VOKERA Syntesi e Release note

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Installation
& Servicing
Instructions
THESE INSTRUCTIONS
TO BE RETAINED
BY USER

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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 (Heating) 2
1.4 Mode of operation (DHW) 2
1.5 Safety devices 2
1.6 Optional accessories 2
Technical data Page
2.1 Central heating 3
2.2 Domestic hot water 3
2.3 Gas pressure 3
2.4 Expansion vessel 3
2.5 Dimensions 3
2.6 Clearances 3
2.7 Connections 3
2.8 Electrical 3
2.9 Flue details (concentric) 3
2.9A Flue details (twin pipes) 3
2.10 Efficiency 3
2.11 Pump duty 4
2.12 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 6
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 Showers 6
3.9 Mounting on a combustible surface 6
3.10 Timber framed building 7
3.11 Inhibitors 7
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 8
3.A6.1 Pipework 8
3.A6.2 Automatic by-pass 8
3.A6.3 Drain cocks 8
3.A6.4 Air release points 8
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 Showers 8
3.A9 Mounting on a combustible surface 8
3.A10 Timber framed building 8
3.A11 Inhibitors 8
3.A12 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 Cold water inlet 14
4.6.4 Hot water outlet 14
4.6.5 Safetyvalve 14
4.6.6 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
4.7.4 Connecting the Vokera time clock 16
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 Filling the hot water system 17
5.6 Pre-operation checks 17
5.7 Initial lighting 17
5.7.1 Checking burner pressures 17
5.8 Final flushing of the heating system 18
5.8.1 Inhibtors 18
5.9 Setting the boiler operating temperature 18
5.9.1 Setting the domestic hot water temperature 18
5.10 Setting the system design pressure 18
5.11 Regulating the hot water 18
5.11.1 Changing the flow restrictor 18
5.11.2 Regulating the central heating system 18
5.12 Final checks 18
5.13 Instructing the user 19
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 Safetyvalve 20
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 21
6.12 Printed circuit board 21
6.13 Gas valve 21
6.14 Integral time switch 22
6.15 Electrode, burner thermostat, burner & injectors 22
6.16 Flue fan 23
6.17 Main heat exchanger 23
6.18 Air pressure switch 24
6.19 Flow restrictor 24
6.20 DHW flow switch 24
6.21 DHW heat exchanger 24
6.22 Valve actuator 24
6.23 Divertor valve assembly 24
6.24 Secondary thermistor 25
6.25 Automatic by-pass 25
6.26 DHW non-return valve 25
6.27 Expansion vessel 25
6.27.1 Expansion vessel removal 25
6.27.2 Expansion vessel removal 25
6.28 Latent heat collector 26
6.28A Dismantling the latent heat collector 26
6.29 Condense trap removal 26
Checks, adjustments and fault finding page
7.1 Checking appliance operation 27
7.2 Appliance mode of operation 27
7.2.1 Selector switch in the off position 27
7.2.2 Selector switch in the hot water only position 27
7.2.3 Selector switch in the heating & hot water position 27
7.2.4 Appliance functions 27
7.2.5 Heating mode 27
7.2.6 DHW mode 28
7.3 Checking and adjusting burner pressure 28
7.3.1 Setting the maximum burner pressure 28
7.3.2 Setting the minimum burner pressure 28
7.4 Combustion analysis test 28
7.5 Checking the expansion vessel 29
7.6 External faults 29
7.6.1 Installation faults 29
7.7 Electrical checks 29
7.7.1 Earth continuity test 29
7.7.2 Short circuit test 29
7.7.3 Polarity check 29
7.7.4 Reversed polarity or supply fault 29
7.7.5 Resistance to earth check 30
7.8 Fault finding 30
7.9 Fault codes 31-38
Wiring diagrams Page
8.1 External wiring 39
8.2 Typical control applications 39
8.3 Vokera time clock 39
8.4 Vokera remote control 39
8.5 Vokera room thermostat 39
8.6 Other controls 39
Exploded diagrams Page
Table 1 - 5 43 - 48
L.P.G. instructions Page
10.1 Related documents 49
10.2 Technical data 49
10.3 Converting the appliance gas type 49
10.4 Gas supply 49
10.5 Gas supply installation 49
10.6 Checking and adjusting burner pressure 49
10.6.1 Setting the maximum burner pressure 49
10.6.2 Setting the minimum burner pressure 49

