Riello Vokera Vision C User manual

Users Instructions
Installation &
Servicing
Instructions
THESE INSTRUCTIONS
TO BE RETAINED
BY USER
Vokèra is a licensed member of the Benchmark scheme
which aims to improve the standards of installation and
commissioning of domestic hot water systems in the UK.
Vision C
High e󰀩ciency combi boiler
Vision 25 C G.C. N° 47-364-10
Vision 30 C G.C. N° 47-364-11

1. THINGS YOU SHOULD KNOW...................................................1
1.1 GAS APPLIANCES..................................................................1
1.2 ELECTRICAL SUPPLY............................................................1
1.3 GUARANTEE REGISTRATION CARD...................................1
1.4 APPLIANCE COMMISSIONING CHECKLIST (UK only)........1
1.5 HOW DOES IT WORK?..........................................................1
1.6 DIMENSIONS..........................................................................1
1.7 CLEARANCES REQUIRED....................................................1
1.8 FROST PROTECTION SYSTEM............................................1
1.9 APPLIANCE STATUS INDICATORS.......................................1
1.10 GAS APPLIANCES..................................................................3
1.11 MODES OF OPERATION .......................................................4
1.12 SETTING THE TIME AND DAY...............................................4
1.13 CHANGING THE HEATING PATTERN...................................4
1.14 ADVANCE FUNCTION............................................................4
1.15 MODE OF OPERATION..........................................................4
1.16 RESET HEATING PROGRAM TO DEFAULT VALUES...........4
2. GETTING STARTED....................................................................5
2.1 BEFORE SWITCHING ON......................................................5
2.2 APPLIANCE CONTROLS ......................................................5
2.3 LIGHTING THE BOILER .........................................................5
2.4 ADJUSTING THE HEATING TEMPERATURE .......................5
2.5 ADJUSTING THE HOT WATER TEMPERATURE..................5
2.6 EXPLANATION OF FEATURES..............................................5
2.7 AUTOMATIC TEMPERATURE CONTROL.............................5
3. HOW TO.......................................................................................5
3.1 HOW TO TOP-UP THE SYSTEM PRESSURE ......................5
3.2 HOW TO FILL THE CONDENSATE TRAP..............................5
3.3 HOW TO RESET THEAPPLIANCE................................................5
3.4 HOW TO SHUT DOWNTHE SYSTEM FOR SHORT PERIODS 6
3.5 HOW TO SHUTDOWN THE SYSTEM FOR LONG PERIODS ..6
3.6 HOW TO CARE FOR THEAPPLIANCE.................................6
4. WHAT IF.......................................................................................6
4.1 WHAT IF I SUSPECTA GAS LEAK ........................................6
4.2 WHAT IF I HAVE FREQUENTLY TO TOP-UP THE SYSTEM....6
4.3 WHAT IF THEAPPLIANCE IS DUE ITSANNUAL SERVICE ....6
4.4 WHAT IF I NEED TO CALLAN ENGINEER............................6
INSTALLATION AND SERVICING INSTRUCTIONS..................7
SECTION 1 - DESIGN PRINCIPLES AND OPERATING
SEQUENCE .....................................................................................8
1.1 PRINCIPLE COMPONENTS...................................................8
1.2 MODE OF OPERATION (at rest) ............................................8
1.3 MODE OF OPERATION (Heating)..........................................8
1.4 MODE OF OPERATION (Hot water).......................................8
1.5 SAFETY DEVICES..................................................................8
SECTION 2 - TECHNICAL DATA....................................................9
2.1 CENTRAL HEATING..............................................................9
2.2 DOMESTIC HOT WATER......................................................9
2.3 GAS PRESSURES................................................................9
2.4 FAN SPEED (G20).................................................................9
2.5 EXPANSION VESSEL...........................................................9
2.6 DIMENSIONS.........................................................................9
2.7 CLEARANCES.......................................................................9
2.8 CONNECTIONS.....................................................................9
2.9 ELECTRICAL.........................................................................9
2.10 FLUE DETAILS (CONCENTRIC 60-100) .............................9
2.10AFLUE DETAILS (CONCENTRIC 80-125) .............................9
2.10B FLUE DETAILS (TWIN PIPES).......................................9
2.11 EFFICIENCY..........................................................................9
2.12 EMISSIONS............................................................................9
2.13 PUMP....................................................................................11
SECTION 3 - GENERAL REQUIREMENTS (UK).........................12
3.1 RELATED DOCUMENTS......................................................12
3.2 LOCATION OF APPLIANCE .................................................12
3.3 GAS SUPPLY........................................................................12
3.4 FLUE SYSTEM......................................................................12
3.5 AIR SUPPLY..........................................................................12
3.6 WATER CIRCULATION.........................................................12
3.7 ELECTRICAL SUPPLY..........................................................13
3.8 MOUNTING ON A COMBUSTIBLE SURFACE.....................13
3.9 TIMBER FRAMED BUILDINGS ............................................13
3.10 INHIBITORS..........................................................................13
3.11 SHOWERS............................................................................13
SECTION 3A - GENERAL REQUIREMENTS (EIRE)....................13
3A.1 RELATED DOCUMENTS......................................................13
3A.2 LOCATION OF APPLIANCE .................................................13
3A.3 GAS SUPPLY........................................................................13
3A.4 FLUE SYSTEM......................................................................13
3A.5 AIR SUPPLY..........................................................................14
3A.6 WATER CIRCULATION.........................................................14
3A.7 ELECTRICAL SUPPLY..........................................................14
3A.8 MOUNTING ON A COMBUSTIBLE SURFACE.....................14
3A.9 TIMBER FRAMED BUILDINGS ............................................14
3A.10 INHIBITORS.........................................................................14
3A.11 SHOWERS...........................................................................14
3A.12 DECLARATION OF CONFORMITY.....................................14
SECTION 4 - INSTALLATION .......................................................15
4.1 DELIVERY ..........................................................................15
4.2 CONTENTS...........................................................................15
4.3 UNPACKING .........................................................................15
4.4 PREPARATION FOR MOUNTING THEAPPLIANCE...........15
4.5 FITTING THE FLUE ..............................................................15
4.6 CONNECTING THE GASAND WATER................................19
4.7 ELECTRICAL CONNECTIONS.............................................19
SECTION 5 - COMMISSIONING ...................................................20
5.1 GAS SUPPLY INSTALLATION..............................................20
5.2 THE HEATING SYSTEM.......................................................20
5.3 INITIAL FILLING OF THE SYSTEM......................................20
5.4 INITIAL FLUSHING OF THE SYSTEM .................................20
5.5 PRE-OPERATION CHECKS.................................................20
5.6 INITIAL LIGHTING.................................................................20
5.7 CHECKING GAS PRESSUREAND COMBUSTION ANALYSIS20
5.8 FINAL FLUSHING OF THE HEATING SYSTEM...................20
5.9 SETTING THE FLOW OUTLET TEMPERATURE ................20
5.10 SETTING THE SYSTEM DESIGN PRESSURE ...................20
5.11 REGULATING THE CENTRAL HEATING SYSTEM.............21
5.12 FINAL CHECKS.....................................................................21
5.13 INSTRUCTING THE USER...................................................21
SECTION 6 - SERVICING INSTRUCTIONS..................................21
6.1 GENERAL..............................................................................21
6.2 ROUTINE ANNUAL SERVICING ..........................................21
6.3 REPLACEMENT OF COMPONENTS...................................21
6.4 COMPONENT REMOVAL PROCEDURE.............................22
6.5 PUMPASSEMBLY ...............................................................22
6.6 SAFETY VALVE ....................................................................22
6.7 LOWER AUTOMATIC AIR RELEASE VALVE .......................22
6.8 WATER PRESSURE SWITCH .............................................22
6.9 FLOW THERMISTOR ...........................................................22
6.10 RETURN THERMISTOR.......................................................22
6.11 PRINTED CIRCUIT BOARD ................................................23
6.12 GAS VALVE ..........................................................................23
6.13 ELECTRODES .....................................................................23
6.14 FLUE FAN & MIXER .............................................................23
6.15 BURNER ...............................................................................23
6.16 MAIN HEAT EXCHANGER....................................................24
6.17 AUTOMATIC BY-PASS & DHW NON-RETURN....................24
6.18 EXPANSION VESSEL REMOVAL ........................................24
6.19 CONDENSE TRAP REMOVAL..............................................24
6.20 FLUE COLLECTOR REMOVAL ...........................................25
SECTION 7 - CHECKS, ADJUSTMENTS AND FAULT FINDING ....26
7.1 CHECKING APPLIANCE OPERATION.................................26
7.2 APPLIANCE MODES OF OPERATION................................26
7.3 CHECKING THE CO2AND ADJUSTING THE GAS VALVE .26
7.4 COMBUSTION ANALYSIS TEST..........................................27
7.5 CHECKING THE EXPANSION VESSEL...............................27
7.6 EXTERNAL FAULTS .............................................................27
7.7 ELECTRICAL CHECKS.........................................................27
7.8 FAULT FINDING....................................................................28
7.9 COMPONENT VALUES & CHARACTERISTICS..................28
7.10 ADJUSTMENTS....................................................................28
SECTION 8 - WIRING DIAGRAMS ...............................................30
8.1 EXTERNAL WIRING .............................................................30
8.2 OTHER DEVICES.................................................................30
SECTION 9 - LPG INSTRUCTIONS..............................................32
9.1 RELATED DOCUMENTS......................................................32
9.2 TECHNICAL DATA................................................................32
9.3 CONVERTING THEAPPLIANCE GAS TYPE.......................32
9.4 GAS SUPPLY........................................................................32
9.5 GAS SUPPLY INSTALLATION..............................................32
9.6 CHECKING THE CO2ANDADJUSTING THE GAS VALVE ....32
Commissioning checklist........................................................... 34
Benchmark.............................................................................. 35-37
Vokèra Warranty Terms and Conditions ....................................39

