan is fitted in the room containing the
boiler, special ventilation requirements must be
implemented. Refer to BS 5440 Part 2 and BS 6644.
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 Osprey 125 & 150 Only. The Osprey 180 & 220
cannot be installed in a compartment except those specified
in BS 6644 using a monodraught system. Both high level
and low level air vents must communicate with the same
room or must be on the same wall to outside air (125 & 150
models only).
Ensure that all air inlets and outlets are always completely
free from obstruction.
Open Flue
Boiler In Room
Table 1
Combustion Air
Model Output kW Free Area cm²
Osprey 125 35 163
Osprey 150 43 208
Table 1a
Combustion Air - High and Low Level
Model High Level cm² Low Level cm²
Osprey 180 281 562
Osprey 220 315 630
Open Flue Boiler Compartment
Ventilated From Inside
OSPR017A
Table 2
Compartment Ventilation - Free Area
Model High Level cm² Low Level cm²
Osprey 125 388 776
Osprey 150 478 958
Fig. 3

Installation Requirements - Page 8
Fig. 4
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 and BS 6644.
Ideally a flue should rise vertically and any terminal or
termination point shall be positioned so that combustion
products can disperse safely at all times. Therefore for
practical purposes, the flue should have the shortest
possible run to external atmosphere within the limit of the
minimum length of 1 metre, with as near vertical rise as
possible, 90° bends should be avoided. The terminal must
be at least above roof level and of a type approved by British
Gas.
There should be at least 1000mm of vertical flue from the
boiler flue socket.
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 and BS 6644.
If an existing chimney is used, ensure that it is thoroughly
swept before lining or connecting the boiler.
Care should be taken to avoid condensation in the flue.
In the case of a pre-lined chimney, it must be connected to
the socket of the boiler flue hood with a length of purpose
made flue.
Where a chimney lined with a vitreous enamelled flue liner is
used, connect and seal a short length of purpose made flue
into the base of the pre-lined flue, to connect to the boiler.
The flue diameter should never be less than the diameter of
the flue spigot on the draft diverter.
Note: A separate 6 - 8" flue adaptor is supplied with the
boiler.

Installation Requirements - Page 9
1.6 The System
When installing the boiler on an existing system, the system
should be chemically cleaned prior to installation.
The boiler must be used on INDIRECT hot water systems
only. It is suitable for use only on fully pumped systems
which may be sealed or open vented.
The system should be designed so that the maximum static
head does not exceed 30m and a minimum of 500mm. See
Fig. 6.
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.
Fully Pumped Systems
The pump must be wired directly to the terminal block
(See Fig. 12) as it will allow the pump to be controlled by
the over-run device. This will ensure that the pump will
continue to run after boiler shuts down thus preventing
nuisance operation of the overheat thermostat.
Systems fitted with controls which allow the boiler to
operate when both the hot water and central heating
circuits are closed i.e. mechanically operated
thermostatic control valves, must be fitted with a by-pass
circuit capable of:-
1. Dissipating a minimum of 2kW.
2. Maintaining a minimum water flow through the boiler
of 8 L/min.
A suggested method of meeting these requirements by
using a bathroom radiator fitted with two lockshield
valves is shown in Figs. 6 & 7.
Diagrammatic layouts of a fully pumped open system
and a fully pumped sealed system are shown in Figs. 6
& 7. The central heating should be designed as such
that the minimum flow through the boiler is above 8
L/min.
Sealed Systems (Fully Pumped)
Installation
The installation must comply with the requirements of
BS 6798: 1987 and BS 5449: 1990. The British Gas
publication "British Gas Specification for Domestic Wet
Central Heating 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 on the
flow from the boiler before any valves. 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).