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TheSyntesirangeofappliancesiscomprisedof3models
of high-efficiency combination boiler with outputs to
heating & DHW of 24, 28, & 34kW respectively. Each
appliance – by design – incorporates electronic ignition,
circulatingpump,expansionvessel,safetyvalve, pressure
gauge, and automatic by-pass.
TheSyntesi range isproduced as roomsealed, category
II2H3+ appliances, suitable for internal wall mounting
applications only. They are provided with a fan powered
flue outlet with an annular co-axial combustion air intake
INTRODUCTION
that can be rotated – horizontally – through 360 degrees
forvarioushorizontalor vertical applications. The Syntesi
rangecan also beused with theVokera twin fluesystem.
The Syntesi range is approved for use with C12 & C32
type flue applications.
These appliances are designed for use with a sealed
system only; consequently they are not intended for use
on open vented systems.
Fig. 1
Fig.1 General Layout
1 SafetyValve
2 Pressure Switch
3 Diverter Valve Motor
4 Domestic Heat Exchanger
5 Pump
6 AutomaticAir Release Valve
7 Main Burner
8 Electrode
9 Main Heat Exchanger
10 Latent Heat Collector
11 Condense Sensor
12 Flue GasAnalysis Test Point
13 Flue Outlet
14 Air Intake
15 Differential Analog Pressure Switch
16 Silicone PressureTube
17 Silicone Negative PressureTube
18 FanAssembly
19 Combustion Chamber
20 Burner Temperature Control
21 ExpansionVessel
22 Transformer
23 GasValve
24 Modulator Coil
25 CondenseTrap
26 Domestic Hot Water Flow Switch
27 Hot Water Temperature Control
28 Mode Selector Switch
29 Status LED
30 Temperature Indicator
31 DHW Request LED
32 Central Heating Temperature Control
33 Combustion Switch
34 Timeclock Aperture (optional)
35 Pressure Gauge
6
9
11 12 13 14
19
22
24
15
16
17
23
18
1
2
3
4
5
7
8
10
20
21
25
26
35 34 33
27 28 30 3129 32

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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
●Safetyvalve
1.2 MODE OF OPERATION (at rest)
When the appliance is at rest and there are no
requests for heating or DHW, the following func-
tions are active:
●pre-heat function – the pre-heat function ena-
blestheappliancetoperiodicallylightandmain-
tain the temperature of the DHW heat ex-
changer. This “keep-hot” facility enables the
appliance to provide an instantaneous re-
sponse to DHW requests.
●2-stagefrost-protection system –the frost-pro-
tection system protects the appliance against
the risk of frost damage. The first stage ena-
blesactivationofthepumpshouldthetempera-
ture of the appliance fall to 7°C. The second
stage becomes active when the temperature
has dropped to 3°C. Should the second stage
become active, the appliance will function on
minimum power until it reaches 30°C.
●anti-blockfunction–theanti-blockfunctionena-
bles the pump and divertor valve actuator, to
be energised for short periods, when the ap-
pliance has been inactive for more than 19-
hours.
1.3 MODE OF OPERATION (Heating)
When there is a request for heat via the
programmer/time clock and/or any external
control, the pump and fan are started, the fan
speed will modulate until the correct signal
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
electroniccircuitry increases the gas rateto 75%
foraperiodof 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).
Whenthe request for heat hasbeen satisfied the
appliancepumpand fan maycontinueto operate
to dissipate any residual heat within the
appliance.
1.4 MODE OF OPERATION (DHW)
When there is a request for DHW via a hot water
outlet or tap, the pump and fan are started, the
fan speed will modulate until the correct signal
voltage is received at the control PCB. At this
point an ignition sequence is enabled.
During DHW request LED (31, fig. 1) is ON.
Ignition is sensed by the electronic circuitry to
ensure flame stability at the burner. Once
SECTION 1 DESIGN PRINCIPLES AND OPERATING SEQUENCE
successful ignition has been achieved, the
electronic circuitry increases the gas rate to
maximum or will modulate output to stabilise the
temperature. In the event of the appliance
exceedingthedesiredtemperaturetheburnerwill
shut down until the temperature drops.
When the request for DHW has been satisfied
the appliance pump and fan may continue to
operate to dissipate any residual heat within the
appliance.
1.5 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.
●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
checkstheoperationofthefanandflue thereby
allowing safe operation of the burner.
●a sensor that interrupts the operation of the
appliance if the condense pipe becomes
blocked.
●asafetyvalvewhich releases excess pressure
from the primary circuit.
1.6 OPTIONAL ACCESSORIES
The Syntesi is suitable for use with a range of
optional accessories that enable enhanced
operation and/or applications. These include:
●RC05 remote control – the RC05 remote
controlenables the appliance tobe controlled,
adjusted,andmonitored from anotherlocation
orroom.TheRC05canalsobeusedas a room
thermostatorprogrammableroomthermostat.
●external sensor – used in conjunction with the
RC05 the external sensor enables the
appliancetoautomatically adjust its outletflow
temperature in response to the outside
temperature.
Fig. 2
Flue Outlet Air Intake
AB CD
Expansion
vessel
Latent Heat
Collector
PAD
AARV
Pump
Main Heat
Exchanger
Main
Burner
GasValve
Domestic
Heat
Exchanger
Diverter
Valve Motor
Pressure
Switch DHW Flow
Switch