1
USERS INSTRUCTIONS
1.1 GAS APPLIANCES
Gas Safety (Installation and Use) Regulation (UK).
In the interests of your safety and that of others it is a legal
requirement that all gas appliances are installed and correctly
maintained by a competent person and in accordance with the
latest regulations.
1.2 ELECTRICAL SUPPLY
Pleaseensurethatthisappliancehasbeenproperlyconnected
to the electrical supply by means of a double pole isolator or
un-switched socket, and that the correct size of fuse (3 AMP)
has been tted.
Warning: this appliance must be earthed!
1.3 GUARANTEE REGISTRATION CARD
Please take the time to ll out your guarantee registration card.
The completed warranty card should be posted within 30 days
of installation.
1.4 APPLIANCE COMMISSIONING CHECKLIST
(UK only)
A checklist section can be found at the rear of the appliance
installation booklet. This important document must be com-
pleted during the installation/commissioning of your boiler. All
GAS SAFE registered installers carry a GAS SAFE ID card,
and have a registration number. These details should be re-
corded in the Benchmark commissioning checklist section
within the installation booklet. You can check your installers
details by calling GAS SAFE direct on 08004085500. Failure
to install and commission the appliance in accordance with
the manufacturers instructions will invalidate the warranty.
This does not a󰀨ect your statutory rights.
1.5 HOW DOES IT WORK?
Your Vision boiler supplies heated water to your radiators and
hot water to your hot water taps. The central heating is con-
trolled via a time clock and any thermostats that your installer
may have tted. The boiler will light when it receives a request
from the time clock via any thermostat that may be installed, or
whenever a hot water outlet (tap) is opened. Your Vision boiler
lights electronically and does not have a pilot light.
In the unlikely event of a fault developing with your boiler, the
supply of gas to the burner will be terminated automatically.
Dear Customer
Your Vokèra Vision boiler has been designed to meet and exceed the very latest standards in gas central heating technology,
and if cared for, will give years of reliable use and e󰀩ciency.
Please therefore take some time to read these instructions carefully.
Do’s and Don’t’s
- Do ensure that the system pressure is periodically checked
- Do ensure that the boiler should not be used by children or unassisted disabled people
- Do ensure that you know how to isolate the appliance in an emergency
- Do ensure that you are familiar with the appliance controls
- Do ensure that your installer has completed the appliance log book section
- Do not attempt to remove the appliance casing or gain internal access
- Do not hang clothes etc. over the appliance
- Do not forget to have the appliance serviced annually.
At the end of its life, the product should be not be disposed of as solid urban waste, but rather it should be handed over
to a di󰀨erentiated waste collection centre.
INTRODUCTION
1.7 CLEARANCES REQUIRED
1.8 FROST PROTECTION SYSTEM
The Vision is equipped with a built-in frost protection system,
this enables the boiler to over-ride the time controls – even if
switched o󰀨 – and operate the burner and/or pump, should
the temperature drop below 50C for the main and for the DHW
line. In particular the burner will be in ON status until the main
temperature reaches 35°C for CH appliance and 55°C for
DHW appliance. Please note that the frost protection system
is designed to protect the appliance only, should frost protec-
tion be required for the heating system, additional controls
may be required.
NOTE
The frost protection system is reliant on the appliance having a
permanentelectrical supply,and beingin anon-fault condition.
1.9 APPLIANCE STATUS INDICATORS
Your boiler is equipped with a large LCD display that indicates
the appliance operating status.
1. THINGS YOU SHOULD KNOW
Vision 25C - 30C
HEIGHT 715 mm
WIDTH 405 mm
DEPTH 250 mm
ABOVE 150 mm
BELOW 150 mm
LEFT SIDE 12 mm
RIGHT SIDE 12 mm
FRONT 600 mm
1.6 DIMENSIONS

