Hamworthy PUREWELL VariHeat he Manual

IMPORTANT NOTE
THESE INSTRUCTIONS MUST BE READ
AND UNDERSTOOD BEFORE INSTALLING,
COMMISSIONING, OPERATING OR
SERVICING EQUIPMENT

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NOTE: THESE INSTRUCTIONS MUST BE READ AND UNDERSTOOD BEFORE
INSTALLING, COMMISSIONING, OPERATING OR SERVICING EQUIPMENT.
THE PUREWELL BOILER IS INTENDED FOR USE AS A COMMERCIAL APPLIANCE AND IS
NOT CERTIFIED FOR USE IN DOMESTIC APPLICATIONS.
THIS BOILER IS FOR USE ON GROUP H NATURAL GAS (2ND FAMILY) I2H PLEASE
ENSURE RELEVANT INFORMATION REQUIRED WITHIN DOCUMENT IS FOUND
BEFORE FIRING BOILER.
THIS BOILER COMPLIES WITH ALL RELEVANT EUROPEAN DIRECTIVES.
PRODUCT IDENTIFICATION No.
PUBLICATION NO. 500001155
ISSUE ‘F’
January 2007
Purewell VariHeat he Boilers
Cast Iron, Pre-mix, Modular Boilers with Automatic
Ignition for Heating and Domestic Hot Water Installations
Installation, Commissioning
and Servicing Instructions
MODELS - PV65he, PV85he, PV105he & PV125he
NATURAL GAS I
2H

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CONTENTS
PAGE
1.0 INTRODUCTION.................................................................................................................................1
2.0 SUPPLY AND DELIVERY ..................................................................................................................2
3.0 SIZE AND SPACE REQUIREMENTS................................................................................................4
4.0 SITE LOCATION AND PREPARATION ............................................................................................6
4.1 Site Location
4.2 Gas Supply
4.3 Flues
4.4 Water Supply
4.5 Electrical Supply
5.0 BOILER ASSEMBLY........................................................................................................................11
5.1 Flue Pipe
5.2 Water Connections
5.3 Electrical Connections
6.0 PRE-COMMISSIONING....................................................................................................................13
6.1 Gas Supply
6.2 Ventilation
6.3 Pipework, Valves and Pump
6.4 Flue
6.5 Electrical
7.0 CHECKS PRIOR TO LIGHTING ......................................................................................................14
7.1 Boiler Gas System Leak Check
7.2 Checks Prior to Lighting the Boiler
7.3 Initial Lighting
7.4 Combustion Checks
7.5 User Instructions
8.0 CONTROLS OPERATION................................................................................................................19
8.1 Starting Up
8.2 Standby
8.3 Pump Kick
8.4 Lockout
8.5 Heat Demand
8.6 Data Logging
8.7 Display Screen ..................................................................................................................................28
9.0 FAULT FINDING...............................................................................................................................33
10.0 SERVICING.......................................................................................................................................33
11.0 REPLACEMENT OF FAILED COMPONENTS................................................................................35
11.1 Igniter and Flame Probe Assembly
11.2 Temperature Limiter
11.3 Main Gas Valve
11.4 Combustion Fan
12.0 RECOMMENDED SPARES..............................................................................................................39