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SECTION 2 TECHNICAL DATA
2.1 Central heating Syntesi 25 Syntesi 29 Syntesi 35
Heat input 25.0 kW 29.0 kW 35.0 kW
Max heat output 60/80°C (return & flow temp.) 24.1 kW 28.0 kW 33.9 kW
Max heat output 30/50°C (return & flow temp.) 25.9 kW 29.7 kW 36.2 kW
Min heat output 60/80°C (return & flow temp.) 9.5 kW 9.5 kW 9.4 kW
Min heat output 30/50°C (return & flow temp.) 10.1 kW 10.2 kW 10.2 kW
Minimum working pressure 0.45 bar
Maximum working pressure 3.0 bar
Minimum flow rate 350 l/h
2.2 Domestic hot water
Maximum input 25.0 kW 29.0 kW 35.0 kW
Maximum output 24.1 kW 28.0 kW 33.9 kW
Minimum output 9.5 kW 9.5 kW 9.4 kW
Flow rate (35oC rise) 9.9 kW 11.5 kW 13.9 kW
Maximum inlet pressure 6.0 bar
Minimum inlet pressure 0.15 bar
Minimum flow rate 2.0 l/min
2.3 Gas pressures
Inlet pressure (G20) 20.0 mbar
Burner pressure maximum 8.8 mbar 9.3 mbar 10.1 mbar
Burner pressure minimum 1.5 mbar 1.25 mbar 1.00 mbar
Maximum gas rate 2.65 Sm3/h 3.07 Sm3/h 3.75 Sm3/h
Minimum gas rate 1.05 Sm3/h 1.05 Sm3/h 1.05 Sm3/h
Injector size (quantity) 12 x 1.35 mm 14 x 1.35 mm 16 x 1.35 mm
2.4 Expansion vessel
Capacity 8-litres 10-litres
Maximum system volume 76-litres 91-litres
Pre-charge pressure 1.0 bar
2.5 Dimensions
Height 820mm
Width 400mm 450mm 500mm
Depth 350mm
Dry weight (kg) 44.0 45.0 48.0
2.6 Clearances
Sides 12mm
Top 150mm from casing or 25mm above flue elbow (whichever is applicable)
Bottom 150mm
Front 600mm
2.7 Connections
Flow & return 22mm
Hot & cold water 15mm
Gas 15mm
Safety valve 15mm
Condense 21mm
2.8 Electrical
Voltage (V/Hz) 230/50
Power consumption 174W 174W 194W
Internal fuse 2A
External fuse 3A
2.9 Flue details (concentric)
Maximum horizontal flue length (60/100mm) 5.75m 4.90m 0.75m
Maximum vertical flue length (60/100mm) 6.55m 5.70m 1.55m
Maximum horizontal flue length (80/125mm) 13.80m 11.80m 6.75m
Maximum vertical flue length (80/125mm) 15.30m 13.30m 8.25m
2.9A Flue Details (twin pipes)
Maximum horizontal flue length (80mm + 80mm) 25m+25m 20m+20m 10m+10m
Maximum vertical flue length (80mm + 80mm) 25m+25m 20m+20m 10m+10m
2.10 Efficiency
SEDBUK (%) 87.4 87.5 88.1

