VOKERA Synergy 29 User manual

Installation
& Servicing
Instructions
THESE INSTRUCTIONS
TO BE RETAINED
BY USER

Contents
Design principles and operating sequence Page
1.1 Principle components 2
1.2 Mode of operation (at reset) 2
1.3 Mode of operation 2
1.4 Safety devices 2
Technical data Page
2.1 Central heating 3
2.2 Gas pressure 3
2.3 Expansion vessel 3
2.4 Dimensions 3
2.5 Clearances 3
2.6 Connections 3
2.7 Electrical 3
2.8 Flue details (concentric) 3
2.8A Flue details (twin pipes) 3
2.9 Efficiency 3
2.10 Pump duty 4
2.11 Emissions 4
General requirements (UK) Page
3.1 Related documents 5
3.2 Location of appliance 5
3.3 Gas supply 5
3.4 Flue system 5
3.5 Air supply 5
3.6 Water circulation 5
3.6.1 Pipework 6
3.6.2 Automatic by-pass 6
3.6.3 Drain cocks 6
3.6.4 Air release points 6
3.6.5 Expansion vessel 6
3.6.6 Filling point 6
3.6.7 Low pressure sealed system 6
3.6.8 Frequent filling 6
3.7 Electrical supply 6
3.8 Mounting on a combustible surface 6
3.9 Timber framed building 6
3.10 Inhibitors 6
General requirements (EIRE) Page
3.A1 Related documents 7
3.A2 Location of appliance 7
3.A3 Gas supply 7
3.A4 Flue system 7
3.A5 Air supply 7
3.A6 Water circulation 7
3.A6.1 Pipework 7
3.A6.2 Automatic by-pass 7
3.A6.3 Drain cocks 7
3.A6.4 Air release points 7
3.A6.5 Expansion vessel 8
3.A6.6 Filling point 8
3.A6.7 Low pressure sealed system 8
3.A6.8 Frequent filling 8
3.A7 Electrical supply 8
3.A8 Mounting on a combustible surface 8
3.A9 Timber framed building 8
3.A10 Inhibitors 8
3.A11 Declaration of conformity 8
Installation Page
4.1 Delivery 9
4.2 Contents 9
4.3 Unpacking 9
4.4 Preparation for mounting the appliance 9
4.5 Fitting the flue 9
4.5.1 Concentric horizontal flue 9
4.5.2 Concentric vertical flue 11
4.5.3 Twin flue system 12
4.6 Connecting the gas and water 14
4.6.1 Gas 14
4.6.2 Flow and return 14
4.6.3 Safety valve 14
4.6.4 Condense pipe 15
4.7 Electrical connections 15
4.7.1 Casing removal 15
4.7.2 Appliance terminal block 15
4.7.3 Connecting the mains (230V) input 15
Commissioning Page
5.1 Gas supply installation 17
5.2 The heating system 17
5.3 Initial filling of the system 17
5.4 Initial flushing 17
5.5 Pre-operation checks 17
5.6 Initial lighting 17
5.7 Checking burner pressures 17
5.8 Final flushing of the heating system 17
5.8.1 Inhibtors 18
5.9 Setting the boiler operating temperature 18
5.10 Setting the system design pressure 18
5.11 Regulating the central heating system 18
5.12 Final checks 18
5.13 Instructing the user 18
Servicing instructions Page
6.1 General 19
6.2 Routine annual servicing 19
6.3 Replacement of components 19
6.4 Component removal procedure 19
6.5 Pump assembly 19
6.6 Safety valve 19
6.7 Automatic air release valve 20
6.8 Water pressure switch 20
6.9 Pressure gauge 20
6.10 Primary thermistors 20
6.11 High limit thermostat 20
6.12 Printed circuit board 20
6.13 Gas valve 21
6.14 Integral time switch 21
6.15 Electrode, burner thermostat, burner & injectors 21
6.16 Flue fan 22
6.17 Main heat exchanger 23
6.18 Air pressure switch 23
6.19 Automatic by-pass 23
6.20 Expansion vessel 23
6.20.1 Expansion vessel removal 23
6.20.2 Expansion vessel removal 23
6.21 Latent heat collector 24
6.21A Dismantling the latent heat collector 24
6.22 Condense trap removal 24
Checks, adjustments and fault finding page
7.1 Checking appliance operation 25
7.2 Appliance mode of operation 25
7.2.1 Selector switch in the off position 25
7.2.2 Selector switch in the hot water only position 25
7.2.3 Appliance functions 25
7.2.4 Heating/HW mode 25
7.3 Checking and adjusting burner pressure 25
7.3.1 Setting the maximum burner pressure 25
7.3.2 Setting the minimum burner pressure 26
7.4 Combustion analysis test 26
7.5 Checking the expansion vessel 26
7.6 External faults 26
7.6.1 Installation faults 26
7.7 Electrical checks 26
7.7.1 Earth continuity test 26
7.7.2 Short circuit test 27
7.7.3 Polarity check 27
7.7.4 Reversed polarity or supply fault 27
7.7.5 Resistance to earth check 27
7.8 Fault finding 27
7.9 Fault codes 27-33
Wiring diagrams Page
8.1 External wiring 34
8.2 Installation of Vokera twin channel programmer 34
8.3 Typical control applications 34
8.4 Vokera time clock 34
8.5 Vokera room thermostat 34
8.6 “S” plan wiring 34
8.7 “Y” plan wiring 34
8.8 Other controls 34
Exploded diagrams Page
Table 1 - 5 39 - 44
L.P.G. instructions Page
10.1 Related documents 45
10.2 Technical data 45
10.3 Converting the appliance gas type 45
10.4 Gas supply 45
10.5 Gas supply installation 45
10.6 Checking and adjusting burner pressure 45
10.6.1 Setting the maximum burner pressure 45
10.6.2 Setting the minimum burner pressure 45

1
The Synergy is a high-efficiency system boiler with an
output of 28kW.The appliance - by design - incorporates
electronic ignition, circulating pump, expansion vessel,
safety valve, pressure gauge and automatic by-pass.
The Synergy is produced as room sealed, category
II2H3+ appliances, suitable for internal wall mounting
applications only. It is provided with a fan powered flue
outlet with an annular co-axial combustion air intake that
can be rotated - horizontally - through 360 degrees for
INTRODUCTION
various horizontal or vertical applications.The Synergy
rangecan also be used with theVokeratwinfluesystem.
The Synergy range is approved for use with C12 & C32
type flue applications.
This appliance is designed for use with a sealed system
only; consequently it is not intended for use on open
vented systems.
Fig. 1
Fig.1 General Layout
1 Safety Valve
2 Pressure Switch
3 Hydraulic manifold
4 Pump
5 Automatic Air Release Valve
6 Transformer
7 Main Burner
8 Electrode
9 Main Heat Exchanger
10 Latent Heat Collector
11 Condense Sensor
12 Flue Gas Analysis Test Point
13 Flue Outlet
14 Air Intake
15 Differential Analog Pressure Switch
16 Silicone Pressure Tube
17 Silicone Negative PressureTube
18 Fan Assembly
19 Combustion Chamber
20 Burner Temperature Control
21 Expansion Vessel
22 Gas Valve
23 Modulator Coil
24 Condense Trap
25 Status LED
26 Temperature Indicator
27 Central Heating Temperature Control
28 Combustion Switch
29 Timeclock Aperture (optional)
30 Pressure Gauge
31 Mode Selector Switch
5
6
9
11 12 13 14
23
1
2
3
4
7
8
10
15
16
17
18
19
20
21
22
24
25
26
27
28
29
30
31