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PAGE
APPENDICES
APPENDIX A GAS DATA .............................................................................................................................40
APPENDIX B ELECTRICAL CONNECTIONS AND CONTROLS ...............................................................41
APPENDIX C FLUE DATA............................................................................................................................43
APPENDIX D VENTILATION ........................................................................................................................46
APPENDIX E WATER DATA ........................................................................................................................48
PICTORIAL AND DIAGRAMATICAL DATA
Figure 2.1 Boiler Delivery ...........................................................................................................................2
Figure 2.3 Boiler Package Dimensions ......................................................................................................3
Figure 2.5 Header Kit Package Dimensions ..............................................................................................3
Figure 3.1 Dimensions and Clearances .....................................................................................................4
Figure 3.2.1 Manifold Dimensions for a 2 Boiler Installation.........................................................................4
Figure 3.2.2 Manifold Dimensions for a 3 Boiler Installation.........................................................................5
Figure 3.2.3 Manifold Dimensions for a 4 Boiler Installation.........................................................................5
Figure 4.2 Gas Connection Point ...............................................................................................................6
Figure 4.3 Flue Connection Point...............................................................................................................7
Figure 4.4 Water Connection Points ..........................................................................................................8
Figure 4.5.1 Boiler Condensate Pipework Installation ..................................................................................9
Figure 4.5.2 Position Of Condensate Connection On Boiler ........................................................................9
Figure 4.5 Electrical Connections ............................................................................................................10
Figure 5.2.1 Rear Water Connections.........................................................................................................11
Figure 7.1.1 Test Point Locations On Gas Valves ......................................................................................12
Figure 7.1.2 Gas System Leak Check ........................................................................................................12
Figure 7.2.1 Gas Isolating Valve .................................................................................................................15
Figure 7.3.1 Boiler Fascia Display ..............................................................................................................15
Figure 7.3.2 Start Up Display Sequence.....................................................................................................16
Figure 7.4.1 Removal of Sample Point Plug ...............................................................................................17
Figure 7.4.2 Combustion Analyser Probe setting .......................................................................................17
Figure 7.4.3 Fan Assembly PV65he & PV85he ..........................................................................................18
Figure 7.4.4 Fan Assembly PV105he & PV125he ......................................................................................18
Figure 8.0 Boiler Fascia Panel .................................................................................................................19
Figure 8.1 Burner Control Logic Diagram ................................................................................................20
Figure 8.5.1 Priority Heat Demands............................................................................................................21
Figure 8.5.2 Temperature Offset and Hysteresis ........................................................................................22
Figure 8.5.2.3 Cascade Sequence.................................................................................................................23
Figure 8.5.2.4.1 Dividing Cascade Power.........................................................................................................24
Figure 8.5.3.1 Flow Temperature Control ......................................................................................................25
Figure 8.5.3.2 Power Control .........................................................................................................................25
Figure 8.5.4 CH Heat Curve........................................................................................................................26
Figure 8.5.7.2 Control of Flow Temperature Gradient ...................................................................................26
Figure 8.5.7.3 Step Modulation Control .........................................................................................................27
Figure 8.7 Display Status Screens...........................................................................................................29
Figure 8.7.1.2 Water Temperature Sensor Screen........................................................................................30
Figure 8.7.1.3 Fan Speed and Flame Ionisation Screen ...............................................................................30
Figure 8.7.1.4 Remote Control Input Status Screen ......................................................................................30
Figure 8.7.1.5 Cascade Status Screen ..........................................................................................................30
Figure 8.7.1.6 Cascade Information Screen ..................................................................................................31
Figure 8.7.2.1 Access Status Screen.............................................................................................................31
Figure 9.0 Boiler Wiring Schematic..........................................................................................................32
Figure 11.1 Hot Surface Igniter and Flame Sensing Probe Positions ......................................................36
Figure 11.3 Gas Valve Assembly ..............................................................................................................36
Figure 11.4 Combustion Fan Assembly ....................................................................................................37
Figure 11.5 Casing Assembly ....................................................................................................................37
Figure 11.6 Heat Exchanger Assembly .....................................................................................................38

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FIGURES PAGE
Figure A1 Gas Data .................................................................................................................................40
Figure B1.1 Electrical Supply......................................................................................................................41
Figure B1.2 External Control Wiring for Multiple Boiler Installation............................................................42
Figure C1 Flue Data.................................................................................................................................43
Figure C1.1 Flue Resistance ......................................................................................................................45
Figure C1.2 Open Flue (Natural Draught) B23 Flue System......................................................................45
Figure D1 Mechanical Ventilation Flow Rates .........................................................................................47
Figure E1 Water Data ..............................................................................................................................48
Figure E1.1 Cold Feed and Vent Pipe Sizes ..............................................................................................48
Figure E1.2 Typical Piping Layouts ............................................................................................................49
Figure E1.3.1 Schematic for Single Boiler System........................................................................................51
Figure E1.3.2 Schematic for Single Boiler, Primary Circuit System ..............................................................51
Figure E1.3.3 Schematic for Multiple Boiler (0~10V) Primary Circuit System...............................................52
Figure E1.3.4 Schematic for Multiple Boiler (Cascade) Primary Circuit System...........................................52