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2.11 PUMP DUTY
Fig. 3 shows the flow-rate available – af-
terallowing for pressureloss through the
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
2.12 Emissions
NOx max/min 160/140 180/120 160/110
CO max/min 70/20 100/60 90/80
CO2 max/min 6.5/4.8 6.60/4.15 6.5/3.7
CO/CO2 ratio max/min 0.00108 to 1/0.00044 to 1 0.00152 to 1/0.00145 to 1 0.00138 to 1/0.00216 to 1
Syntesi 25 Syntesi 29
Fig. 4
Syntesi 35
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 1300
Syntesi 35
Syntesi 25& 29
Appliance
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
HH

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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
accordancewiththe relevant requirementsofthe
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.
Itshould be in accordance alsowith any relevant
requirements of the local authority and the
relevantrecommendationsofthefollowingBritish
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
provisionsoftheBuildingRegulations,withrespect
to the installation of the appliance in a room or
internal space containing a bath or shower.
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.
The location chosen for the appliance must per-
mit the provision of a safe and satisfactory flue
and termination. The location must also permit
an adequate air supply for combustion purposes
and an adequate space for servicing and air cir-
culation around the appliance. Where the instal-
lation of the appliance will be in an unusual loca-
tion special procedures may be necessary, BS
6798 gives detailed guidance on this aspect. A
compartmentusedtoenclosetheappliance must
be designed and constructed specifically for this
purpose.Anexisting compartment/cupboard may
be utilised provided that it is modified to suit.
Detailsofessentialfeaturesofcompartment/cup-
board design including airing cupboard installa-
tions are given in BS 6798. This appliance is not
suitable for external installation.
3.3 GAS SUPPLY
The gas meter – as supplied by the gas supplier
–mustbecheckedtoensurethat it is of adequate
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.
Ifthegassupplyservesmorethanoneappliance,
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
dispersalof combustion products is notimpeded
and with due regard for the damage and
discolorationthat may occur to buildingproducts
locatednearby.Theterminal must notbe located
in a place where it is likely to cause a nuisance
(see fig. 4).
3.4 FLUE SYSTEM (Cont’d.)
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.
Thisappliance is aroom-sealed, fan-flued boiler,
consequently it does not require a permanent
airventfor combustion air supply.When installed
in a cupboard or compartment, ventilation for
cooling purposes is also not required.
BS 5440 PART 1 FLUES
BS 5440 PART 2 FLUES & VENTILATION
BS 5449 PART1 FORCED CIRCULATION HOT WATER SYSTEMS
BS 5546 INSTALLATION OF GAS HOT WATER SUPPLIES FOR DOMESTIC PURPOSES
(2nd FAMILY GASES)
BS 6798 INSTALLATION OF BOILERS OF RATED INPUT NOT EXCEEDING 60kW
BS 6891 LOW PRESSURE INSTALLATION PIPES
BS 7074 PART1 APPLICATION, SELECTIONAND INSTALLTION OF EXPANSION VESSELS AND
ANCILLARY EQUIPMENT FOR SEALED WATER SYSTEMS

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3.6 WATER CIRCULATION
Detailedrecommendations are givenin BS 5449
Part 1 and BS 6798. The following notes are for
general guidance only.
3.6.1 PIPEWORK
Itisrecommended that coppertubingto BS 2871
Part 1 is used in conjunction with soldered
capillary joints.
Where possible pipes should have a gradient to
ensureairiscarried naturally to airreleasepoints
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
attentionshouldbepaid to pipes passing through
ventilatedareas 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
Thesemust be located in accessiblepositions to
facilitate draining of the appliance and all water
pipesconnected totheappliance.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 EXPANSION VESSEL
The appliance has an integral expansion vessel
to accommodate the increased volume of water
when the system is heated. It can accept up to 8
litres (25/29) or 10 litres (35) 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 (see 6.19).
3.6.6 FILLING POINT
A method for initial filling of the system and
replacingwater lost duringservicingetc.hasbeen
provided.This methodof filling complies with the
currentWaterSupply(WaterFittings)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
andstopcockforisolationpurposes.Thefeedpipe
should be connected to the return pipe as close
to the boiler 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
aspectsof the system are capable 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
completeisolationfrom the supply.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 SHOWERS
Iftheappliance is intendedfor use with ashower,
the shower must be thermostatically controlled
andbe suitable foruse with a combination boiler.
3.9 MOUNTING ON A COMBUSTIBLE SURFACE
If the appliance is to be fitted on a wall of com-
bustible material, a sheet of fireproof material
must protect the wall.
Fig. 5
Make-up vessel
or tank
Automatic
air-vent
Non-return
valve Stopcock
5.0 metres minimum
Heating
return