2
1.1 PRINCIPLE COMPONENTS
●A fully integrated electronic control board
featuring electronic temperature control, anti-
cycle control, pump over-run, self-diagnostic
fault indicator, full air/gas modulation.
●Low-water-content, copper heat exchanger.
●Electronic ignition with flame supervision
●Integral high-head pump
●Fan
●Expansion vessel
●Analogue pressure switch (PAD)
●Water pressure switch
●Two-stage gas valve
●Pressure gauge
●Safety valve
1.2 MODE OF OPERATION (at rest)
When the appliance is at rest and there are no
requests for heating or hot water, the following
functions are active:
●2-stage frost-protection system - the frost-
protection system protects the appliance
againsttherisk of frost damage.Thefirststage
enables activation of the pump should the
temperature of the appliance fall to 7°C. The
second stage becomes active when the
temperature has dropped to 3°C. Should the
secondstagebecomeactive,theappliancewill
function on minimum power until it reaches
30°C.
●anti-block function – the anti-block function
enables the pump to be energised for short
periods, when the appliance has been inactive
for more than 19-hours.
1.3 MODE OF OPERATION
Whenthereisa request forheat and/or hotwater,
via the programmer/time clock and/or any
external control, the pump and fan are started,
thefan speedwillmodulateuntil thecorrectsignal
voltage is received at the control PCB. At this
point an ignition sequence is enabled.
Ignition is sensed by the electronic circuitry to
ensure flame stability at the burner. Once
successful ignition has been achieved, the
electroniccircuitryincreasesthegasrateto75%
fora period of 15 minutes.Thereafter,theboiler’s
output will either be increase to maximum or
modulate to suit the set requirement. When the
appliance reaches the desired temperature the
burner will shut down and the boiler will perform
a three-minute anti-cycle (timer delay).
Whentherequest forheat has been satisfied the
appliancepumpandfan maycontinuetooperate
to dissipate any residual heat within the
appliance.
1.4 SAFETY DEVICES
When the appliance is in use, safe operation is
ensured by:
●a water pressure switch that monitors system
water pressure and will de-activate the pump,
fan and burner should the system water
pressure drop below the rated tolerance.
SECTION 1 DESIGN PRINCIPLE AND OPERATING SEQUENCE
●a high limit thermostat that over-rides the
temperature control circuit to prevent or
interrupt the operation of the burner.
●an analogue pressure switch (PAD) that
checkstheoperationof thefan andfluethereby
allowing safe operation of the burner.
●a sensor that interrupts the operation of the
appliance if the condense pipe becomes
blocked.
●asafetyvalvewhich releases excesspressure
from the primary circuit.
Fig. 2
Flue Outlet Air Intake
AB
Expansion
vessel
Latent Heat
Collector
PAD
AARV
Main Heat
Exchanger
Main
Burner
Gas Valve
Pressure
Switch
Automatyc
by-pass
Safety
valve
Pump
Condense
trap

3
SECTION 2 TECHNICAL DATA
2.1 Central heating Synergy 29
Heat input 29.0 kW
Max heat output 60/80°C (return & flow temp.) 28.1 kW
Max heat output 30/50°C (return & flow temp.) 29.7 kW
Min heat output 60/80°C (return & flow temp.) 9.5 kW
Min heat output 30/50°C (return & flow temp.) 10.2 kW
Minimum working pressure 0.5 bar
Maximum working pressure 3.0 bar
Minimum flow rate 350 l/h
2.2 Gas pressures
Inlet pressure (G20) 20.0 mbar
Burner pressure maximum 9.3 mbar
Burner pressure minimum 1.25 mbar
Maximum gas rate 3.07 Sm3/h
Minimum gas rate 1.05 Sm3/h
Injector size (quantity) 14 x 1.35 mm
2.3 Expansion vessel
Capacity 10-litres
Maximum system volume 91-litres
Pre-charge pressure 1.0 bar
2.4 Dimensions
Height 820mm
Width 450mm
Depth 350mm
Dry weight (kg) 47.0
2.5 Clearances
Sides 12mm
Top 150mm from casing or 25mm above flue elbow (whichever is applicable)
Bottom 150mm
Front 600mm
2.6 Connections
Flow & return 22mm
Hot & cold water 15mm
Gas 15mm
Safety valve 15mm
Condense 21mm
2.7 Electrical
Voltage (V/Hz) 230/50
Power consumption 150W
Internal fuse 2A
External fuse 3A
2.8 Flue details (concentric)
Maximum horizontal flue length (60/100mm) 4.90m
Maximum vertical flue length (60/100mm) 5.70m
Maximum horizontal flue length (80/125mm) 11.80m
Maximum vertical flue length (80/125mm) 13.30m
2.8A Flue Details (twin pipes)
Maximum horizontal flue length (80mm + 80mm) 20m+20m
Maximum vertical flue length (80mm + 80mm) 20m+20m
2.9 Efficiency
SEDBUK (%) 87.6

4
2.10 PUMP DUTY
Fig. 3 shows the flow-rate available - af-
terallowingforpressurelossthroughthe
appliance - for system requirements.
When using this graph, apply only the
pressure loss of the system. The graph
is based on a 20°C temperature differ-
ential.
SECTION 2 TECHNICAL DATA
Fig. 3
Water pressure (mbar)
Litres Per Hour
Appliance Synergy 29
NOx max/min 180/120
CO max/min 100/60
CO2 max/min 6.60/4.15
CO/CO2 ratio max/min 0.00152 to 1/0.00145 to 1
Fig. 4
Key Location Minimum distance
A Below an opening (window, air-brik, etc.) 300 mm
B Above an opening (window, air-brik, etc.) 300 mm
C To the side of an opening (window, air-brik, etc.) 300 mm
D Below gutter, drain-pipe, etc. 75 mm
E Below eaves 200 mm
F Below balcony, car-port roof, etc. 200 mm
G To the side of a soil/drain-pipe, etc. 150 mm
H From internal/external corner or boundary 300 mm
I Above ground, roof, or balcony level 300 mm
J From a surface or boundary facing the terminal 600 mm
K From a terminal facing a terminal 1200 mm
L From an opening in the car-port into the building 1200 mm
M Vertically from a terminal on the same wall 1500 mm
N Horizontally from a terminal on the same wall 300 mm
P From a structure to the side of the vertical terminal 300 mm
Q From the top of the vertical terminal to the roof flashing As determined by the fixed collar
of the vertical terminal
2.11 EMISSIONS
0
0,5
1
1,5
2
2,5
3
3,5
4
4,5
5
5,5
6
6,5
7
0 100 200 300 400 500 600 700 800 900 1000 1100 1200 130
0