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1.0 INTRODUCTION
1.1 A competent person holding ‘CORGI’ registration
or equivalent must install this boiler. All installations
MUST conform to the relevant Gas Safety and
Building Regulations. Health & Safety requirements
must also be taken into account when installing any
equipment. Failure to comply with the above may
lead to prosecution.
1.2 These instructions are for Group H Natural Gas
(2nd Family) only. The information relating to Natural
Gas firing is to be found in Appendix ‘A’. Boilers MUST
NOT use gas other than that for which they were
designed and made.
1.3 The Purewell VariHeat he is a fully modulating,
pre-mix, gas fired boiler manufactured from horizontal
cast iron sections.
The boiler is floor mounted and is intended for the
heating of Commercial and Industrial premises. It
may also be used to supply hot water for these
premises via an indirect cylinder.
1.3.1 Each boiler module has a dedicated
microprocessor based boiler management system,
controlling and monitoring all safety and functional
aspects of the boiler performance and it’s integration
with external system controls.
1.3.2 The Purewell VariHeat he boiler is delivered to
site fully assembled fitted with it’s casing and
controls. Care should be taken when manoeuvring
the boiler into position to avoid damage.
1.3.3 Each of the boiler models is designed for direct
connection to a flue system. The flue outlets from
more than one unit may be connected to a single
chimney. No draught diverter is fitted to the boiler nor
is a fixed diverter required in the flue system.
However a draught stabiliser is recommended for
some installations—see Appendix ‘C’ (Page 43).
1.3.4 The Purewell VariHeat he has a low water
content and minimum flow rates MUST be maintained
above the recommended levels shown in Appendix
‘E’ (Page 47)
1.4 If the boiler is to be connected to an un-vented
(pressurised) heating system, care must be taken to
ensure all extra safety requirements are met and that
the relevant interlocks will shut down the boiler(s)
should a high or low pressure fault occur.
The pressurisation unit must also incorporate a low
level water switch, which protects the water pumps,
and will directly or indirectly shut down the boiler
plant should a low water condition occur.
Consideration should also be given to the maximum
working pressure of the boiler as given in Appendix
‘E’. Consult Hamworthy Heating Technical
Department for help or assistance if in doubt.
1.5 The Purewell VariHeat he boiler is not suitable for
direct connection to domestic hot water supplies or
gravity fed heating systems.
1.6 The Purewell VariHeat he boiler can be installed
with either reverse return water flow layout or with
single pipe header layout (non HHL supply). See
Appendix E for typical schematic layout.
1.7 It is good practice in all heating installations to
use some form of water treatment to reduce
formation of lime scale and black iron oxide sludge.
The high efficiencies produced by the Purewell
VariHeat he Boiler can easily be reduced by lime
scale formation. If a pressurisation unit is used, it is
prudent to include an hours run meter to give an
indication of pump running time and hence raw water
make-up. Any leaks should be attended to as soon as
possible to avoid scale build up within the boiler's
waterways.
1.8 Each Purewell Variheat he module is supplied
with volt free contact outputs for Normal Run,
Overheat and General Fault, and 0~10v analogue
control input compatibility. In addition, the control
system allows the connection of multiple boilers on
an RS485 bus connection to enable Cascade control
of up to 8 multiple boilers by the selection of Master/
Slave configuration.
1.9 Options
1.9.1 Optional reverse return header kits are
available in 2, 3 & 4 boiler configuration covering
models 65he - 85he & 105he - 125he. These kits
incorporate all necessary valves and interconnecting
pipework. Refer to individual kit instructions for
details.
1.9.2 Controls peripherals
1.9.2.1 External Sensor - For single boiler
installations, an external air temperature sensor is
available to allow direct weather compensation on the
boiler.
For multiple boiler installations under Cascade control
from the boiler controls, the same sensor may be
connected to the Master to provide direct
compensation on the Cascade.
1.9.2.2 Cascade Control kit - For multiple boiler
installations under Cascade control, a mixed flow
sensor is supplied to influence the modulation of the
Cascade against the setpoint.