2
Fig. 1
HOT WATER TEMPERATURE SELECTOR
Move the selector clockwise to increase the hot water outlet temperature, or counter-clockwise to reduce the temperature
PRESSURE GAUGE
Ensure the system pressure is set correctly (minimum 0.5-bar)
MODE SELECTOR SWITCH/HEATING TEMPERATURE SELECTOR
Mode selector switch:
Hot water only - Select this position if you want the boiler to supply hot
water only (no heating)
Hot water temperature selector: move the selector clockwise to increase
theDHWoutlet temperature, or counter-clockwise to reduce thetemperature
(range: 37°C-60°C)
The display shows the temperature values.
Boiler at OFF/standby - Select this position when you want the boiler to
be switched o󰀨 for short periods (days) or if the boiler requires to be reset
The display shows “- -”.
Heating & hot water - Select this position when you want the boiler to re-
spond to a heating and hot water request from the time-clock programmer
Heating temperature selector:movetheselectorclockwisetoincreasethe
heating outlet temperature, or counter-clockwise to reduce the temperature
(range: 40°C-80°C for standard central heating).
The automatic temperature control function (SARA) is set within the blank
bullet points.
The display shows the temperature values.
Pressure gauge shows the current pressure of your heating system, the
gauge should be set between 1 and 1.5 BAR. When the appliance is oper-
ating the gauge may rise or fall slightly, this is quite normal. The minimum
permissible level for the safe and e󰀩cient operation of the appliance is 0.5
BAR. Should the pressure fall below 0.5 BAR, the boiler may lockout.
correct pressure
value
MODE SELECTOR SWITCH
HEATING TEMPERATURE SELECTOR
PRESSURE GAUGE
HOT WATER
TEMPERATURE
SELECTOR
ONOFF
DIGITAL WEEKLY CLOCK AND
BOILER STATUS DISPLAY
DHW pre-heat function - Turning the domestic hot water temperature
adjustment knob to the symbol activates the pre-heating function. Bring the
domestic hot water temperature adjustment knob back to the required po-
sition. The activation of this function is indicated on display with the P icon
ON. This function keeps the water in the domestic hot water exchanger hot,
to reduce standby times when a request is made. The display shows the
delivery temperature of the heating water or the domestic hot water, accor-
ding to the current request. To deactivate the pre-heat function, rotate the
domestic hot water temperature adjustment knob back to the symbol. Bring
the domestic hot water temperature adjustment knob back to the required
position. This function cannot be activated when the boiler is OFF: function
selector to OFF position.
CLOCK SETTING
BUTTONS

3
DIGITAL WEEKLY CLOCK
ONOFF
Fig. 2
Button/Icon Main Function Secondary Function
Used to set/adjust
time of day, and
day of week
N/A
Use to “advance”
the heating to an
ON period
Use to increase values when
setting clock & day of week.
Use to program ON periods
for heating pattern.
Use to “advance”
the heating to an
OFF period
Use to decrease values
when setting clock & day of
week. Use to program OFF
periods for heating pattern.
Use to change
mode of operation Use when installing a user dened heating program.
Symbol/Icon Description/Function
Used to show current day of week
(ashing)
Displayed when the ADVANCE-ON fun-
ction is active
Displayed when the ADVANCE-OFF fun-
ction is active
Displays current minutes past the hour
Displays current hour of the day
24-hour clock in 30 minute segments; lar-
ge segments represent hour mark, small
segments represent half-past the hour;
ashing segment represents actual time
Symbol/Icon Description
Displayed when heating mode is active
Displayed when hot water mode is active
Displayed when frost protection function is ac-
tive
Displayed when hot-water pre-heat function is
enabled. Flashes when functioning
Displayed if an alarm or fault has been detected
Displayed when low system pressure has been
detected
Displayed when an external sensor is connected
to the boiler
Displayed if an ignition fault has been detected
Displayed when the burner is ON
BUILT-IN CLOCK
The Vision 25C & 30C incorporate a built-in digital clock and
multi-informative LCD display.
1.10 GAS APPLIANCES
The digital clock is pre-programmed with a default heating
pattern (see table 1 below); however this can be modied to
suit individual needs (see 1.4).
Pre-programmed Heating Pattern
Day am pm
ON OFF ON OFF
Monday 06:30 08:30 4:30 10:30
Tuesday 06:30 08:30 4:30 10:30
Wednesday 06:30 08:30 4:30 10:30
Thursday 06:30 08:30 4:30 10:30
Friday 06:30 08:30 4:30 10:30
Saturday 08:00 10:00 4:00 11:00
Sunday 08:00 10:00 4:00 11:00
Table 1

4
1.11 MODES OF OPERATION
The built-in digital clock has the following modes of operation:
1. ON / OFF – where the clock uses the programmed
heating pattern (default or user dened) to switch the hea-
ting ON & OFF at pre-selected times (see Fig.1).
2. ON – where the clock is set to provide heating constan-
tly ON (in this mode the default or user dened heating
pattern is ignored).
3. OFF – where clock is set to have the heating constantly
OFF (in this mode the default or user dened heating pat-
tern is ignored).
4. ADVANCE ON – where the pre-programmed heating pat-
tern is advanced to the next ON period (this function can
only be used when the clock is in the OFF mode)
5. ADVANCE OFF - where the pre-programmed heating pat-
tern is advanced to the next OFF period (this function can
only be used when the clock is in the ON mode).
1.12 SETTING THE TIME AND DAY
Ensure that the boiler is electrically supplied.
1. Press and hold the clock button for 3-seconds; the
right hand digits (minutes) will ash continuously.
2. Press the up arrow button to increase the minutes va-
lue or press the down arrow button to decrease the
value.
3. Once the correct minutes value is displayed, press the
clock button to store this setting and move to the hours
value.
4. Press the up arrow button to increase the hours value
or press the down arrow button to decrease the value.
5. Once the correct hours value is displayed press the
clock button to store this setting and move to the day of
week value.
6. Press the up arrow button to move forward to the cor-
rect day of week (1 = Monday – 7 = Sunday)or press the
down arrow button to move back to the correct day of
week.
7. Once the correct day of week is displayed press the
clock button to store this setting and complete the time /
day of week, setting procedure.
NOTE: the time of day is shown on the display, and is also
indicated on the 24-segmented display as a ashing segment.
1.13 CHANGING THE HEATING PATTERN
The built-in clock is pre-programmed with a default heating
pattern (see Fig.1), however this can be changed to a user
dened heating pattern.
To insert a new heating pattern or change and existing one,
proceed as follows:
1. Press and hold the program button for 3-seconds
2. The day of week segment ashes to indicate which day of
week is being programmed
3. Use the up arrow button to select the required ON
periods and use the down arrow button to select the
OFF periods
NOTE: each segment represents 30-minutes, the large seg-
ments are hour indicators, and the small segments are half-
hour indicators.
4. When the ON and OFF selections have been made for the
particular day (relevant day of week is displayed by the ap-
propriate number 1 to 7) press the program button to
store the new settings and move to the next day.
NOTE
If you want to duplicate the new settings for subsequent days,
e.g. same heating pattern for Monday to Friday, press and
hold the program button for 3-seconds each time the ap-
propriate day of week is displayed.
EXAMPLE
Day of week = 1 (Monday) Insert the new ON & OFF settings
(step 3 above), press the button, day of week now shows
2 (Tuesday). Press the button for 3-seconds, Monday’s
settings are now duplicated for Tuesday; repeat as required.
5. If you require to change the settings for subsequent days,
repeat steps 3 & 4 above
6. Once programming has been completed, continue to press
and release the program button until you exit the pro-
gramming function (normal display is resumed).
1.14 ADVANCE FUNCTION
When the clock is in the ON or OFF mode, it’s possible
to advance the current setting (ON or OFF) to the next pro-
grammed setting (ON or OFF), e.g. if the clock is in OFF
mode it’s possible to advance to the next ON setting.
1.14.1 ADVANCE ON
Press and hold the up arrow button for 3-seconds, the
display changes from OFF to ON and the icon is
displayed.
NOTE, the ADVANCE ON function can be cancelled by mo-
mentarily pressing the button.
NOTE, when the ADVANCE ON function is enabled, the hea-
ting will remain ON until the next scheduled OFF period.
1.14.2 ADVANCE OFF
Press and hold the down arrow button for 3-seconds, the
display changes from ON to OFF and the icon is
displayed.
NOTE: the ADVANCE OFF function can be cancelled by mo-
mentarily pressing the button.
NOTE: when theADVANCE OFF function is enabled, the hea-
ting will remain OFF until the next scheduled ON period.
1.15 MODE OF OPERATION
To change the mode of operation ( to ) momentarily press
the button; the display will show the following:
• OFF Heating is in an OFF period according to the pro-
grammed heating pattern
• ON Heating is in an ON period according to the pro-
grammed heating pattern
• OFF Heating is being controlled manually and is
switched constantly OFF
• ON Heating is being controlled manually and is switched
constantly ON.
1.16 RESET HEATING PROGRAM TO DE-
FAULT VALUES
The heating pattern can be reset to the default values (see
g.1) by pressing and holding both buttons simulta-
neously for 3-seconds.
NOTE
This cancels any previously input, user dened settings.