5
SECTION 3 GENERAL REQUIREMENTS (UK)
This appliance must be installed by a competent
person in accordance with the Gas Safety
(Installation & Use) Regulations.
3.1 RELATED DOCUMENTS
The installation of this boiler must be in
accordancewiththerelevantrequirementsofthe
Gas Safety (Installation & Use) Regulations, the
localbuildingregulations,thecurrentI.E.E.wiring
regulations, the bylaws of the local water
undertaking, the Building Standards (Scotland)
Regulation and Building Standards (Northern
Ireland) Regulations.
It should be in accordance also with any relevant
requirements of the local authority and the
relevantrecommendations ofthefollowingBritish
Standard Codes of Practice.
3.2 LOCATION OF APPLIANCE
The appliance 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, with
respecttotheinstallationoftheapplianceinaroom
or internal space containing a bath or shower.
When an appliance is installed in a room or
internal space containing a bath or shower, the
appliance or any control pertaining to it must not
be within reach of a person using the bath or
shower.
Thelocationchosen fortheappliancemustpermit
the provision of a safe and satisfactory flue and
termination. The location must also permit an
adequateairsupply forcombustion purposesand
an adequate space for servicing and air
circulation around the appliance. Where the
installation of the appliance will be in an unusual
location special procedures may be necessary,
BS 6798 gives detailed guidance on this aspect.
A compartment used to enclose the appliance
must be designed and constructed specifically
for this purpose. An existing compartment/
cupboard may be utilised provided that it is
modified to suit.
Details of essential features of compartment/
cupboard design including airing cupboard
installationsaregivenin BS 6798.This appliance
is not suitable for external installation.
3.3 GAS SUPPLY
The gas meter - as supplied by the gas supplier
-mustbecheckedtoensurethatitisofadequate
size to deal with the maximum rated input of all
the appliances that it serves. Installation pipes
must be fitted in accordance with BS 6891.
Pipe work from the meter to the appliance must
be of adequate size.Pipes of a smaller size than
the appliance gas inlet connection must not be
used. The installation must be tested for
soundness in accordance with BS6891.
Ifthegas supply serves more thanoneappliance,
it must be ensured that an adequate supply is
maintained to each appliance when they are in
use at the same time.
3.4 FLUE SYSTEM
The terminal should be located where the
dispersal of combustion products is not impeded
and with due regard for the damage and
discoloration that may occur to building products
locatednearby.The terminal mustnotbelocated
in a place where it is likely to cause a nuisance
(see fig. 4).
In cold and/or humid weather, water vapour will
condense on leaving the terminal; the effect of
such pluming must be considered.
If installed less than 2m above a pavement or
platform to which people have access (including
balconies or flat roofs) the terminal must be
protected by a guard of durable material. The
guard must be fitted centrally over the terminal.
Refer to BS 5440 Part 1, when the terminal is
0.5 metres (or less) below plastic guttering or 1
metre (or less) below painted eaves.
3.5 AIR SUPPLY
The following notes are intended for general
guidance only.
Thisapplianceisaroom-sealed,fan-flued boiler,
consequently it does not require a permanent
airventforcombustionairsupply.When installed
in a cupboard or compartment, ventilation for
cooling purposes is also not required.
3.6 WATER CIRCULATION
Detailedrecommendationsaregivenin BS 5449
Part 1 and BS 6798.The following notes are for
general guidance only.
BS 5440 PART 1 FLUES
BS 5440 PART 2 FLUES & VENTILATION
BS 5449 PART 1 FORCED CIRCULATION HOT WATER SYSTEMS
BS 6798 INSTALLATION OF BOILERS OF RATED INPUT NOT EXCEEDING 60kW
BS 6891 LOW PRESSURE INSTALLATION PIPES
BS 7074 PART 1 APPLICATION, SELECTION AND INSTALLTION OF EXPANSION VESSELS AND
ANCILLARY EQUIPMENT FOR SEALED WATER SYSTEMS

6
3.6.1 PIPEWORK
Itisrecommendedthatcoppertubingto BS 2871
Part 1 is used in conjunction with soldered
capillary joints.
Where possible pipes should have a gradient to
ensureairiscarriednaturallyto air releasepoints
and that water flows naturally to drain cocks.
Exceptwhereprovidinguseful heat,pipesshould
be insulated to avoid heat loss and in particular
to avoid the possibility of freezing. Particular
attentionshouldbepaid to pipes passingthrough
ventilated areas such as under floors, loft space
and void areas.
3.6.2 AUTOMATIC BY-PASS
The appliance has a built-in automatic by-pass,
consequently there is no requirement for an
external by-pass, however the design of the
system should be such that it prevents boiler
‘cycling’.
3.6.3 DRAIN COCKS
Thesemustbe located in accessiblepositionsto
facilitate draining of the appliance and all water
pipesconnectedto theappliance.Thedraincocks
must be manufactured in accordance with BS
2879.
3.6.4 AIR RELEASE POINTS
These must be positioned at the highest points
in the system where air is likely to be trapped.
They should be used to expel trapped air and
allow complete filling of the system.
3.6.5 EXPANSIONVESSEL
The appliance has an integral expansion vessel
to accommodate the increased volume of water
when the system is heated. It can accept up to
10 litres of expansion from within the system,
generally this is sufficient, however if the system
has an unusually high water content, it may be
necessary to provide additional expansion
capacity.
3.6.6 FILLING POINT
A method for initial filling of the system and
replacing water lost during servicing etc. is
required (see fig.14).This method of filling must
comply with the current Water Supply (Water
Fittings) Regulations 1999 and Water Bylaws
2000 (Scotland).
3.6.7 LOW PRESSURE SEALED SYSTEM
An alternative method of filling the system would
be from an independent make-up vessel or tank
mounted in a position at least 1 metre above the
highest point in the system and at least 5 metres
above the boiler (see fig. 5). The cold feed from
the make-up vessel or tank must be fitted with
an approved non-return valve and stopcock for
isolation purposes. The feed pipe should be
connectedtothereturn pipeasclosetotheboiler
as possible.
3.6.8 FREQUENT FILLING
Frequent filling or venting of the system may be
indicative of a leak.Care should be taken during
the installation of the appliance to ensure all
aspectsofthe systemarecapable ofwithstanding
pressures up to at least 3 bar.
3.7 ELECTRICAL SUPPLY
The appliance is supplied for operation on 230V
@ 50Hz electrical supply; it must be protected
with a 3-amp fuse.The method of connection to
the mains electricity supply must allow for
completeisolationfromthesupply.Thepreferred
method is by using a double-pole switch with a
contact separation of at least 3mm. The switch
must only supply the appliance and its
corresponding controls, i.e. time clock, room
thermostat, etc. Alternatively an un-switched
shuttered socket with a fused 3-pin plug both
complying with BS 1363 is acceptable.
3.8 MOUNTING ON A COMBUSTIBLE SURFACE
If the appliance is to be fitted on a wall of
combustible material, a sheetoffireproofmaterial
must protect the wall.
3.9 TIMBER FRAMED BUILDINGS
If the appliance is to be fitted in a timber framed
building, it should be fitted in accordance with
the Institute of Gas Engineers publication (IGE/
UP/7) ‘Guide for Gas Installations in Timber
Frame Buildings’.
3.10 INHIBITORS
Vokera recommend that a inhibitor - suitable for
use with low water-content, copper heat
exchangers - is used to protect the boiler and
system from the effects of corrosion and/or
electrolytic action. The inhibitor must be
administered in strict accordance with the
manufacturers* instructions.
*Fernox and Sentinel manufacture products that
have proved suitable for use with Vokera
appliances.Vokera Ltd. cannot comment on the
suitability of any other such product with our
appliances.
Fig. 5
Make-up vessel
or tank
Automatic
air-vent
Non-return
valve Stopcock
5.0 metres minimum
Heating return