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2.0 SUPPLY AND DELIVERY
Your boiler is despatched to site as a pre-assembled and tested unit. Each boiler is delivered by a tail lift vehicle
and lowered to ground level. It is the installers responsibility to convey the boiler to the plantroom.
The base of each boiler is specially designed to accept a standard pallet truck. This allows the boiler to be
manoeuvred into position without any pallets to remove. Additionally the boiler is designed to pass through a
standard doorway where access is restricted.
NOTE: The boiler is supplied with cardboard corner protection and shrink wrapped for protection during handling.
However, when manoeuvring the boiler, care must be taken to avoid damage to the casing.
The boiler must be kept upright during handling. Care must be exercised to avoid toppling the boiler as this will
result in damage.
The flue connection & condensate trap to the boiler are packaged separately to avoid damage. The flue
components consist of an adaptor elbow, gasket and straight length of 150mm diameter flue pipe. The condensate
trap is supplied loose beneath the front cover.
Figure 2.1 - Boiler Delivery

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Model Depth Width Height Weight
Purewell VariHeat he 65
1090mm 550mm 1310mm
205kg
Purewell VariHeat he 85
Purewell VariHeat he 105
Purewell VariHeat he 125
277kg
Figure 2.3 - Boiler Packaged Dimensions
Delivery Verification
When taking delivery please ensure that you have received the correct number of boilers and ancillary packages to
fulfil your order. If any item is missing please contact our after sales service team. Please provide details of your
order such as order number and contract number as well as a detailed description of the missing item.
Reverse Return Header Sets
Where reverse return header sets are used these are packaged separately from the boilers.
Ancillary items such as isolation valves and flexible boiler connectors are packaged in a cardboard box on the
same pallet. The whole is shrink wrapped for security and basic protection.
Model Configuration Length
mm
Weight
kg
65 - 85 he 2 boilers 1250 57
65 - 85 he 3 boilers 1784 95
65 - 85 he 4 boilers 2318 133
105 - 125 he 2 boilers 1250 112
105 - 125 he 3 boilers 1784 178
105 - 125 he 4 boilers 2318 300
Figure 2.5 - Header Kit Packaged Dimensions

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3.0 SIZE AND SPACE REQUIREMENTS
3.1 The Purewell VariHeat he boiler range has been designed to utilise minimum floor space, therefore it is important the
plantroom has sufficient ceiling height to allow for installation and connection to the flue system.
A minimum distance of 50mm must be maintained from easily flammable materials
Also important is allowance for sufficient access at front, sides and rear of boiler for flue and pipework connections.
Ensure a minimum height of 150mm above the boiler for removal of the covers.
Do not run cabling through the top or display covers.
See Figure 3.1 below.
3.2 The Hamworthy Heating Ltd water manifold kit is designed to provide a compact solution for connecting the boilers to
the gas supply and flow and return water connections. (Refer to the Manifold Kit Installer’s Guide for specific details.)
Figure 3.1 - Dimensions and Clearances
Figure 3.2.1 – Manifold Dimensions for a 2 Purewell VariHeat he boiler installation
393
150
71
260
1233
16
9
100 FLUE
330
515
456
1311
460
171
11 6
865
534
DATALABLE
150 (MIN RECOMM END ED)
RETURN R 2" (P V105/ 125he)
FLOW R2" (PV105/125he)
WARNING LABLE
F RONT VIEW A LL MODELS SIDE VIEW ALL MOD ELS REAR VIEW ALL MOD ELS
GAS R1"
(AL L M ODE LS)
FLOW R2" (PV65/85he)
RE TURN R 2" ( PV65/ 85he)
PIPEWORK
570
470
12 90
C
D
Dimension
(mm)
C
D
PV 65 /8 5h e
1650
1400
PV105/125he
1780
1540
Boiler Mode l
REAR ELEVATION ENDELE VATIO N
DN PN80 16