5
2.1 BEFORE SWITCHING ON
Before switching the appliance on, please familiarise yourself
with:
- howtoisolatetheappliancefromthegas,water,andelectricity
supplies;
- how to check and top-up – if necessary – the system water
pressure;
- the time clock or programmer (if tted);
- any external thermostats and their functions;
- the appliance controls.
2.2 APPLIANCE CONTROLS (see g. 1)
The appliance controls are situated on the lower front of the
appliance. The appliance controls include:
- pressure gauge;
- appliance mode selector;
- temperature selectors;
- integral time clock.
NOTE
The appliance frost protection is active in all the boiler modes.
Thetemperatureselectorscanbeusedtovarythetemperature
ofthe waterthat circulatesaround your radiatorsand thewater
that ows from your hot water taps. The temperature range is
adjustable between 40oC and 80oC for the central heating, and
between 37oC and 60oC for the hot water.
The display normally shows the current time.
Refer to the main appliance status table for fault indicator and
boiler status.
The integral digital time clock is used to switch the heating on
and o󰀨 at pre-determined intervals.
2.3 LIGHTING THE BOILER
Ensure the gas and electrical supply to the boiler are
turned on.
Turn the mode selector switch to the ON position. When there
is a request for heating or hot water via the time clock or pro-
grammer, the boiler will begin an ignition sequence. When the
appliance reaches the CH set temperature, the burner will go
o󰀨 for a minimum period of approximately 3 minutes.
When the programmer/time clock or external thermostats
heating request has been satised, the appliance will switch
o󰀨 automatically.
2.4 ADJUSTING THE HEATING TEMPERATURE
Rotatethetemperatureselector–clockwisetoincrease,counter-
clockwisetodecrease–tothedesiredtemperaturesetting. The
temperaturecan beset fromaminimum of40°C toamaximum
of 80°C (if standard CH mode is selected).
2.5 ADJUSTING THE HOT WATER TEMPERA-
TURE
Rotate the temperature selector – clockwise to increase,
counter-clockwise to decrease – to the desired temperature
setting. The temperature can be set from a minimum of 37°C
to a maximum of 60°C. If the temperature at the outlet is still
not su󰀩ciently hot enough, it may be necessary to reduce the
ow of water at the hot water outlet (tap).
NOTE
If the appliance fails to ignite during the ignition sequence, it
will enter a lockout condition. Should this occur, please allow
aperiodof atleasttwominutes beforere-settingthe appliance.
2.6 EXPLANATION OF FEATURES
Although the Vokèra Vision has been designed for simplicity of
use, it utilises the latest in boiler technology, enabling a host of
functions to be carried out simultaneously.
2.7 AUTOMATIC TEMPERATURE CONTROL
The automatic temperature control function (SARA), permits
the boiler (when the heating temperature selector is set within
theblankbullet pointstoautomatically adjust(raise)theheating.
The activation and the disable of the function is visualized on
the display if the heating temperature is selected between 55°
-65°C.
2. GETTING STARTED
3.1 HOW TO TOP-UPTHE SYSTEM PRESSURE
(g. 1-2)
Thesystempressuremustbecheckedperiodicallytoensurethe
correctoperation ofthe boiler.Theneedle onthegauge should
be reading between 1 and 1.5 BAR when the boiler is in an o󰀨
position and has cooled to room temperature. If the pressure
requires ‘topping-up’ use the following instructions as a guide.
- Locate the lling valve connections (usually beneath the
boiler, see g. 3).
- Attach the lling loop to both connections.
- Open the lling valve slowly until you hear water entering the
system.
- Close the lling valve when the pressure gauge (on the boiler)
reads between 1 and 1.5 BAR (see g. 1).
- Remove the lling loop from the connections.
3.2 HOW TO FILL THE CONDENSATE TRAP
The rst time you turn the boiler on after a prolonged period of
inactivity or for maintenance work, before using the appliance
you must ll the siphon with water and make sure that the
condensation is evacuated correctly.
Fill the condensation collection siphon pouring 1 litre of water
into the boiler combustion-analysis outlet with the boiler o󰀨,
and check that:
- the safety cut-o󰀨 device is oating
- water is owing correctly from the discharge pipe out of the
boiler
- the condensate outlet connection line is watertight
If the condensate outlet circuit (siphon and pipes) is working
3. HOW TO...
correctly, the condensation level will not exceed the maximum.
Filling the siphon before using the appliance, and the use of a
safety cut-o󰀨 device inside the siphon, prevent exhaust gases
from being released into the environment.
Repeat during standard and non-standard maintenance work.
MAX
~ 50 mm
Fig. 2a
3.3 HOW TO RESET THE APPLIANCE
When the fault code is displayed, the appliance will require to
beresetmanually.Beforeresettingtheboiler,checkwhataction
is required to be taken, using the information on the fault code
tablebelow.Allowaperiodoftwominutestoelapsebeforerotate
the mode selector knob across the position (see g. 1).