Installation Requirements - Page 10
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.
Boiler Heat Exchanger: See Technical Data
Small Bore Pipework: 1 litre per kW of system
output
Micro Bore Pipework: 7litres
Steel Panel Radiators: 8 litres per kW of system
output
Low Water Capacity Radiators: 2 litres per kW of system
output
Hot Water Cylinder (Secondary Store): 2 litres
If the system is extended, the expansion vessel volume may
have to be increased unless provision has been 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
85°C.
The vessel size can now be determined from the information
in Table 4 where V = System volume in litres.
Vessel Charge Pressure (bar) 0.5 10.
Initial System Pressure (bar) 1.0 1.0
Expansion Vessel Volume (litres) V x0.11 V x 0.087
Table 4.
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 excess
of safety valve setting. Single feed indirect cylinders 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
higher than the top point of the system, and connected
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 automatic
pressurisation and make-up unit as shown in Fig. 8.
Mains Connection
There shall be no connection to the mains water supply or to
the water storage tank which supplies domestic hot water
even through a non-return valve, without the approval of the
Local Water Authority.
Filling Point
The system shall be fitted with a filling point always on the
return at low level which incorporates a stop valve to BS
1010 and a double check valve (approved by the National
Water Council) to be fitted in this order from the system
mains, see Fig. 8.
Circulation Pump Selection
The resistance through the heat exchanger
when operating with a water flow rate
producing an 11°K temperature rise at
maximum boiler output are shown in Table
5. If other controls such as 2 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
and MUST be wired directly to the boiler
terminal block. It must be fitted with two
isolating valves which are positioned as
close to the pump as possible. Closing of
any valve must always leave the open vent
and pressure relief valve unobstructed.
Table 5. Hydraulic Resistance for 11k Temp. difference
Boiler Water Flow Hydraulic Resistance
Output kW Rate L/min mbar m
35.0 45.6 9.7 0.1
43.0 56.0 18.7 0.19
52.8 68.8 27.5 0.27
64.5 84.0 55.9 0.56

Installation Requirements - Page 11
Fig. 5
Fig. 6

Installation Requirements - Page 12
Fig. 7
Fig. 8

2. Installation - Page 13
2.1 Prepare the boiler
These instructions assume you have decided on where the
boiler will be located.
1. Carefully unpack the boiler.
2. Do not discard any packaging until all the items are
accounted for.
3. Position the boiler to ensure the draft diverter is the
required distance from the wall.
4. Remove the top panel - 2 screws.
5. Remove the front door - unhook and lift off.
6. Fit the flue spigot (supplied separately inside the case)
to the draft diverter.
Fig. 9

Installation - Page 14
Fig. 10
2.2 Connect the Gas Supply
1. Ensure that the gas supply is isolated.
2. Connect the gas supply to the gas cock using a 22mm
copper pipe, sliding it in from the back panel 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 pipe is selected in accordance with
BS 6891 so that an adequate gas supply to the boiler is
provided.
Do not turn the gas supply on at this stage.
2.3 Connect the Water System
1. Connect system pipework to the boiler. Arrange
pipework to ensure correct venting of pipes and boiler.
The pipe diameter required will depend on boiler model
and system design and may not be the same as boiler
flow and return tappings.
Note: Drain off taps should be installed at the lowest
points in the system.
The flow and return pipes on the boiler are made of steel
with a conical 11/4/" male thread.

Installation - Page 15
2.4 Connect the Power Supply Cable
1. The mains supply should be 230V 50Hz and fused at
3A.
2. The mains wiring to the boiler has to be connected
inside the control panel
Access to the Control Panel Wiring Block
a. Open the top panel of the boiler by unscrewing the
rear screws.
b. Turn the blocking bracket 'A' to the inside of the
boiler.
c. Open the control panel and turn as shown in Fig.
11.
d. Remove the 2 screws 'B'.
e. Lift metallic strip to enable access to the wiring
block 'C'.
3. Cable clamping is provided on the side panel and
control panel. Feed the cables through the cable holder
and clamps, 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.
4. The pump wiring should be routed as the mains wiring,
through the cable clamps and connected to the terminal
connections PL and PN - Fig. 12.
5. Take up excess slack in the cables between the
terminal block and the cable clamp, then tighten the
cable clamp screws.
Ensure sufficient slack is available to the cable clamps
to allow the control panel to hinge freely. Check by
opening the control panel.
6. Close the back panel of the control board and secure
using the two screws - see Fig. 12.
7. Close the control panel by turning it upwards and
pushing it onto hinge D.
8. Carry out preliminary electrical system checks i.e. Earth
Continuity, Short Circuit, Polarity and Resistance to
Earth.
Frost Thermostat:
If a Frost Thermostat is to be fitted, the connections
should be made in the wiring external to the boiler.
Do not switch on the electricity supply at this stage.
Fig. 11