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Figure 3.2.2 – Manifold Dimensions for a 3 Purewell VariHeat he boiler installation
Figure 3.2.3 – Manifold Dimensions for a 4 Purewell VariHeat he boiler installation
Safety Valve: As each kit is provided with a 3 port isolating valve for use on the flow pipe, individual safety valves are not
required on each module and a common valve can be fitted in the combined flow pipe. However, each boiler has a Rp1”
connection (plugged) in the rear of the boiler heat exchanger assembly for use on applications where module isolating
valves are not of the 3 port type..
47 0
C
23 5 8
D
REA R E LEVAT ION ENDELEVATION
Dimension
(mm )
C
D
PV65/85he
1650
1400
PV105/125he
1780
1540
Boiler Model
57 0
DN PN
80 16
470
C
D
1824
RE AR ELEVAT ION ENDELEVATION
D imens io n
(mm)
C
D
PV65/85he
1650
1400
PV105/125he
1780
1540
Boiler Model
57
0
DN PN
80 16

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4.0 SITE LOCATION AND PREPARATION
4.1 Site Location.
• The floor or plinth for the boilers and water manifold kit must be both flat and level to
ensure correct alignment of fittings and connections.
• The floor or plinth must be sufficiently strong to support the weight of both the boilers
and manifold kit where used.
• The floor or plinth must be fireproof in accordance with BS 6644.
• The plantroom must have sufficient space for installation of boilers, manifold kits,
pipework, pumps, controls, flues, ventilation, access and servicing, and other items of
plant.
4.2 Gas Supply.
• Gas supply pipes must be in accordance with BS 6891 or IGE/UP/2
• Gas supply connection to the boiler must not be smaller than the connection on the
boiler - R1”
• Gas installation must be soundness tested to BS 6891 or IGE/UP/1 & IGE/UP/1A.
• Gas installation must be purged to BS 6891 or IGE/UP/1 & IGE/UP/1A.
• Inlet gas pressure to boiler should be nominal 20mbar (minimum 17.5mbar) dynamic at
the connection to the boiler.
• Boiler house gas isolation valve must be clearly identified and installed close to the
entrance / exit.
Figure 4.2 – Gas Connection Point
R 1” Gas Connection

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Figure 4.3 – Flue Connection Point
Flue Connection as delivered
4.3 Flues
• Flue termination, routing and construction must comply with the requirements of the
Clean Air Act 1993—Chimney Memorandum, BS 6644 BS 5440 and IGE/UP/10.
• Any flue must be self supporting and separable from the boiler for servicing
requirements.
• Due to the possible flue gas temperature, 60 — 190°C, consideration must be given to
the construction and material of the flue system with fully sealed joints due to pressure
and condense in flue.
• Flue construction is recommended of a twin wall, insulated type to maintain buoyancy
within the flue.
• Care should be taken to ensure that the flue system is installed in such a way that any
condensation produced on start up, will drain away naturally.
• Horizontal flue runs must be kept as short as possible and be inclined at minimum 2°
towards the termination.
• The flue system must be designed acknowledging that there may be a positive pressure
generated by the boiler combustion fan. Refer to Appendix C - Fig C1.
• Connecting flue systems may be smaller in internal diameter than the boiler
connection. Refer to Hamworthy Heating Technical Dept for assistance.
Flue Connection fitted
Flue fixing bracket
Flue Pipe
Elbow