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3.10 TIMBER FRAMED BUILDINGS
If the appliance is to be fitted in a timber framed
building,itshould be fitted inaccordancewith the
Institute of Gas Engineers publication (IGE/UP/
7) ‘Guide for Gas Installations in Timber Frame
Buildings’.
3.11 INHIBITORS
Vokera recommend that a inhibitor – suitable for
usewith low water-content,copperheatexchang-
ers – is used to protect the boiler and system
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
accordancewiththe relevant requirementsofthe
local building regulations, the current ETCI
NationalRulesforElectrical Installations, and the
bylaws of the local water undertaking.
Itshould be in accordance alsowith any relevant
requirementsof the local and/ordistrict authority.
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
NationalRulesforElectricalInstallations,and I.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.
Thelocation chosen for theappliancemustpermit
the provision of a safe and satisfactory flue and
termination. The location must also permit an
adequate air supply for combustion purposes and
anadequate spaceforservicingand aircirculation
aroundthe appliance.Wheretheinstallationof the
appliance will be in an unusual location special
proceduresmaybenecessary,referto 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
–mustbecheckedtoensurethat it is of adequate
size to deal with the maximum rated input of all
SECTION 3A GENERAL REQUIREMENTS (EIRE)
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.
Ifthegassupplyservesmorethanoneappliance,
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
dispersalof combustion products is notimpeded
and with due regard for the damage and
discolorationthat may occur to buildingproducts
locatednearby.Theterminal must notbe located
in a place where it is likely to cause a nuisance
(see I.S. 813).
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.
Referto I.S. 813,when the terminalis 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.
Thisappliance is aroom-sealed, fan-flued boiler,
consequentlyit does not require a permanent air
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 notes are for general guidance only.
from the effects of corrosion and/or electrolytic
action.Theinhibitormustbeadministeredinstrict
accordancewiththemanufacturers* instructions.
*Fernox and Sentinel manufacture products that
have proved suitable for use with Vokera appli-
ances. Vokera Ltd. cannot comment on the suit-
ability of any other such product with our
appliances.

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8
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
ensureairis carried naturally toairrelease points
and that water flows naturally to drain cocks.
Exceptwhereprovidinguseful heat, pipes should
be insulated to avoid heat loss and in particular
to avoid the possibility of freezing. Particular
attentionshouldbepaid to pipes passingthrough
ventilatedareas suchas 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
Thesemust belocated 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.
3A.6.5 EXPANSION VESSEL
The appliance has an integral expansion vessel
to accommodate the increased volume of water
when the system is heated. It can accept up to 8
litres (25/29) or 10 litres (35) 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 (see 6.19).
3A.6.6 FILLING POINT
A method for initial filling of the system and
replacingwater lost duringservicingetc.hasbeen
provided.Youshould ensure thismethodof 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
aspectsof the system arecapableofwithstanding
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
completeisolationfrom the supply.The preferred
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 SHOWERS
Iftheappliance is intendedforuse with a shower,
the shower must be thermostatically controlled
andbe suitable foruse with acombination boiler.
3A.9 MOUNTING ON A COMBUSTIBLE SURFACE
If the appliance is to be fitted on a wall of
combustiblematerial,asheetoffireproofmaterial
must protect the wall.
3A.10 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’givesspecificadvice on thistype
of installation.
3A.11 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.12 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.

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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 fixing jig and 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
protectivepackaging from theappliance, and lay
theaccessories etc. tooneside.Protectivegloves
shouldbeusedto lift 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 must be
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, carefully mark the position of the
combined fixing jig and wall- mounting bracket
(see fig. 6A), and – using the template supplied
–markthe position of theflue-hole(if applicable).
4.5 FITTING THE 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)
Theappliancecanbeused with either the Vokera
condensing60/100mm concentric fluesystem or
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 2.9). A reduction must
also be made to the maximum length (see table
below) when additional bends are used.
Fig. 6
Fig. 6A