6
4.1 WHAT IF I SUSPECT A GAS LEAK
If you suspect a gas leak, turn o󰀨 the gas supply at the gas
meter and contact your installer or local gas supplier. If you
require further advice please contact your nearest Vokèra o󰀩ce.
4.2 WHAT IF I HAVE FREQUENTLY TO TOP-UP
THE SYSTEM
Ifthe systemregularly requirestopping-up, itmay beindicative
of a leak. Please contact your installer and ask him to inspect
the system.
4.3 WHAT IF THE APPLIANCE IS DUE ITS AN-
NUAL SERVICE
Advice for tenants only
Your landlord should arrange for servicing.
4. WHAT IF...
Advice for homeowners
Pleasecontact Vokèra CustomerService (0844 3910999 (UK)
or 056 7755057 (ROI) if you would prefer a Vokèra service
engineer or agent to service your appliance.Alternatively your
local GAS SAFE registered engineer may be able to service
the appliance for you.
4.4 - WHAT IF I NEED TO CALL AN ENGINEER
Ifyouthinkyourboilermayhavedevelopedafault,pleasecontact
yourinstallerorVokèraCustomerServices(08443910999(UK)
or 056 7755057 (ROI) have all your details to hand including
fulladdress and postcode,relevant contactnumbers, and your
completed appliance log book.
FAULT CODES
ALARM CODE CAUSE ALARM TYPE ACTION
_St AUTOSTOP Final Call engineer
_CL CALL FOR SERVICE Temporary then
Final Call engineer
A01
Ignition failure, ame not sensed,
internal fault, fumes exhaust - air intake
obstruction
Final Reset, check appliance operation
A02 Limit thermostat fault Final Reset, check appliance operation
A03 Fan tacho signal fault Final Reset check appliance operation,
check fan
A04 Insu󰀩cient system water pressure Final Check/rell system pressure, reset,
check appliance operation
A06 DHW thermistor fault Temporary Check DHW thermistor
A07
Primary (ow) thermistor fault Temporary Check primary thermistor, check wiring
Primary (ow) thermistor over tempe-
rature Temporary then Final Reset, check appliance operation
Temperature di󰀨erential Final Reset, check appliance operation,
check thermistors
A08
Return thermistor fault Temporary Check return thermistor, check wiring
Return thermistor over temperature Temporary then
Final Reset, check appliance operation
Temperature di󰀨erential inverted Final Reset, check pump, ensure there is
su󰀩cient circulation around heating
circuit/s
A09
Flue thermistor or ue thermistor
counter fault Temporary Check ue thermistor counter at power on, check ue thermistor, check wiring
Flue thermistor over temperature Final Reset, check appliance operation
A77 Low temperature thermostat fault Temporary Check low temperature thermostat
Adj Calibration Na None
ACO Service operation Na None
Purge cycle mode active Na None
PPreheating function active Na None
Pblinking Preheating function running Na None
Flame ON Na None
Hours Stand-by Na None
- - OFF Na None
IMPORTANT
Iftheappliancerequirestoberesetfrequently,itmaybeindica-
tiveof afault, pleasecontact yourinstaller orVokèraCustomer
Services for further advice.
3.4 HOW TO SHUT DOWN THE SYSTEM FOR
SHORT PERIODS
The system and boiler can be shut down for short periods by
simply turning the time clock to the o󰀨 position. It is also advis-
able to turn o󰀨 the main water supply to the house.
3.5 HOW TO SHUT DOWN THE SYSTEM FOR
LONG PERIODS
If the house is to be left unoccupied for any length of time –
especially during the winter – the system should be thoroughly
drained of all water. The gas, water, and electricity supply to
the house should also be turned o󰀨. For more detailed advice
contact your installer.
3.6 HOW TO CARE FOR THE APPLIANCE
To clean the outer casing use only a clean damp cloth. Do not
use any scourers or abrasive cleaners.
Fig. 3
control
valve temporary
connection
control
valve
supply pipe
double
check valve
ow/return
pipe

7
All installers are asked to follow the Benchmark Scheme by
adhering to the Code of Practise, which can be obtained from
www.centralheating.co.uk.
The Vision comprises a range of high-e󰀩ciency combination
boilers with outputs to DHW of 25kW and 29kW respectively.
Theseappliances – bydesign –incorporate electronic ignition,
circulating pump, expansion vessel, safety valve, pressure
gauge and automatic by-pass.
TheVisionrangeis producedasroom sealed,categoryII2H3P
appliances,suitableforinternalwallmountingapplicationsonly.
Each appliance is provided with a fan powered ue outlet with
an annular co-axial combustion air intake that can be rotated
– horizontally – through 360 degrees for various horizontal
or vertical applications. The Vision can also be used with the
Vokèra twin ue system.
The Vision is approved for use with C13 & C33 type ue ap-
plications.
These appliances are designed for use with a sealed system
only; consequently they are not intended for use on open
vented systems.
This booklet is an integral part of the appliance. It is therefore
necessary to ensure that the booklet is handed to the person
responsible for the property in which the appliance is located/
installed. A replacement copy can be obtained from Vokèra
customer services.
When the product reaches the end of its life it should not be
disposed of as solid urban waste but should be brought to a
separated waste collection facility.
Vision boiler complies with basic requirements of the following
Directives:
Gas Appliance Directive 2009/142/EEC until April 20th 2018
and Regulation (EU) 2016/426 from April 21st 2018;
Yielddirective:Article7(2) andAnnexIIIof directive92/42/EEC;
Electromagnetic compatibility directive 2014/30/EU;
Low-voltage directive 2014/35/EU;
Directive2009/125/EC Ecodesignforenergy-using appliances;
Directive2010/30/EU Indicationbylabelling oftheconsumption
of energy by energy-related products;
Delegated Regulation (EU) No. 811/2013;
Delegated Regulation (EU) No. 813/2013;
Delegated Regulation (EU) No. 814/2013.
At the end of its life, the product should be not be
disposed of as solid urban waste, but rather it should
be handed over to a di󰀨erentiated waste collection
centre.
Fig. 4
General layout
1. Domestic hot water heat exchanger
2. Drain valve
3. Three porte valve actuator
4. Safety valve
5. Pump
6. Bottom auto air vent (AAV)
7. Main heat exchanger
8. Flues thermistor (NTC)
9. Fan assembly with mixer
10. Silencer
11. Flue gas analysis test point
12. Flue outlet & air intake
13. Ignition transformer
14. Top AAV+De-aerator
15. Spark Electrode
16. Sensing Electrode
17. Flow thermistor (NTC)
18. High limit thermostat
19. Expansion vessel
20. Pressure switch
21. Return thermistor (NTC)
22. Atmospheric connection tube
23. Gas valve
24. Domestic hot water sensor
25. Condense trap
26. DHW ow switch
R Heating return connection
F Heating ow connection
G Gas connection
O Hot water outlet
I Cold water inlet
INTRODUCTION
INSTALLATION AND SERVICING INSTRUCTIONS
R F G O I