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4.4 Water Supply
• Feed and Expansion tanks to comply with static height requirements of BS6880 &
BS6644.
• Cold feed and open vent pipes to comply with requirements of BS 6644.
• Pressurised system to comply with BS 7074.
• It is recommended that the system pipework is flushed twice before water
treatment.
• In hard water areas precautions such as water treatment should be implemented to
prevent the build up of sludge and scale.
• Leaks in the system pipework should be fixed to prevent dilution of water treatment.
• Maximum working water pressure is 7 bar.
• For minimum water pressure see Appendix ‘E’ - Water Data (Page 47)
Flow Connection
Figure 4.4 – Water Connection Points
Return Connection
Model Type
PV65he & 85he
Model Type
PV105he & 125he
Condensate Take-Off

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4.5 Condensate Connections
• Provision must be made for removal of condensate from the boiler and flue system.
• Condense is mildly acidic, typically pH 3 - pH 5.
• Condense pipework must be non-corrosive and not copper. Hamworthy recommend
32mm dia. Plastic waste pipe.
• Condense may be discharged to a standard drain subject to National or Local
regulations.
Boiler Condensate
Connection
(32mm o/d)
Figure 4.5.1 - Boiler Condensate Pipe Work Installation
Figure 4.5.2 – Position Of Condensate Connection On Boiler
• Location of condense
pipework should prevent
freezing within
tundishes, traps and
pipework.
• Do not allow blockage or
damage to the
condensate trap.
• The connection to the
boiler condense drain
accepts a straight push-
fit coupling for 32mm i.d.
plastic waste pipe.

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4.5 ELECTRICAL SUPPLY
WARNING! THIS APPLIANCE MUST BE EARTHED IN ACCORDANCE WITH IEE
REGULATIONS
• Boiler electrical supplies must not be switched by a time clock.
• Boilers are suitable for 230Volt, 50Hz supply.
• External fuses should be rated for 6 amps
• Wiring must be completed in heat resistant cable size 1.0mm² csa.
• Each module should have individual means of isolation.
• Electrical isolators must facilitate complete electrical isolation.
• Electrical isolators must have contact separation of minimum 3mm in all poles.
• Electrical isolators must be installed in readily accessible locations.
• Electrical supplies to boiler modules should only serve the boiler.
• Where volt free contacts are used, these too must be individually isolatable.
• Time clock control should be via the boiler modules Remote On/Off circuit (30V DC).
Any circuit connected to the Remote On/Off MUST be volt free
ADDITIONAL INFORMATION REGARDING ELECTRICAL SUPPLIES IS GIVEN IN BS
EN60335, Part 1.
NOTE: The appliance must be isolated from the electrical supply if electric arc welding is
carried out on connecting pipework.
FOR DETAILED WIRING INSTRUCTIONS SEE SECTIONS 5.3, 9.0 & APPENDIX B
Figure 4.5 - Electrical Connections
Earth
Neutral
Neutral
Neutral
Live
Live
Live
Ov erheat Ov erheat
Norm al Run
Norm al Run
Common Fault
Common Fault
0~1 0v
Signal
Outside
Sensor
Sensor
Master Screen
Slave S creen
Ca sc ade
Ground
Ground
Remote On/ Off
Remote On/Off
Mains 6A
Signal
Sensors
230v~50Hz Volt free contacts
Max 230 v 2A
Cascade
Shunt Pump Output 1 A
Primary Pump Output 1A
4~20mA