Supplied By www.heating spares.co Tel. [phone]
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 45º bend (pair) N/A
0225735 90º bend N/A
0225760 Wall bracket (5) N/A
Bend Reductionin maximum flue length for each bend
45°bend 0.5 metre
90°bend 1.0 metre
Reduction for additional bends
Using the template provided, mark and drill a
115mm hole forthe passage ofthe flue pipe.The
hole should have a 1°rise from the boiler to
outside,to ensure anycondense fluid thatforms,
is allowed to drain back to the appliance.
The fixing holes for the wall-mounting bracket/
fixing jig should now be drilled and plugged, an
appropriate type and quantity of fixing should be
used to ensure that the bracket/jig is mounted
securely. Once the bracket/jig has been secured
tothewall, mount the applianceonto the bracket.
FITTING THE 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 Dimension Y (see fig
7A).Measure dimensionYfrom the terminalend
of the concentric flue pipe and cut off the excess
ensuring any burrs are removed. Pass the
concentricfluepipe through the previouslydrilled
hole.Fit the flue bend tothe 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
fluebend to theappliance flue spigot.The60mm
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 EXTENDING THE FLUE
Connect the bend – supplied with the terminal
kit–tothe top of the boilerusingclamp(supplied)
seefig. 7.Theadditionalbends& extensionshave
push-fit connections, care should be taken to
ensure that the correct seal is made when
assemblingthe flue system. Connect the required
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 anycondense fluid thatforms,
is allowed to drain back to the appliance.
NOTE
Whencuttinganextension to the requiredlength,
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 connected.
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

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4.5.2 CONCENTRIC VERTICAL FLUE
Theappliancecanbeused with either the Vokera
condensing60/100mm concentric fluesystem or
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 (see 4.4.2),
howeverifadditionalbends are fitted, areduction
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 givenin fig. 9as a reference, 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-mountingbracketshould 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.
Fig. 9
IMPORTANT
The vertical flue terminal is 1.0 metre in length
andcannot be cut; thereforeit may benecessary
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

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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 kitt 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 45º bend (pair) N/A
0225845 90º bend (pair) N/A
0225850 Twin bracket (5) N/A
0225855 Single bracket (5) N/A
Twin flue accessories
MOUNTING THE BOILER
Thefixingholesforthewall-mountingbracketshould 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.
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.
●Removetheblankingplate (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 a3mm hole in each and secure the
air inlet pipe/bend using the screws provided.
●Thetwin flue 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
Whencuttinganextension to the requiredlength,
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
TheVokera twin fluesystem enables greaterflue
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 must alsobe
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,use at least one bracket
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.
●Asthe exhaust outletpipe can reachvery high
temperatures it must be protected to prevent
persons touching the hot surface.
●Thecondensatedrainpipe must be connected
in accordance with building regulations.
Fig. 10
C
AB
Fig. 11

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4.5.3.2 HORIZONTAL TERMINATION (see fig. 12)
The twin flue system must be converted to the
dedicated concentric flue kit for termination.
●Thehorizontal terminal is suppliedwith 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.
Dependingonsiteconditionsitmaybepreferable
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°fallbacktotheboiler(17mm per 1000mm).
Insert the terminal assembly into the flue hole.
Push-fitthe twin flue pipes onto the concentric to
twinconverterboxensuring that the exhaustpipe
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
havebeenmadeforconnectionontotheprevious
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
theconcentricterminalthroughtheceilingand/
or roof.
Dependingonsiteconditionsitmaybepreferable
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 concentric to
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°fall towards the appliance (17mm
per 1000mm).
1.0-metre
1-deg. = 17mm

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4.6 CONNECTING THE GAS AND WATER
The appliance is supplied with a fixing jig that
includes service valves (fig. 14). The service
valves are of the compression type. The
accessories pack contains sealing washers etc,
for use with the service valves.
Whenconnectingpipe work to thevalves,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
Filling Loop
Cold water Inlet
Stopcock/filling
valve
Hot water
Outlet
Gas
Cock
Safety valve
outlet
C/H return
valve
C/H flow
valve
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
necessarytoincreasethesizeoftheflow&return
pipe work after the service valve connections.
4.6.3 COLD WATER INLET (see fig. 6A & 14)
Theapplianceissuppliedwitha 15mm combined
stopcock and double check-valve, connect a
15mmpipetotheinletofthestopcockand tighten
both nuts.
4.6.4 HOT WATER OUTLET (see fig. 6A & 14)
The appliance is supplied with a 15mm outlet
connection, connect a 15mm pipe to the outlet
connection and tighten both nuts.
4.6.5 SAFETY VALVE (see fig. 6A & 14)
Connect the safety valve connection pipe
betweenthe safety valve outlet and the fixing jig.
Fig. 13