8
1.1 PRINCIPLE COMPONENTS
• Afullyintegratedelectroniccontrolboardfeaturingelectronic
temperature control, anti-cycle control, pump over-run, self-
diagnostic fault indicator, full air/gas modulation
• Aluminium heat exchanger
• Electronic ignition with ame supervision
• Integral high-head pump
• Fan
• Expansion vessel
• Water pressure switch
• Flue sensor
• 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:
• frost-protectionsystem–thefrost-protectionsystemprotects
the appliance against the risk of frost damage both for CH
and DHW. For CH line, if the main temperature falls to 5°C,
the appliance will function on minimum power until the tem-
perature on main reaches 35°C.
Moreover if the DHW temperature falls to 5°C, the appliance
willfunctiononminimumpoweruntilthetemperatureonmain
reaches 55°C.
• anti-blockfunction–theanti-blockfunctionenablesthepump
and divertor valve actuator to be energised for short periods,
whentheappliancehasbeeninactiveformorethan24-hours.
1.3 MODE OF OPERATION (Heating)
When there is a request for heat via the 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 circuit to ensure ame stability
at the burner. Once successful ignition has been achieved, the
electroniccircuitry increasesthegas rateto75%for aperiodof
15minutes.Thereafter,theboiler’soutputwilleitherbeincrease
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).
When the request for heat has been satised the appliance
pumpandfanmaycontinuetooperatetodissipateanyresidual
heat within the appliance.
1.4 MODE OF OPERATION (Hot water)
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
thecorrect signal voltageis receivedat thecontrol PCB.Atthis
point an ignition sequence is enabled.
Ignition is sensed by the electronic circuit to ensure ame stabil-
ity at the burner. Once successful ignition has been achieved,
the electronic circuitry increases the gas rate to maximum or
will modulate output to stabilise the temperature.
Inthe eventoftheappliance exceedingthedesired temperature
(setpoint) theburnerwill shutdownuntil thetemperaturedrops.
When the request for DHW has been satised the appliance
pumpand fanmay continuetooperate todissipate anyresidual
heat within the appliance. Fig. 5
Expansion
vessel
Safety
valve
Pump
Return
temperature
sensor
Main heat
exchanger
Bottom
AAV
Pressure
switch
DHW heat
exchanger
Diverter
valve
Drain
valve
DHW tem-
perature
sensor
Flow temperature
sensor
Top AAV
Automatic
by-pass
DHW
non return
valve
CH
return CH ow DHW
inlet
DHW
outlet
Flow regu-
lator
DHW ow
switch
SECTION 1 - DESIGN PRINCIPLES AND OPERATING SEQUENCE
1.5 SAFETY DEVICES
When the appliance is in use, safe operation is ensured by:
• awaterpressureswitchthatmonitorssystemwaterpressure
and will de-activate the pump, fan, and burner should the
system water pressure drop below the rated tolerance;
• fan speed sensor to ensure safe operation of the burner;
• ahighlimitthermostatthatover-ridesthetemperaturecontrol
circuit to prevent or interrupt the operation of the burner;
• ame sensor that will shut down the burner when no ame
signal is detected;
• ue sensor;
• a safety valve which releases excess pressure from the
primary circuit.

9
SECTION 2 - TECHNICAL DATA
2.1 Central Heating Vision 25C Vision 30C
Heat input (kW) 20.00 25.00
Maximum heat output (kW) 60/80°C 19.50 24.45
Minimum heat output (kW) 60/80°C 4.91 5.90
Maximum heat output (kW) 30/50°C 20.84 26.23
Minimum heat output (kW) 30/50°C 5.36 6.40
Minimum working pressure 0.25-0.45 bar
Maximum working pressure 2.5 bar
Minimum ow rate 350 l/h
2.2 Domestic Hot Water Vision 25C Vision 30C
Heat input (kW) 25.00 29.00
Flow Rate: ΔT35°C 10.20 11.9
Maximum inlet pressure 6 bar
Minimum inlet pressure 0.15 bar
Minimum ow rate 2 l/min
2.3 Gas Pressures Vision 25C Vision 30C
Inlet pressure (G20) 20.0 mbar 20.0 mbar
Heating maximum gas rate (m3/hr) 2.12 2.64
DHW maximum gas rate (m3/hr) 2.64 3.07
Minimum gas rate (m3/hr) 0.53 0.63
Injector size (mm) 4.8 5.1
Silencer ange (ø mm) (tted) 31 -
2.4 Fan speed (G20) Vision 25C Vision 30C
Slow ignition (rpm) 4.000 4.000
CH maximum number of fan rotation (rpm) 4.900 5.300
DHW maximum number of fan rotation (rpm) 6.100 6.200
Mimum number of fan rotation (rpm) 1.400 1.400
2.5 Expansion Vessel Vision 25C Vision 30C
Capacity 8 litres
Maximum system volume 74 litres
Pre-charge pressure 1 bar
2.6 Dimensions Vision 25C Vision 30C
Height (mm) 715
Width (mm) 405
Depth (mm) 250
Dry weight (kg) 29 29
2.7 Clearances Vision 25C Vision 30C
Sides 12mm
Top 150mm from casing or 25mm above ue elbow (whichever is applicable)
Bottom 150mm
Front 600mm
2.8 Connections Vision 25C Vision 30C
Flow & return 22mm
Gas 15mm
DHW hot & cold 15mm
Safety valve 15mm
Condense 21mm
2.9 Electrical Vision 25C Vision 30C
Power consumption (Watts) 83 89
Voltage (V/Hz) 230/50
Internal fuse 3.15AT (for PCB) - 3.15A F (for connections block)
External fuse 3A
2.10 Flue Details (concentric 60-100) Vision 25C Vision 30C
Maximum horizontal ue length (60/100mm) 5.85m 4.85m
Maximum vertical ue length (60/100mm) 6.85m 5.85m
2.10A Flue Details (concentric 80-125) Vision 25C Vision 30C
Maximum horizontal ue length (80/125mm) 15.3m 12.8m
Maximum vertical ue length (80/125mm) 20.3m 17.8m
210B Flue Details (twin pipes) Vision 25C Vision 30C
Maximum horizontal ue length (80mm/80mm) 45m/45m 40m/40m
Maximum vertical ue length (80mm/80mm) 45m/45m 40m/40m
2.11 E󰀩ciency Vision 25C Vision 30C
SEDBUK (%) 90.0 90.2
2.12 Emissions Vision 25C Vision 30C
CO2 @ maximum output (%) 9.0 9.0
CO2 @ minimum output (%) 9.5 9.5
CO @ maximum output (ppm) 180 160
CO @ minimum output (ppm) 20 20
NOx rating class 6 class 6