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5.0 BOILER ASSEMBLY
General
Boilers are despatched to site as fully assembled units. The flue pipe, condensate drain connection and pipework
manifold set (where applicable) are the items that will need assembling on site.
During assembly it is important to take care to prevent damage to the boiler casing. DO NOT STAND ON THE
CASING PANELS.
Boiler positioning must allow the minimum clearances detailed in Section 3.0 to facilitate access for flue and
pipework connections as well as maintenance. Boilers can be positioned side by side, no clearance is necessary.
5.1 Flue Pipe
So as to avoid damage, the flue connecting pipe is supplied separately.
Fit the elbow to the base of the boiler and secure using the gasket and 4 - M8 x 16 Hex Head Screws. Moisten the
lip seal and engage the flue pipe into the elbow. Secure the flue pipe to the boiler casing using the bracket
supplied.
5.2 Water Connections:
Connecting pipework must be self-supporting to avoid stress on the boiler connections. Local unions are
recommended in the pipework to facilitate future servicing requirements.
The following connections are provided on each boiler module;
Figure 5.2.1 - Rear Water Connections
Flow R2” Male thread. Indicated by a
red dot on boiler.
Gas R1” Male thread.
Return R2” Male thread. Indicated
by a blue dot on boiler.
Rp1”
Safety Valve
(behind flue pipe)
Condensate Trap

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Open Vented Systems
Boilers must not be capable of isolation from the vent pipe. Valves between boiler and vent pipe to be three way
type such that when boiler is isolated from vent pipe it is open to atmosphere. Safety valves should be mounted
on the boiler using the connection provided.
Sealed Systems
Boilers must not be capable of isolation from the safety valve. Valves between boiler and safety valve to be three
way type such that when boiler is isolated from safety valve it is open to atmosphere. Hamworthy Heating Ltd
provide a connection on the boiler for the safety valve .
Where using Hamworthy Heating Ltd pipework kits, assembly of these is detailed in the Instruction manual
supplied with kit.
5.3 Electrical Connections:
The following electrical connections are provided on each module on a rail at the base of the front of the boiler.
• Supply: Live, Neutral and Earth. See Section 4.6 for details.
• Live and Neutral connections for Shunt pump or Primary Pump
• Boiler Overheat Fault Alarm Signal Output
• Common Fault ie A Boiler Ignition Lockout Or Fault Alarm Signal Output
• Boiler Normal Run Signal Output
• Remote On/Off
• 0-10v Analogue Control Signal Input
• External sensors
• Cascade Management of Multiple Boiler Installations

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6.0 PRE-COMMISSIONING
The following checks must be carried out before the boiler is commissioned.
6.1 Gas Supply.
Ensure that gas installation pipework and meter have been soundness tested and purged to IGE/UP/1 or IGE/
UP/1A as appropriate. Test and purge certificates should be available for viewing.
6.2 Ventilation
Ensure that ventilation and air supply to plantroom is correct - refer to Appendix D (page 46). Air supply around the
rear of appliance is unobstructed.
6.3 Pipework, Valves and Pump
Ensure that;
• Pipework and valve arrangement is installed to Hamworthy Heating recommendations.
• Circulating system is full of water, vented and pressurised appropriately.
• Circulation pump is fitted, working and interlocked where required.
• Pipework connections to boiler are fitted correctly.
• All necessary isolation valves are open.
• Safety valve is correctly sized and located.
• Heat load is available.
6.4 Flue
Ensure that;
• Flue system is correctly designed and installed to suit boilers.
• Flue passages to chimney are clear.
6.5 Electrical
Ensure that;
• Electrical connections are correct and isolatable.
• External controls are operational.
WARNING: IF THE FRONT COVER IS REMOVED WHILST THE BOILER IS OPERATIONAL,
CARE MUST BE TAKEN WITH ELECTRICAL COMPONENTS AND ACCESS TO PRIMARY
INSULATION.