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Connect a discharge pipe to the fixing jig
connectionand tighten.Thedischarge pipe must
have a continuous fall away from the appliance
to outside and allow any water to drain away
therebyeliminatingthepossibilityoffreezing.The
dischargepipemustterminateinaposition where
any water – possibly boiling – discharges safely
without causing damage or injury, but is still
visible.
4.6.6 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.
CONNECTING THE CONDENSATE OUTLET
Gently pull the condense outlet pipe down from
its location inside the boiler until approximately
200mmprotrudes from theundersideoftheboiler.
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 – external to the appliance – are
required,acompetentpersonmustundertakethe
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
To gain internal accesstotheappliance you must
first remove the casing, proceed as outlined
below:
●pressthecontrolscovertorelease the controls
cover catch
●locate and unscrew the 2 screws that secure
thecontrolsfasciatotheappliancecasing(see
fig 15)
●gently lower the control fascia until it rests
●removethe2 screws located at the 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.
Fig. 15
4.7.2 APPLIANCE TERMINAL 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
blockcover.
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
controlswill be required pleaserefer to thewiring
diagrams in section 8 for more detailed
information.
4.7.3 CONNECTING THE MAINS (230V) INPUT (see
fig. 16)
Remove the terminal block cover as described
in 4.7.2. Pass the cable through the cable
anchorage point. At plug M16 on the appliance
control PCB there are 7 terminals from Front to
Back they are:
1. NEUTRAL
2. NEUTRAL (supply for clock)
3. LIVE
4. LIVE (supply to clock)
5. TA
6. TA
7. (Spare)
Connect the supply cable wires (LIVE, and
NEUTRAL) to their corresponding terminals on
theappliance terminal block. Connect the EARTH
wire to the EARTH block (see fig. 16) ensuring
thatit’sleft slightly longerthat the others, this will
prevent strain on the EARTH wire should the
cable become taut.
A

Supplied By www.heating spares.co Tel. [phone]
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Donotremovethelinkwire(betweenTA& Spare)
unlessadditionalexternal controls are tobe fitted
(see section 8).
4.7.4 CONNECTING THE VOKERA TIME CLOCK
(part no. 201 & 202)
The appliance is supplied with a clock connector
plug that is connected to plug M16 on the
appliance terminal block. The clock connector
plug is for use with the clock harness that is
included in the accessory pack and facilitates an
easyconnection to theoptionalVokeratimeclock.
To fit the Vokera time clock:
●remove the appliance PCB cover
●remove and discard the wiring harness
supplied with the clock
●using the clock wiring harness supplied in the
accessory pack, connect the 4-wires to the
clock as shown in fig 16.
Fig. 16
Fig. 17
●remove the clock aperture plate from the
appliance
●remove the push-out blanking disc from the
clock aperture plate (fig. 17)
●secure the clock to the aperture plate using
the screws provided with the clock (fig. 17)
●refittheclockaperture plate ensuring the clock
is positioned the correct way up
●remove the Red link-wire plug from the
appliance clock connector plug
●connect the clock wiring harness to the clock
connector plug
●re-fit the appliance PCB cover and terminal
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.