Installation - Page 16
Fig. 12
2.5 Install the Room Thermostat
1. If a Room Thermostat is to be fitted, the connections
should be made in the wiring external to the boiler.
2.6 Install the flue
1. Install the natural draft flue according to BS 5440 and
Fig. 4.
2. The boiler is fitted with a spillage device that will trip the
boiler out under adverse conditions.

3. Commissioning - Page 17
Fig. 13
Important
The commissioning and boiler adjustment must only be
carried out by a suitably qualified personnel. Potterton
Myson Ltd. offer this service on a chargeable basis.
Important
When purging and testing the gas supply for gas
soundness open all windows and doors in the room.
Extinguish all naked lights, cigarettes, pipes, etc.

Commissioning - Page 18
3.1 Commission the Boiler
Open Vented Systems - Remove the pump
and flush the system thoroughly with cold
water. Re-fit the pump. Fill and vent the
system then check for leaks.
Sealed Systems - The system can be filled
using a sealed system filler pump with a break
tank or by any other method approved by the
Local Water Authority. Refer to Section 1.6,
'The System' on Page 9 of these instructions.
Remove the pump and flush the system
thoroughly with cold water. Re-fit the pump. Fill
and vent the system until the pressure gauge
registers 1.5 bar (21.5 lbf/in2) and check for
leaks. Raise the pressure until the safety valve
lifts, this should occur within ± 0.3 bar of the
preset lift pressure of 3 bar. Release water to
attain the correct cold fill pressure.
Step by Step Commissioning (tick box when done)
1The whole of the gas installation must be
checked for soundness and purged in
accordance with BS 6891.
2Check the water system for leaks and rectify
as necessary.
3Preliminary electrical system checks must be
carried out. They are:- Earth Continuity, Short
Circuit, Polarity & Resistance to Earth.
4Re-fit the front cover and controls panel.
5Set the rotary boiler switch on the user
controls to its minimum position and boiler
Standby switch to 'O' Off.
6If a programmer is fitted, set to the 'Off'
position.
7Turn the boiler gas service cock to the 'On'
position and then turn On the main gas supply.
8Ensure the system is full of water and that the
pump, radiator and any other isolating valves
are open.
9Switch On the main electricity supply at the
isolating switch or plug and socket.
10 If a programmer is fitted set it to the 'On'
position and check that the room and cylinder
thermostats, where fitted are set to high
temperatures.
11 i. Press control knob in lightly and turn. Align
off position with marker .
ii. Press control knob in lightly and turn. Align
ignition position with marker .
iii. Press control knob in firmly and hold, at the
same time press the ignition button. The
pilot flame should be visible at the pilot
window. If not press the ignition button until
the flame is established.
iv. When the flame is established hold the
control knob in for approximately 20
seconds before releasing. The pilot flame
should remain alight.
v. Press control knob in lightly and turn, align
full flame position with marker .
vi. Switch the boiler Standby switch to On.
12 With the main burner running, check for gas
soundness around the boiler using leak
detection fluid.
13 Allow the system to reach maximum working
temperature and examine for leaks. Set the
boiler Standby switch to 'O' and drain the
system whilst still hot.
Note: Should the boiler fail to operate correctly
refer to the Fault Finding Guide on Page 26, and the
boiler wiring diagram on Page 24 for further
information.
14 Re-fill and vent the system making a final check
for leaks.
On sealed systems adjust to the correct cold fill
pressure. Set the pressure gauge pointer to the
system design pressure.
If a by-pass circuit is fitted the by-pass valve
should be adjusted with the boiler operating
under minimum load conditions to maintain
sufficient water flow through the boiler to
ensure that the overheat thermostat does not
operate under normal conditions.