10
Vision 25C
Seasonal space heating energy e󰀩ciency class AWater heating energy e󰀩ciency class A
Parameter Symbol Value Unit Parameter Symbol Value Unit
Rated heat output Prated 20 kW Seasonal space heating
energy e󰀩ciency ηs 93 %
For boiler space heaters and boiler combination
heaters: useful heat output For boiler space heaters and boiler combination heaters: useful e󰀩ciency
At rated heat output and high-
temperature regime (*) P4 19,5 kW At rated heat output and high- temperature regime (*) η4 87,7 %
At 30% of rated heat output and
low-temperature regime (**) P1 6,5 kW At 30% of rated heat output and low-temperature regime (**) η1 97,8 %
Auxiliary electricity consumption Other parameters
At full load elmax 29,0 W Stand-by heat loss Pstby 40,0 W
At part load elmin 10,4 W Pilot ame energy consumption Pign - W
In Stand-by mode PSB 2,4 W Annual energy consumption QHE 53 GJ
Sound power level, indoors LWA 53 dB
Emissions of nitrogen oxides NOx 30 mg/kWh
For combination heaters:
Declared load prole XL Water heating energy e󰀩ciency ηwh 85 %
Daily electricity consumption Qelec 0,183 kWh Daily fuel consumption Qfuel 22,861 kWh
Annual electricity consumption AEC 40 kWh Annual fuel consumption AFC 17 GJ
(*) High-temperature regime means 60 °C return temperature at heater inlet and 80 °C feed temperature at heater outlet.
(**) Low temperature means for condensing boilers 30 °C, for low-temperature boilers 37 °C and for other heaters 50 °C return temperature (at heater inlet).
Vision 30C
Seasonal space heating energy e󰀩ciency class AWater heating energy e󰀩ciency class A
Parameter Symbol Value Unit Parameter Symbol Value Unit
Rated heat output Prated 24 kW Seasonal space heating
energy e󰀩ciency ηs 93 %
For boiler space heaters and boiler combination
heaters: useful heat output For boiler space heaters and boiler combination heaters: useful e󰀩ciency
At rated heat output and high-
temperature regime (*) P4 24,5 kW At rated heat output and high- temperature regime (*) η4 87,6 %
At 30% of rated heat output and
low-temperature regime (**) P1 8,1 kW At 30% of rated heat output and low-temperature regime (**) η1 97,8 %
Auxiliary electricity consumption Other parameters
At full load elmax 38,0 W Stand-by heat loss Pstby 35,0 W
At part load elmin 13,1 W Pilot ame energy consumption Pign - W
In Stand-by mode PSB 2,4 W Annual energy consumption QHE 63 GJ
Sound power level, indoors LWA 56 dB
Emissions of nitrogen oxides NOx 30 mg/kWh
For combination heaters:
Declared load prole XL Water heating energy e󰀩ciency ηwh 84 %
Daily electricity consumption Qelec 0,197 kWh Daily fuel consumption Qfuel 23,035 kWh
Annual electricity consumption AEC 43 kWh Annual fuel consumption AFC 17 GJ
(*) High-temperature regime means 60 °C return temperature at heater inlet and 80 °C feed temperature at heater outlet.
(**) Low temperature means for condensing boilers 30 °C, for low-temperature boilers 37 °C and for other heaters 50 °C return temperature (at heater inlet).

11
Key Location Minimum distance
A Below an opening (window, air-brick, etc.) 300 mm
B Above an opening (window, air-brick, etc.) 300 mm
C To the side of an opening (window, air-brick, etc.) 300 mm
D Below gutter, drain-pipe, etc. 25 mm
E Below eaves 25 mm
F Below balcony, car-port roof, etc. 25 mm
G To the side of a soil/drain-pipe, etc. 25 mm (60mm for 80/125 - 5” ue)
H From internal/external corner 25 mm (60mm for 80/125 - 5” ue)
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 ashing As determined by the xed collar
of the vertical terminal
R To the side of a boundary 300 mm
S To the side of an opening or window on a pitched roof 600 mm
T Below an opening or window on a pitched roof 2000 mm
V From a vertical terminal to an adjacent opening (window, air-brick, etc.) (call Vokera technical for advice)
W From a vertical terminal to an adjacent vertical terminal 300 mm (only if both terminals are the same hight)
Fig. 6
2.13 PUMP DUTY
Fig. 6 shows the ow-rate available – after allowing for pressure loss through the appliance – for system requirements. When
using this graph, apply only the pressure loss of the system.
Fig. 7
Flow rate (l/h)
Residual head (mbar)
00100 200300 400500 600700 800900
1100
1000
50
100
150
200
250
300
350
400
450
500
550
600

12
SECTION 3 - GENERAL REQUIREMENTS (UK)
This appliance must be installed by a competent person in ac-
cordancewith the GasSafety (Installation& Use) Regulations.
3.1 RELATED DOCUMENTS
The installation of this boiler must be in accordance with the
relevant requirements of the Gas Safety (Installation & Use)
Regulations, the local building regulations, the current I.E.E.
wiring regulations, the bylaws of the local water authority, the
Building Standards (Scotland) Regulation and Building Stand-
ards (Northern Ireland) Regulations.
It should be in accordance also with any relevant requirements
of the local authority and the relevant recommendations of the
following British 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 respect
to the installation of the appliance in a room or internal space
containing a bath or shower.
BS5440 Part1,when theterminalis 0.5metres (orless)below
plastic guttering or 1 metre (or less) below painted eaves.
3.5 AIR SUPPLY
The following notes are intended for general guidance only.
This appliance is a room-sealed, fan-ued boiler, consequently
itdoes notrequire apermanent airventfor combustionair sup-
ply. When installed in a cupboard or compartment, ventilation
for cooling purposes is also not required.
3.6 WATER CIRCULATION
Detailed recommendations are given in BS 5449 Part 1 and
BS 6798. The following notes are for general guidance only.
3.6.1 PIPEWORK
Itisrecommendedthat coppertubing toBS 2871Part1isused
in conjunction with soldered capillary joints. Where possible
pipesshouldhaveagradienttoensureairiscarriednaturallyto
air release points and that water ows naturally to drain cocks.
Except where providing useful heat, pipes should be insulated
to avoid heat loss and in particular to avoid the possibility of
freezing. Particular attention should be paid to pipes passing
through ventilated areas such as under oors, 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
These must be located in accessible positions to facilitate
draining of the appliance and all water pipes connected to the
appliance. The drain cocks must be manufactured in accord-
ance 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 lling of the system.
3.6.5 EXPANSION VESSEL
The appliance has an integral expansion vessel to accom-
modate the increased volume of water when the system is
heated. It can accept up to 8 litres of expansion from within
the system, generally this is su󰀩cient, however if the system
has an unusually high water content, it may be necessary to
provide additional expansion capacity (see 6.18).
3.6.6 FILLING POINT
A method for initial lling of the system and replacing water lost
during servicing etc. directly from the mains supply, should be
provided (see g. 8). This method of lling complies with the
current Water Supply (Water Fittings) Regulations 1999 and
Water Bylaws 2000 (Scotland). If an alternative location is
preferred, it should be connected as detailed in g. 8.
3.6.7 LOW PRESSURE SEALED SYSTEM
An alternative method of lling the system would be from an
independent make-up vessel or tank mounted in a position at
least1 metreabove thehighest pointin thesystem andat least
5 metres above the boiler (see g. 9).
The cold feed from the make-up vessel or tank must be tted
with an approved non-return valve and stopcock for isolation
purposes.Thefeed pipeshould beconnectedto thereturn pipe
as close to the boiler as possible.
When an appliance is installed in a room or internal space
containing a bath or shower, the appliance or any control per-
taining to it must not be within reach of a person using the bath
or shower. The location chosen for the appliance must permit
the provision of a safe and satisfactory ue and termination.
The location must also permit an adequate air supply for com-
bustion purposes and an adequate space for servicing and air
circulation around the appliance. Where the installation of the
appliancewillbeinanunusuallocationspecialproceduresmay
benecessary, BS6798 givesdetailed guidanceon thisaspect.
Acompartmentusedtoenclosetheappliancemustbedesigned
and constructed specically for this purpose. An existing com-
partment/cupboard may be utilised provided that it is modied
to suit. Details of essential features of compartment/cupboard
design including airing cupboard installations 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 – must be
checked to ensure that it is of adequate size to deal with the
maximum rated input of all the appliances that it serves. Instal-
lation pipes must be tted in accordance with BS 6891.
Pipework fromthe meterto theappliance mustbe ofadequate
size. Pipes of a smaller size than the appliance gas inlet con-
nection must not be used. The installation must be tested for
tightness in accordance with BS6891.
If the gas supply serves more than one appliance, it must be
ensured that an adequate supply is maintained to each appli-
ance when they are in use at the same time.
3.4 FLUE SYSTEM
Theterminalshouldbelocatedwherethedispersalofcombustion
products is not impeded and with due regard for the damage
and discoloration that may occur to building products located
nearby. The terminal must not be located in a place where it
is likely to cause a nuisance (see g. 7). In cold and/or humid
weather, water vapour will condense on leaving the terminal;
the e󰀨ect of such pluming must be considered.
If installed less than 2m above a pavement or platform to
which people have access (including balconies or at roofs)
the terminal must be protected by a guard of durable material.
The guard must be tted centrally over the terminal. Refer to
BS 5440 PART 1 FLUES
BS 5440 PART 2 FLUES & VENTILATION
BS 5449 PART 1 FORCED CIRCULATION HOT WATER SYSTEMS
BS 5546 INSTALLATION OF GAS HOT WATER SUPPLIES FOR DOMESTIC PURPOSES
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