7
This appliance must be installed by a competent
person in accordance with and defined by, the
Standard Specification (Domestic Gas
Installations) Declaration (I.S. 813).
3A.1 RELATED DOCUMENTS
The installation of this boiler must be in
accordancewiththerelevantrequirementsofthe
local building regulations, the current ETCI
NationalRulesfor ElectricalInstallations,and the
bylaws of the local water undertaking.
It should be in accordance also with any relevant
requirementsofthelocaland/ordistrictauthority.
3A.2 LOCATION OF APPLIANCE
The appliance may be installed in any room or
internal space, although particular attention is
drawn to the requirements of the current ETCI
NationalRulesfor ElectricalInstallations,andI.S.
813, Annex K.
Whenanapplianceisinstalledinaroomorinternal
space containing a bath or shower, the appliance
or any control pertaining to it must not be within
reach of a person using the bath or shower.
Thelocationchosen fortheappliancemustpermit
the provision of a safe and satisfactory flue and
termination. The location must also permit an
adequate air supply for combustion purposes and
anadequatespacefor servicingandaircirculation
aroundtheappliance.Where theinstallationofthe
appliance will be in an unusual location special
procedures may be necessary, refer to I.S.813 for
detailed guidance on this aspect.
A compartment used to enclose the appliance
must be designed and constructed specifically
for this purpose. An existing compartment/
cupboard may be utilised provided that it is
modified to suit.
This appliance is not suitable for external
installation.
3A.3 GAS SUPPLY
The gas meter - as supplied by the gas supplier
-mustbecheckedtoensurethatitisofadequate
size to deal with the maximum rated input of all
the appliances that it serves. Installation pipes
must be fitted in accordance with I.S.813.
Pipe work from the meter to the appliance must
be of adequate size.Pipes of a smaller size than
the appliance gas inlet connection must not be
used. The installation must be tested for
soundness in accordance with I.S.813.
Ifthegas supply servesmorethanoneappliance,
it must be ensured that an adequate supply is
maintained to each appliance when they are in
use at the same time.
3A.4 FLUE SYSTEM
The terminal should be located where the
dispersal of combustion products is not impeded
and with due regard for the damage and
SECTION 3A GENERAL REQUIREMENTS (EIRE)
discoloration that may occur to building products
locatednearby.The terminal mustnotbelocated
in a place where it is likely to cause a nuisance
(see I.S. 813).
n cold and/or humid weather, water vapour will
condense on leaving the terminal; the effect of
such pluming must be considered.
If installed less than 2m above a pavement or
platform to which people have access (including
balconies or flat roofs) the terminal must be
protected by a guard of durable material. The
guard must be fitted centrally over the terminal.
RefertoI.S.813, when the terminal is 0.5 metres
(or less) below plastic guttering or 1 metre (or
less) below painted eaves.
3A.5 AIR SUPPLY
The following notes are intended for general
guidance only.
Thisapplianceisaroom-sealed,fan-flued boiler,
consequentlyitdoesnotrequire a permanentair
vent for combustion air supply.
When installed in a cupboard or compartment,
ventilation for cooling purposes is also not
required.
3A.6 WATER CIRCULATION
Specific recommendations are given in I.S.813.
Thefollowing notesareforgeneralguidanceonly.
3A.6.1 PIPEWORK
It is recommended that copper tubing be used in
conjunction with soldered capillary joints.
Where possible pipes should have a gradient to
ensureairiscarriednaturallyto air release points
and that water flows naturally to drain cocks.
Exceptwhereprovidingusefulheat,pipes should
be insulated to avoid heat loss and in particular
to avoid the possibility of freezing. Particular
attentionshouldbepaidto pipes passing through
ventilated areas such as under floors, loft space,
and void areas.
3A.6.2 AUTOMATIC BY-PASS
The appliance has a built-in automatic by-pass,
consequently there is no requirement for an
external by-pass, however the design of the
system should be such that it prevents boiler
‘cycling’.
3A.6.3 DRAIN COCKS
These must be located in accessible positions to
facilitate draining of the appliance and all water
pipes connected to the appliance.
3A.6.4 AIR RELEASE POINTS
These must be positioned at the highest points
in the system where air is likely to be trapped.
They should be used to expel trapped air and
allow complete filling of the system.