Commissioning - Page 19
3.2 Final Adjustments
1Use a pressure gauge to check the inlet and
burner pressures. See the
Technical Data section for figures.
2Turn the boiler on and allow to run for 10
minutes.
3Check that the inlet pressure is 20 mbar
Natural Gas (G20) and 37 mbar for Propane
(G31).
4Check that the burner pressure is in
accordance with the information in the
Technical Data section.
5If burner pressure adjustment is required turn
the pressure adjusting screw as required -
See Fig. 13.
6Check at the gas meter that the gas rate is
correct.
7Shut down the boiler, remove the pressure
gauges, re-fit the screws and check for gas
soundness.
8Re-fit the front door.
Control Thermostat
At its minimum and maximum settings, the
thermostat should control the water flow
temperature at approximately 55 °C - 85 °C.
Set the boiler Standby switch to OFF and
check that the main burner shuts down.
Pilot Burner
The pilot is pre-set and no adjustment is
required. When lit the pilot flame envelope
should just cover the electrode tip. If the pilot
flame is not as described, replace as covered
in Section 4.6 - Servicing & Replacement of
Parts.
Overheat Thermostat
The overheat thermostat is pre-set and no
adjustment is possible. It will require manual
re-lighting if an overheat condition occurs (the
pilot will extinguish).
Re-light as detailed on Page 18.
Other Boiler Controls
No further setting or checking is necessary as
all boiler mounted controls are designed so that
if a fault should occur they will fail safe.
External Controls
Check that any other external controls
connected in the system, such as clocks or
thermostats are correctly set and control the
boiler as required.
Spillage Device
Temporarily block the flue and check that the
boiler shuts down within 2 minutes (if the boiler
fails to shut down replace the spillage device as
shown in section 4.3 of the Service and
Replacement of Parts).
Unblock the flue spigot and the boiler should
automatically relight within 10 minutes.
3.3 Instruct the User
On completion of the installation, the installer
should demonstrate the operation of the boiler
and its associated controls.
3.4 Advise the User
1If a programmer is fitted set the time and
programme the required settings.
2Hand the Instructions for Use, these Installation
& Service Instructions (and the programmer
instructions) to the User and instruct in the safe
operation of the boiler and controls.
3Advise the User of the precautions necessary
to prevent damage to the system and to the
building in the event of the system remaining
inoperative during frost conditions.
4Advise the User that for continued efficient and
safe operation of the boiler it is important that
adequate servicing is carried out at least once
a year by a Potterton Service Engineer or a
C.O.R.G.I. Registered Installer.
5Leave a permanent card attached to the boiler
giving:
a. Name and address of installer.
b. Date of installation.

4. Service & Replacement of Parts - Page 20
Read these: To ensure continued efficient operation of the appliance, it is recommended that it is checked and
cleaned as necessary at regular intervals.
The frequency of servicing will depend upon the particular installation conditions and usage but in
general once per year should be adequate.
It is the law that any service work must be carried out by a competent person who is C.O.R.G.I.
Registered.
Before servicing, fire the appliance and check that the flames are blue. Yellow flame and excessive lifting
indicate poor combustion.
WARNING: Before commencing work set the boiler standby switch to 'O' Off and allow the appliance to cool, isolate
the electricity supply.
If the gas valve is to be removed turn off the gas supply at the appliance service cock.
IMPORTANT: Always test for gas soundness after completing any servicing of gas carrying components and carry out
functional checks of controls.
IMPORTANT: Ensure that the outer white case is correctly fitted.
Notes on Cleaning Boiler Components
Heat Exchanger
Place a sheet of paper under the heat exchanger (after removing the burner assembly) then using the brush (Supplied
with the boiler), scrape the flueway fin surfaces in a downward movement. This will ensure that most of the deposits will
be collected on the paper.
Burner
Brush the burner top and check that the flame ports are clear. Any blockage may be removed with a fine wire brush.
Turn the burner upside down and tap gently to remove any debris (Protect the electrode).
Electrode
If the electrode requires cleaning wipe the surface using a cleaning fluid.
Main Injectors
Omit this operation if the gas rate is correct, otherwise clean by blowing through. Do NOT clear the injectors with a pin
or wire.
Flue
Inspect the draft diverter and flue tube for blockage, condensation and integrity, rectify if necessary.