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7.0 CHECKS PRIOR TO LIGHTING
IMPORTANT: BEFORE PROCEEDING TO LIGHT THE BOILER, ENSURE THAT THE PRE-
COMMISSIONING CHECKS HAVE BEEN CARRIED OUT AND THE RESULTS SATISFACTORY.
7.1 Boiler Gas System Leak Check
Ensure that the appliance manual gas service valve is in the OFF position. Although the boiler receives a gas
leak check and gas train component integrity check prior to leaving the factory, transport and installation may
have caused disturbance to unions.
A procedure guide is given below. Care must be taken not to allow leak detection fluid on or near any electrical
parts or connections.
Figure 7.1.2 - Gas System Leak Check Diagram
Note: - Main gas supply pressure - G20 - 20mbar
To Check Valve B
1) Turn off the electrical power and gas to the appliance.
2) By unscrewing screw at Position X of Figure 7.1.1 remove the red gas pressure switch (L.H.S picture) or loosen
the test point valve plug (R.H.S picture).
3) Connect the manometer to gas valve test point.
4) With A, B closed open C and monitor manometer over a 2 minute period, a rise indicates a leak on valve B.
5) Reinstall red gas pressure switch or shut valve plug in test point.
To Check Valve A
1) Repeat steps 1, 2, 3 & 5 above.
2) Open C.
3) Open B to produce the main gas supply pressure between A and B.
4) Close B
5) System may be considered sound if over a period of 2 minutes any drop in pressure is less than 0.5 mbar
(0.2" wg.).
NOTE: Allow a manometer stabilisation period of approximately 1-minute before each 2 minute check period. Fol-
lowing soundness tests close valve B and remove manometer connections and tighten test points.
Figure 7.1.1 - Test Point Locations On Gas Valves
Position X
(Test Point)
Low Gas
Pressure
Switch

HAMWORTHY HEATING LTD
15
PUREWELL VariHeat he 500001155/F
7.2 Checks Prior to lighting the boiler
NOTE! Refer to Appendix A for Natural Gas maximum gas inlet pressure for normal operation.
The following checks must be made prior to lighting the boiler.
If satisfactory, refit the bulb in the pocket and secure
with the clip. Ensure that all thermostat bulbs/sensors
are fully inserted into the pockets. The flow and return
temperature sensors are located at the rear of the
boiler in the flow and return pipes.
3) Check setting of both temperature limit thermostat
and control thermostat. The limit thermostat is set at
95°C. To remove the limit thermostat, found on the rear of
the display fascia bracket removing the plastic display
cover and unscrew the fixing screws securing the
thermostat from its mounting plate.
The control thermostat is factory set to a flow temperature
of 85°C and must be re-set to suit the application using
the process detailed in section 8.7.2.1 - Controls
Operation
4) To ensure correct ignition of the boiler it is
recommended to check the resistance of the hot
surface igniter. This should be checked cold, using a
suitable ohmmeter, by disconnecting the igniter from
the control panel cable and measuring the resistance
across the pins of the 2 way connector. The reading
should be between 70 and 110 ohms.
7.3 INITIAL LIGHTING
Only competent persons registered for working on non-domestic gas appliances should attempt the following
operations. Before attempting to commission any boiler, ensure that personnel involved are aware of what action
is about to be taken.
Record all readings for future reference on relevant commissioning sheet.
Allow system to warm up sufficiently to check operation of control thermostat.
A combustion check must be taken when first commissioning the boiler. A sampling point is provided in the base of the
boiler.
NOTE! Care should be exercised when the boiler is firing as the flue components can achieve temperatures, which
could cause injury if touched.
Figure 7.2.1 Gas Isolating Valve
Boiler On/Off - Enter - Reset
Gas
Isolating
Valve
1) Ensure that the gas supply is connected but turned to the "off" position. Any unions or fittings are correctly tight-
ened, test points are closed, and that the ignition and probe leads are connected correctly.
2) Ensure the electrical mains supply is correctly connected but the boiler isolator(s) are switched off. Check all
wiring loom connections such as fan and gas valve, are correct and secure. Test the operation of the safety tem-
perature limit thermostat (Limit Stat) by removing the clip & bulb from the pocket in the front of the heat
exchanger, and carefully apply a heat source to the bulb. The Limit Stat reset button should lift & protrude through
the hole in the controls fascia. To reset, firmly press the button through the access hole in the controls fascia
using a terminal screwdriver.
Gas Pressure
Test Point
Position Limit
Thermostat
Reset
Figure 7.3.1 Boiler Facia Display
Position Of
Viewing
Window