8
3A.6.5 EXPANSIONVESSEL
The appliance has an integral expansion vessel
to accommodate the increased volume of water
when the system is heated. It can accept up to
10 litres of expansion from within the system,
generallythisis sufficient,howeverifthesystem
has an unusually high water content, it may be
necessary to provide additional expansion
capacity.
3A.6.6 FILLING POINT
A method for initial filling of the system and
replacing water lost during servicing etc. is
required (see fig. 14). You should ensure this
method of filling complies with the local water
authority regulations.
3A.6.7 LOW PRESSURE SEALED SYSTEM
An alternative method of filling the system would
be from an independent make-up vessel or tank
mounted in a position at least 1 metre above the
highest point in the system and at least 5 metres
above the boiler (see fig.5).
The cold feed from the make-up vessel or tank
must be fitted with an approved non-return valve
and stopcock for isolation purposes. The feed
pipe should be connected to the return pipe as
close to the boiler as possible.
3A.6.8 FREQUENT FILLING
Frequent filling or venting of the system may be
indicative of a leak.Care should be taken during
the installation of the appliance to ensure all
aspectsofthe systemarecapable ofwithstanding
pressures up to at least 3 bar.
3A.7 ELECTRICAL SUPPLY
The appliance is supplied for operation on 230V
@ 50Hz electrical supply; it must be protected
with a 3-amp fuse.The method of connection to
the mains electricity supply must allow for
completeisolationfromthesupply.Thepreferred
method is by using a double-pole switch with a
contact separation of at least 3mm. The switch
must only supply the appliance and its
corresponding controls, i.e. time clock, room
thermostat, etc.
3A.8 MOUNTING ON A COMBUSTIBLE SURFACE
If the appliance is to be fitted on a wall of
combustible material, a sheetoffireproofmaterial
must protect the wall.
3A.9 TIMBER FRAMED BUILDINGS
If the appliance is to be fitted in a timber framed
building, it should be fitted in accordance with
I.S.813 and local Building Regulations.
The Institute of Gas Engineers publication (IGE/
UP/7) ‘Guide for Gas Installations in Timber
FrameBuildings’givesspecificadviceonthis type
of installation.
3A.10 INHIBITORS
Vokera recommend that a inhibitor - suitable for
use with low water-content, copper heat
exchangers - is used to protect the boiler and
system from the effects of corrosion and/or
electrolytic action. The inhibitor must be
administered in strict accordance with the
manufacturers* instructions.
*Fernox and Sentinel manufacture products that
have proved suitable for use with Vokera
appliances.Vokera Ltd. cannot comment on the
suitability of any other such product with our
appliances.
3A.11 DECLARATION OF CONFORMITY
A Declaration of Conformity (as defined in I.S.
813) must be provided on completion of the
installation.
A copy of the declaration must be given to the
responsible person and also to the gas supplier
if required.

9
SECTION 4 INSTALLATION
4.1 DELIVERY
Due to the weight of the appliance it may be
necessary for two people to lift and attach the
appliance to its mounting. The appliance is
contained within a heavy-duty cardboard carton.
Lay the carton on the floor with the writing the
correct way up.
4.2 CONTENTS
Contained within the carton is:
●the boiler
●the wall bracket
●template
●an accessories pack containing appliance
service connections and washers
●the instruction pack containing the installation
& servicing instructions, user instructions,
Benchmark logbook, guarantee registration
card and a 3-amp fuse.
4.3 UNPACKING (see fig. 6)
At the top of the carton pull both sides open – do
not use a knife – unfold the rest of the carton
from around the appliance, carefully remove all
protective packaging from the appliance and lay
theaccessoriesetc.to oneside.Protectivegloves
shouldbeusedtolift the appliance,theappliance
back-frame should be used for lifting points.
4.4 PREPARATION FOR MOUNTING THE
APPLIANCE (see fig. 6A)
The appliance should be mounted on a smooth,
vertical,non-combustiblesurface, which mustbe
capable of supporting the full weight of the
appliance. Care should be exercised when
determining the position of the appliance with
respect to hidden obstructions such as pipes,
cables, etc.
When the position of the appliance has been
decided - using the template supplied – carefully
mark the position of the wall- mounting bracket
(see fig. 6A) and flue-hole (if applicable).
4.5 FITTINGTHE FLUE
The top flue outlet permits both horizontal and
vertical flue applications to be considered,
alternatively, the Vokera twin flue system can be
utilised if longer flue runs are required.
4.5.1 CONCENTRIC HORIZONTAL FLUE
(For concentric vertical flue, see 4.5.2)
(For twin flue applications, see 4.5.3)
Theappliancecanbeusedwith either theVokera
condensing60/100mmconcentric flue systemor
the optional 80/125mm concentric flue system.
NOTE
These instructions relate only to the Vokera
condensing 60/100mm concentric flue system.
For specific details on the installation of the 80/
125mm concentric flue system please refer to
the instructions supplied.
The appliance flue outlet elbow can be rotated
through 360°on its vertical axis. In addition the
flue may be extended from the outlet elbow in
the horizontal plane (see 2.8). A reduction must
also be made to the maximum length (see table
below) when additional bends are used.
Fig. 6
Fig. 6A
523
115
145
200
820
150
107.5
85 35
453
CONDENSATE
PIPE
RETURN FLOW GAS

10
Horizontal flue terminals and accessories
Part No. Description Min-Max Length
0225720 Horizontal flue kit for use 1000mm
with add. bends &
extensions
0225755 Telescopic extension 350mm – 500mm
0225740 0.5m extension 500mm
0225745 1.0m extension 1000mm
0225750 2.0m extension 2000mm
0225730 45°bend (pair) N/A
0225735 90°bend N/A
0225760 Wall bracket (5) N/A
Bend Reductionin maximumfluelength foreachbend
45°bend 0.5 metre
90°bend 1.0 metre
Reduction for additional bends
Using the template provided, mark and drill a
115mmholeforthepassageoftheflue pipe.The
hole should have a 1°rise from the boiler to
outside,toensureanycondense fluid that forms,
is allowed to drain back to the appliance.
The fixing holes for the wall-mounting bracket
should now be drilled and plugged, an
appropriate type and quantity of fixing should be
used to ensure that the bracket is mounted
securely. Once the bracket has been secured to
the wall, mount the appliance onto the bracket.
FITTINGTHE HORIZONTAL FLUE KIT
Carefully measure the distance from the centre
of the appliance flue outlet to the edge of the
finished outside wall (dimension X). Add 45mm
to dimension X to give you DimensionY (see fig
7A).Measure dimensionY from the terminal end
of the concentric flue pipe and cut off the excess
ensuring any burrs are removed. Pass the
concentric flue pipethroughthepreviously drilled
hole.Fit the flue bend to the boiler flue outlet and
insert the concentric flue pipe into the flue bend
ensuring the correct seal is made. Using the
clamp, gasket and screws supplied, secure the
flue bend to the appliance flue spigot.The 60mm
M & F adaptor (supplied with the flue kit) should
be discarded.
NOTE
Fit the internal trim to the flue assembly prior to
connecting the flue pipe to the bend.
You must ensure that the entire flue system is
properly supported and connected.
Seal the flue assembly to the wall using cement
or a suitable alternative that will provide
satisfactory weatherproofing.
The exterior trim can now be fitted.
4.5.1.1 EXTENDINGTHE FLUE
Connect the bend - supplied with the terminal kit
- to the top of the boiler using clamp (supplied)
seefig.7.Theadditionalbends& extensionshave
push-fit connections, care should be taken to
ensure that the correct seal is made when
assemblingthefluesystem.Connecttherequired
number of flue extensions or bends (up to the
maximum equivalent flue length) to the flue
terminal (see fig. 7 & 8).
The hole should have a 1°rise from the boiler to
outside, to ensure anycondensefluidthatforms,
is allowed to drain back to the appliance.
NOTE
Whencuttinganextension to therequiredlength,
you must ensure that the excess is cut from the
plain end of the extension (see fig. 7 & 8).
Remove any burrs, and check that all seals are
located properly.
You must ensure that the entire flue system is
properly supported and connecte.
Seal the flue assembly to the wall using cement
or a suitable alternative that will provide
satisfactory weatherproofing. The interior and
exterior trim can now be fitted.
Fig. 7A
Fig. 7 Boiler
Push-fit connection
Terminal or
extension
outer
clamp
125mm
“Y” = “X” + 45mm