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17
5.1 GAS SUPPLY INSTALLATION
Inspect the entire installation including the gas
meter, test for soundness and purge. Refer to
BS 6891 for specific instruction.
5.2 THE HEATING SYSTEM
The appliance contains components that may
becomedamaged or rendered inoperableby oils
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.
Fig. 18
5.3 INITIAL FILLING OF THE SYSTEM
Ensure both flow and return service valves are
open, remove appliance casing as described in
4.7.1,identifytheautomaticair release valve and
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
manualair release valveslocated on the heating
system are closed. Connect the filling loop as
shown in fig. 6, slowly proceed to fill the system
byfirstly opening the inletvalve connected tothe
flow valve, and then turning the lever on the
combinedstopcockand check valve, tothefilling
position(see fig. 18).Aswater enters the system
the pressure gauge will begin to rise. Once the
gauge has reached 1 bar close both valves and
begin venting all manual air release valves,
starting at the lowest first. It may be necessary
togo back and top-up the pressure until the entire
system has been filled. Inspect the system for
water soundness, rectifying any leaks.
5.4 INITIAL FLUSHING
Thewholeofthe heating system must beflushed
both cold and hot as detailed in 5.8. Open all
radiatoror heating valvesand 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 FILLING THE HOT WATER SYSTEM
Close all hot water outlets, turn appliance
stopcockto the normal operating position (fig.18),
slowlyopen each outletuntilairhasbeenexpelled
and clear water is discharged. Check pipe-work
etc. for water soundness.
5.6 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
●ensurethe proper electrical checkshave been
carried out, (see 7.7) particularly continuity,
polarity, and resistance to earth
●ensure the 3 amp fuse – supplied with the
appliance – has been fitted.
●ensurethesystemhas been filled, vented,and
the pressure set to 1 bar.
●ensurethefluesystemhasbeen fitted properly
and in accordance with the instructions.
●ensure all appliance service valves are open.
5.7 INITIAL LIGHTING
Ensure the electrical supply to the appliance is
switched on. Move the selector switch to the
Heating & Hot Water position, ensure the time
clock is switched to an ‘ON’ position and ensure
any other external controls are also calling for
heat.
The appliance will now operate in the pre-heat
mode as described in 1.2. Once the pre-heat
function has been completed, the appliance will
operatein the central heatingmode as described
in 1.3. Should the appliance fail to ignite, refer to
5.6 and/or section 7 (faultfinding).
5.7.1 CHECKING THE BURNER PRESSURE
Although the burner pressure is factory set, it is
necessary to check it during commissioning.
Isolate the appliance from the electrical supply
andattacha suitable manometer tothegas valve
outlet test-point (see fig. 19). Light the boiler as
described in 5.7, turn the Hot Water temperature
selectorto maximum, and openfullyaDHWoutlet
(preferably the bath), allowing the appliance to
stabilise.Comparethereadingonthemanometer
with the value described in 2.3. If adjustment is
required,follow the detailed instructions in section
7 (7.3).
Once the burner pressure has been checked,
close the DHW outlet, isolate the appliance from
theelectricalsupply, remove the manometer,and
tighten the gas valve outlet test nipple.
Normal
Operating
Position
Filling
Position
Closed
Position
SECTION 5 COMMISSIONING

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5.8 FINAL FLUSHING OF THE 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.
*BothSentinelandFernox 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.
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 Heating thermostat
knob (see fig.1).
5.9.1 SETTING THE DOMESTIC HOT WATER TEM-
PERATURE
The DHW outlet temperature can be adjusted
between 40°C - 65°C via the Hot Water
thermostat knob (see fig.1).
5.10 SETTING THE 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
theequivalent height in metres (0.1 bar = 1 metre)
tothe highest pointin the system above 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,pullleveronheadofsafetyvalvetorelease
water until the required figure registers on the
pressure gauge (see fig. 1).
5.11 REGULATING THE HOT WATER
The appliance is fitted with a flow rate restrictor
that limits the maximum flow rate that can be
drawn through the appliance.
Syntesi 25 8-litre 9-litre
(Orange) (Blue)
Fitted Spare
Syntesi 29
9-litre 10-litre 11-litre
(Orange) (Blue) (Beige)
Spare Fitted Spare
Syntesi 35
11-litre 12-litre 13-litre
(Beige) (Red) (Olive)
Spare Fitted Spare
The restrictor eliminates the need to manually
adjust the DHW flow rate. However if it is felt
necessary to further increase or decrease the
availableflow rate, sparerestrictors are included
in the accessory pack.
The spare flow rate restrictors can be fitted to
either increase or decrease the maximum flow
rate.Thetables above denotethesizeofrestrictor
fitted and the spare restrictors supplied in the
accessory pack. Each restrictor is colour-coded
to enable identification.
5.11.1 CHANGING THE FLOW RESTRICTOR
Referto 6.19 fordetailed instruction onchanging
the flow restrictor.
5.11.2 REGULATING THE CENTRAL HEATING
SYSTEM
Fully open all radiator and circuit valves and run
theappliance for bothheating and hotwater until
heatedwateriscirculating.Ifconditions are warm
remove any thermostatic heads. Adjust radiator
returnvalvesandany branch circuit returnvalves
untilthe individual return temperatures arecorrect
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
ISFITTED CORRECTLYANDIS PROPERLY
SECURED.
●ENSUREALLPIPE WORKIS RE-CHECKED
FOR SOUNDNESS.
●RE-FIT APPLIANCE CASING.
●COMPLETE APPLIANCE LOGBOOK.
Fig. 19
Protective
cap
Outlet
test-point
Inlet
test-point