11
4.5.2 CONCENTRIC VERTICAL FLUE
Theappliancecanbeusedwith either theVokera
condensing60/100mmconcentric flue systemor
the optional 80/125mm concentric flue system.
NOTE
These instructions relate only to the Vokera
condensing 60/100mm concentric flue system.
For specific details on the installation of the 80/
125mm concentric flue system please refer to
the instructions supplied.
The vertical flue terminal can be connected
directly to the appliance flue outlet.Alternatively,
an extension or bend can be connected to the
appliance flue outlet if desired, however if
additional bends are fitted, a reduction must be
made to the maximum flue length (see table
below).
Bend Reduction in maximum flue length for each bend
45°bend 0.5 metre
90°bend 1.0 metre
Vertical flue terminal and accessories
Part No. Description Length
0225725 Vertical flue terminal 1.0 metre
0225770 Pitched roof flashing plate N/A
0225765 Flat roof flashing plate N/A
0225755 350-500 telescopic extension 350mm – 500mm
0225740 500mm extension 500mm
0225745 1000mm extension 1000mm
0225750 2000mm extension 2000mm
0225730 45°bend (pair) N/A
0225735 90°bend N/A
0225760 Wall bracket (4) N/A
Reduction for bends
Usingthe dimensions giveninfig.9 asareference,mark
and cut a 115mm hole in the ceiling and/or roof.
Fit the appropriate flashing plate to the roof and insert
the vertical flue terminal through the flashing plate from
the outside, ensuring that the collar on the flue terminal
fits over the flashing.
Thefixingholesforthewall-mounting bracketshouldnow
be drilled and plugged, an appropriate type and quantity
of fixing should be used to ensure that the bracket is
mounted securely. Once the bracket has been secured
to the wall, mount the appliance onto the bracket.
Fig. 9
IMPORTANT
The vertical flue terminal is 1.0 metre in length
andcannotbecut;therefore it maybenecessary
to adjust the height of the appliance to suit or
use a suitable extension.
Connect the vertical flue assembly to the boiler
flue spigot using the 60mm & 100mm clips,
gaskets&screws(supplied), ensuringthecorrect
seal is made.The flue support bracket (supplied
with the vertical flue kit) can now be fitted.
If the vertical flue requires extension/s or
additional bend/s, connect the required number
of flue extensions or bends (up to the maximum
equivalent flue length) between the boiler and
vertical flue assembly (see fig.8).
Ensure that any horizontal sections of the flue
system have a 1°fall back to the boiler (17mm
per 1000mm).
Fig. 8

12
Bend Reduction in maximum flue length for each bend
45°bend 1.0 metre
90°bend 1.0 metre
Reduction for bends
Part No. Description Length
0225805 Horizontal flue terminal 1.0 metre
0225810 Vertical flue terminal 1.0 metre
359 Twin adapter kit N/A
0225770 Pitched roof flashing plate N/A
0225765 Flat roof flashing plate N/A
0225815 Condensate drain kit N/A
0225820 0.25m extension (pair) 250mm
0225825 0.5m extension (pair) 500mm
0225830 1.0m extension (pair) 1000mm
0225835 2.0m extension (pair) 2000mm
0225840 45°bend (pair) N/A
0225845 90°bend (pair) N/A
0225850 Twin bracket (5) N/A
0225855 Single bracket (5) N/A
Twin flue accessories
MOUNTINGTHE BOILER
Thefixingholesforthewall-mountingbracketshouldnow
be drilled and plugged, an appropriate type and quantity
of fixing should be used to ensure that the bracket is
mounted securely. Once the bracket has been secured
to the wall, mount the appliance onto the bracket.
Pay attention to condense trap!
4.5.3.1 INSTALLATION OF TWIN ADAPTOR KIT (see
fig. 10 & 11)
●Insert the exhaust connection manifold (A)
onto the appliance flue outlet.
●Remove the blankingplate(located to the right
of the appliance flue outlet) and - using the
same screws - install the air inlet plate (B).
●Using the hole in the exhaust connection
manifold as a guide, drill a 3mm hole in the
appliance flue spigot and secure the exhaust
manifold connection to the flue spigot using
the screw provided (C).
●Using the two holes in the air inlet plate as a
guide,drill a 3mm hole in eachandsecurethe
air inlet pipe/bend using the screws provided.
●Thetwinflue pipesextensionsandaccessories
can now be installed by pushing together (the
plain end of each extension or bend should
be pushed approximately 50mm into the
female socket of the previous piece).
NOTE
Whencuttinganextensiontotherequiredlength,
you must ensure that the excess is cut from the
plain end of the extension (see fig. 8). Remove
any burrs and check that any seals are located
properly.
You must ensure that the entire flue system is
properly supported and connected.
4.5.3 TWIN FLUE SYSTEM
TheVokeratwinfluesystemenablesgreater flue
distances to be achieved (see 4.4.2) than that of
a concentric flue system. It can be used for
horizontal or vertical applications, however the
twin flue system must be converted to the
dedicated concentric flue kit for termination. It is
essential that the installation of the twin flue
system be carried out in strict accordance with
these instructions.
GUIDANCE NOTES ON TWIN FLUE INSTAL-
LATION
●The flue must have a fall back of 1°back to
the appliance to allow any condensate that
may form in the flue system to drain via the
condensatedrain.Consideration mustalsobe
given to the fact that there is the possibility of
a small amount of condensate dripping from
the terminal.
●Ensure that the entire flue system is
adequatelysupported,useat leastonebracket
for each extension.
●The entire flue system must be adequately
insulated to maintain heat within the flue
system thereby reducing the possibility of
condensate production.
●Astheexhaust outlet pipe can reach veryhigh
temperatures it must be protected to prevent
persons touching the hot surface.
●Thecondensatedrainpipe mustbeconnected
in accordance with building regulations.
Fig. 10
C
AB
Fig. 11

13
4.5.3.2 HORIZONTALTERMINATION (see fig. 12)
The twin flue system must be converted to the
dedicated concentric flue kit for termination.
●Thehorizontalterminal is supplied with a built-
in converter box and cannot be shortened.
●A 130mm hole is required for the passage of
the concentric terminal through the wall.
●The air inlet pipe must always be level with or
below, that of the exhaust pipe.
Dependingonsiteconditions it maybe preferable
to install the terminal assembly prior to fitting the
twin flue pipes.
Mark and drill a 130mm hole for the passage of
the horizontal flue terminal, ensuring that there
isa1°fall backtothe boiler (17mmper1000mm).
Insert the terminal assembly into the flue hole.
Push-fitthe twin flue pipes onto the concentricto
twinconverter boxensuring thattheexhaust pipe
connects to the exhaust connection on the
concentric to twin converter.
If necessary cut the plain ends (male) of the twin
flue pipes to allow connection to the concentric
to twin converter
NOTE
Before cutting twin flue pipes ensure allowances
have beenmadeforconnectionontothe previous
piece and onto the concentric to twin converter.
The last twin flue pipes must be pushed 50mm
onto the male spigots of the concentric to twin
converter.
NOTE
You must ensure that the entire flue system is
properly supported and connected.
Seal the flue terminal assembly to the wall using
cement or a suitable alternative that will provide
satisfactory weatherproofing. The interior and
exterior trim can now be fitted.
Fig. 12
4.5.3.3 VERTICAL TERMINATION (see fig. 13)
The twin flue system must be converted to the
dedicated concentric flue kit for termination.
●The vertical terminal is supplied with a built-in
converter box and cannot be shortened.
●A 130mm hole is required for the passage of
theconcentric terminal through theceilingand/
or roof.
Dependingonsiteconditions it may be preferable
to install the terminal assembly prior to fitting the
twin flue pipes.
Fit the appropriate flashing plate to the roof and
insert the vertical flue terminal through the
flashing plate from the outside, ensuring that the
collar on the flue terminal fits over the flashing.
Push-fitthe twin flue pipes onto the concentricto
twin converter ensuring that the exhaust pipe
connects to the exhaust connection on the
concentric to twin converter.
If necessary cut the plain ends (male) of the twin
flue pipes to allow connection to the concentric
to twin converter.
NOTE
●Before cutting twin flue pipes ensure
allowances have been made for connection
onto the previous piece and onto the
concentric to twin converter.The last twin flue
pipes must be pushed 50mm onto the male
spigots of the concentric to twin converter.
●You must ensure that the entire flue system is
properly supported and connected.
●Ensure that any horizontal sections of pipe
have a 1°alltowardstheappliance(17mmper
1000mm).
1.0-metre
1-deg. = 17mm

14
4.6 CONNECTINGTHE GAS AND WATER
Theapplianceissuppliedwith servicevalves (fig.
14). The service valves are of the compression
type. The accessories pack contains sealing
washers etc, for use with the service valves.
Whenconnectingpipeworktothevalves, tighten
the compression end first then insert the sealing
washers before tightening the valve to the
appliance.
NOTE
It will be necessary to hold the valve with one
spanner whilst tightening with another.
Fig. 14
4.6.1 GAS (see fig. 6A & 14)
The appliance is supplied with a 15mm service
valve, connect a 15mm pipe to the inlet of the
valve and tighten both nuts.
NOTE
It will be necessary to calculate the diameter of
the gas supply pipe to ensure the appliance has
an adequate supply of gas.
4.6.2 FLOW & RETURN (see fig. 6A & 14)
The appliance is supplied with 22mm service
valves for the flow and return connections,
connect a 22mm pipe to the inlet of each valve
and tighten both nuts.
NOTE
Depending on system requirements, it may
necessary to increasethesizeofthe flow&return
pipe work after the service valve connections.
4.6.3 SAFETY VALVE (see fig. 6A & 14)
Connect the safety valve connection pipe to the
safety valve outlet. Connect a discharge pipe to
the other end of the safety valve connection pipe
and tighten. The discharge pipe must have a
continuousfallawayfromtheappliance tooutside
and allow any water to drain away thereby
eliminating the possibility of freezing. The
dischargepipemustterminate inapositionwhere
any water – possibly boiling – discharges safely
without causing damage or injury, but is still
visible.
Fig. 13
Control valve
Flow pipe
Temporary
connection
Control
valve
Double
check valve Supply

15
4.6.4 CONDENSE PIPE
During normal operation the boiler produces
condense which is collected in a trap located in
the lower part of the boiler. A flexible pipe
(condense outlet pipe) is connected to the outlet
of the trap.The flexible pipe must be connected
to a plastic waste pipe only. The plastic waste
pipe must have a minimum of a 3°fall towards
the drain. Any external run of pipe should be
insulated to prevent the risk of freezing.
CONNECTINGTHE CONDENSATE OUTLET
Gently pull the condense outlet pipe down from
its location inside the boiler until approximately
200mmprotrudesfromtheundersideoftheboiler.
Connect a suitable plastic (not copper) pipe (no
less than 20mm diameter) to the outlet pipe and
ensure it discharges in accordance with building
regulations or other rules in force.
4.7 ELECTRICAL CONNECTIONS
The electrical supply must be as specified in
section 3/3A. A qualified electrician should
connect the electrical supply to the appliance. If
controls-externaltotheappliance-arerequired,
a competent person must undertake the design
of any external electrical circuits, please refer to
section 8 for detailed instructions. ANY
EXTERNAL CONTROL OR WIRING MUST BE
SERVED FROM THE SAME ISOLATOR AS
THAT OF THE APPLIANCE. The supply cable
from the isolator to the appliance must be 3-core
flexible sized 0.75mm to BS 6500 or equivalent.
Wiring to the appliance must be rated for
operation in contact with surfaces up to 90°C.
4.7.1 CASING REMOVAL
Togaininternal accesstotheapplianceyoumust
first remove the casing, proceed as outlined
below:
●pressthecontrolscoverto release the controls
cover catch
●locate and unscrew the 2 screws that secure
thecontrolsfasciatotheappliancecasing (see
fig. 15)
●gently lower the control fascia until it rests
●remove the2screwslocatedatthe Left&Right
of the underside of the casing
●lift the casing upward to disengage it from the
top locating hooks and then remove
●store the casing and screws safely until
required. Re-fit in the reverse order.
4.7.2 APPLIANCETERMINAL BLOCK
The appliance terminal block is located on the
left side of the control fascia (see fig.15).Locate
and remove the screws securing the terminal
block cover.
NOTE
The appliance comes with a factory fitted link to
allow basic operation of the boiler via the mode
selector switch. If it is anticipated that external
controls will be required please refer to the wiring
diagramsinsection8formoredetailedinformation.
Fig. 15
4.7.3 CONNECTINGTHE MAINS (230V) INPUT (see
fig. 16)
Remove the terminal block cover as described
in 4.7.2. Pass the cable through the cable
anchorage (see fig. 16). On the terminal block
there are 7 terminals from Right to Left they are:
1. LIVE
2. NEUTRAL
3. 230V output
4. 230V input
5. (spare)
6. (spare)
7. (spare)
8. (spare)
Connect the supply cable wires (LIVE and
NEUTRAL) to their corresponding terminals on
theapplianceterminalblock.ConnecttheEARTH
wire to the EARTH block (see fig. 16) ensuring
that it’s left slightly longer that the others, this will
prevent strain on the EARTH wire should the
cable become taut.
Do not remove the link wire (between 3 & 4)
unlessadditionalexternalcontrolsaretobefitted
(seesection8).Re-fitthe applianceterminal block
cover.
The securing screw on the cable anchorage
should now be tightened. This must be done
before the control fascia is re-fitted in the upright
position. The appliance casing and screws can
now be re-fitted.
A

16
Connect the supply cable wires (LIVE and
NEUTRAL) to their corresponding terminals on
theapplianceterminalblock.ConnecttheEARTH
wire to the EARTH block (see fig. 16) ensuring
that it’s left slightly longer that the others, this will
prevent strain on the EARTH wire should the
cable become taut.
Fig. 16

17
5.1 GAS SUPPLY INSTALLATION
Inspect the entire installation including the gas
meter, test forsoundness and purge.Refer to BS
6891 for specific instruction.
5.2 THE HEATING SYSTEM
The appliance contains components that may
becomedamagedorrenderedinoperablebyoils
and/or debris that are residual from the
installation of the system, consequently it is
essential that the system be flushed in
accordance with the following instructions.
5.3 INITIAL FILLING OFTHE SYSTEM
Ensure both flow and return service valves are
open, remove appliance casing as described in
4.7.1,identifytheautomaticairreleasevalveand
loosen the dust cap by turning the cap anti-
clockwise one full turn. IMPORTANT, THERE
ARE NO MANUAL AIR RELEASE VALVES
LOCATED ON THE APPLIANCE. Ensure all
manual air release valves located on the heating
system are closed. Using the approved method
offilling(fig.14), slowlyproceedtofillthesystem,
as water enters the system the pressure gauge
will begin to rise.Once the gauge has reached 1
bar close both the inlet and service valves and
begin venting all manual air release valves,
starting at the lowest first. It may be necessary
togoback and top-upthepressureuntiltheentire
system has been filled. Inspect the system for
water soundness, rectifying any leaks.
5.4 INITIAL FLUSHING
Thewholeoftheheatingsystemmustbe flushed
both cold and hot as detailed in 5.8. Open all
radiator or heating valves and the appliance flow
& return service valves. Drain the boiler and
system from the lowest points. Open the drain
valve full bore to remove any installation debris
from the boiler prior to lighting. Refill the boiler
and heating system as described in 5.3.
5.5 PRE-OPERATION CHECKS
Before attempting the initial lighting of the
appliance, the following checks must be carried
out:
●ensure all gas service valves from the meter
to the appliance are open and the supply pipe
has been properly purged
●ensuretheproperelectricalcheckshavebeen
carried out, (see 7.7) particularly continuity,
polarity and resistance to earth
●ensure the 3 amp fuse - supplied with the
appliance - has been fitted
●ensurethesystemhasbeen filled, ventedand
the pressure set to 1 bar
●ensuretheflue system hasbeenfittedproperly
and in accordance with the instructions
●ensure all appliance service valves are open.
SECTION 5 COMMISSIONING
5.6 INITIAL LIGHTING
Ensure the electrical supply to the appliance is
switched on.Move the selector switch to the ON
position, ensure any time clock or programmer
is switched to an ‘ON’ position and ensure any
other external controls are also calling for heat.
The appliance will now operate in the heating
mode as described in 1.3. Should the appliance
fail to ignite, refer to 5.5 and/or section 7
(faultfinding).
5.7 CHECKINGTHE BURNER PRESSURE
Although the burner pressure is factory set, it is
necessary to check it during commissioning.
Isolate the appliance from the electrical supply
andattachasuitablemanometertothegasvalve
outlet test-point (see fig. 17). Light the boiler as
described in 5.6, allowing the appliance to
stabilise.Comparethereadingon themanometer
with the value described in 2.3. If adjustment is
required,followthedetailed instructions insection
7 (7.3).
Once the burner pressure has been checked,
isolate the appliance from the electrical supply,
remove the manometer andtightenthegasvalve
outlet test nipple.
5.8 FINAL FLUSHING OFTHE HEATING SYSTEM
The system shall be flushed in accordance with
BS 7593. If a cleanser is to be used, it shall be
from a reputable manufacturer* and shall be
administered in strict accordance with the
manufacturers instructions.
*BothSentinelandFernoxmanufactureproducts
that have proved suitable for use with Vokera
appliances.Vokera Ltd. cannot comment on the
suitability of any other such product with our
appliances.
Fig. 17
Protective
cap
Outlet
test-point
Inlet
test-point

18
5.8.1 INHIBITORS
See Section 3 “General requirements”.
5.9 SETTING THE BOILER OPERATING TEM-
PERATURE
The flow outlet temperature can be adjusted
between 40°C - 80°C via the thermostat knob
(see fig.1).
5.10 SETTINGTHE SYSTEM DESIGN PRESSURE
The design pressure should be a minimum of 1
bar and a maximum of 1.5 bar.
The actual reading should ideally be 1 bar plus
theequivalentheightin metres(0.1bar= 1metre)
tothehighestpointinthesystemabove the base
of the appliance (up to the maximum of 1.5 bar
total).
N.B. The safety valve is set to lift at 3 bar/30
metres/45 psig.
To lower the system pressure to the required
value, pull lever onheadofsafetyvalve to release
water until the required figure registers on the
pressure gauge (see fig. 1).
5.11 REGULATING THE CENTRAL HEATING
SYSTEM
Fully open all radiator and circuit valves and run
theapplianceforbothheating and hot wateruntil
heatedwateris circulating.Ifconditions are warm
remove any thermostatic heads. Adjust radiator
returnvalvesandanybranchcircuitreturn valves
untiltheindividual returntemperaturesarecorrect
and are approximately equal.
5.12 FINAL CHECKS
●ENSURE ALL TEST NIPPLES ON THE
APPLIANCE GAS VALVE HAVE BEN
TIGHTENED AND CHECKED FOR
SOUNDNESS
●ENSURE THE APPLIANCE FLUE SYSTEM
ISFITTEDCORRECTLY AND IS PROPERLY
SECURED
●ENSUREALLPIPEWORKISRE-CHECKED
FOR SOUNDNESS
●RE-FIT APPLIANCE CASING
●COMPLETE APPLIANCE LOGBOOK.
Complete details of the boiler, controls,
installation and commissioning in the logbook
supplied with the boiler. This is an important
document, which must be correctly completed
and handed to the user. Failure to install and
commission the appliance to the manufacturers
instructions may invalidate the warranty.
5.13 INSTRUCTINGTHE USER
Hand over all documentation supplied with this
appliance - including these instructions - and
explain the importance of keeping them in a safe
place.
Explain to the user how to isolate the appliance
from the gas, water and electricity supplies and
the locations of all drain points.
Show the user how to operate the appliance and
any associated controls correctly.
Showtheuserthelocationofthefillingvalveand
how to top-up the system pressure correctly and
showthe location ofallmanualairrelease points.
Explain to the user how to turn off the appliance
for both long and short periods and advise on
the necessary precautions to prevent frost
damage.
Explain to the user that for continued safe and
efficient operation, the appliance must be
serviced annually by a competent person.