13
This appliance must be installed by a competent person in
accordance with and dened by, the Standard Specication
(Domestic Gas Installations) Declaration (I.S. 813).
3A.1 RELATED DOCUMENTS
The installation of this boiler must be in accordance with the
relevant requirements of the local building regulations, the
current ETCI National Rules for Electrical Installations and the
bylaws of the local water undertaking.
It should be in accordance also with any relevant requirements
of the local and/or district 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
thecurrent ETCINational Rulesfor ElectricalInstallations, and
I.S. 813, Annex K.
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.
Thelocationchosenfortheappliancemustpermittheprovision
of a safe and satisfactory ue and termination. The location must
also permit an adequate air supply for combustion purposes
and 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,
refer to I.S. 813 for detailed guidance on this aspect.
A compartment used to enclose the appliance must be de-
SECTION 3A - GENERAL REQUIREMENTS (EIRE)
3.6.8 FREQUENT FILLING
Frequent lling or venting of the system may be indicative
of a leak. Care should be taken during the installation of the
appliance to ensure all aspects of the system are capable of
withstanding pressures up to at least 3 bar.
3.7 ELECTRICAL SUPPLY
Theapplianceissuppliedforoperationon230V@50Hzelectri-
calsupply; it mustbe protectedwith a 3-ampfuse.The method
of connection to the mains electricity supply must allow for
complete isolation from the supply. The preferred method is by
usingadouble-poleswitchfusedspurwithacontactseparation
of at least 3,5mm (3° high-voltage category). 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 ONACOMBUSTIBLE SURFACE
If the appliance is to be tted on a wall of combustible mate-
rial, there is no requirement for a sheet of reproof material to
protect the wall.
3.9 TIMBER FRAMED BUILDINGS
If the appliance is to be tted in a timber framed building, it
should be tted in accordance with the Institute of Gas Engineers
publication (IGE/UP/7) ‘Guide for Gas Installations in Timber
Frame Buildings’.
3.10 INHIBITORS
Vokèra recommend that an inhibitor - suitable for use with
aluminium heat exchangers - is used to protect the boiler and
system from the e󰀨ects of corrosion and/or electrolytic action.
The inhibitor must be administered in strict accordance with
the manufacturers instructions*.
*Water treatment of the complete heating system - including
the boiler - should be carried out in accordance with BS 7593
andtheDomesticWaterTreatmentAssociation’s(DWTA)code
of practice.
ow/return
pipe
control
valve
temporary
connection
control
valve
supply
pipe
double
check valve
Fig. 8
Fig. 9
Make-up vessel
or tank
Automatic
air-vent
Non-return
valve Stopcock
5.0 metres minimum
Heating
return
3.11 SHOWERS
If the appliance is intended for use with a shower, the shower
mustbe thermostaticallycontrolled andbe suitablefor usewith
a combination boiler.
signed and constructed specically for this purpose. An exist-
ing compartment/cupboard may be utilised provided that it is
modied to suit.
This appliance is not suitable for external installation.
3A.3 GAS SUPPLY
The gas meter – as supplied by the gas supplier – must be
checked to ensure that it is of adequate size to deal with the
maximum rated input of all the appliances that it serves. Instal-
lation pipes must be tted in accordance with I.S. 813.
Pipework fromthe meterto theappliance must beof adequate
size. Pipes of a smaller size than the appliance gas inlet con-
nection must not be used. The installation must be tested for
tightness in accordance with I.S. 813.
If the gas supply serves more than one appliance, it must be
ensured that an adequate supply is maintained to each appli-
ance when they are in use at the same time.
3A.4 FLUE SYSTEM
Theterminalshouldbelocatedwherethedispersalofcombustion
products is not impeded and with due regard for the damage
and discoloration that may occur to building products located
nearby. The terminal must not be 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 e󰀨ect of such pluming must be
considered.
If installed less than 2m above a pavement or platform to
which people have access (including balconies or at roofs)

14
the terminal must be protected by a guard of durable material.
The guard must be tted centrally over the terminal. Refer to
I.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.
This appliance is a room-sealed, fan-ued boiler, consequently it
doesnotrequireapermanentairventforcombustionairsupply.
When installed in a cupboard or compartment, ventilation for
cooling purposes is also not required.
3A.6 WATER CIRCULATION
Specic recommendations are given in I.S. 813. The following
notes are for general guidance only.
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 ensure air
is carried naturally to air release points and that water ows
naturally to drain cocks.
Except where providing useful heat, pipes should be insulated
to avoid heat loss and in particular to avoid the possibility of
freezing. Particular attention should be paid to pipes passing
through ventilated areas such as under oors, 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 lling of the system.
3A.6.5 EXPANSION VESSEL
The appliance has an integral expansion vessel to accom-
modate the increased volume of water when the system is
heated. It can accept up to 8 litres of expansion from within
the system, generally this is su󰀩cient, however if the system
has an unusually high water content, it may be necessary to
provide additional expansion capacity (see 6.18).
3A.6.6 FILLING POINT
A method for initial lling of the system and replacing water
lost during servicing etc. should be provided (see g. 8). You
should ensure this method of lling complies with the local water
authority regulations.
3A.6.7 LOW PRESSURE SEALED SYSTEM
An alternative method of lling 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 g. 9). The cold feed from
the make-up vessel or tank must be tted with an approved
non-returnvalve andstopcock forisolation purposes.Thefeed
pipe should be connected to the return pipe as close to the
boiler as possible.
3A.6.8 FREQUENT FILLING
Frequent lling or venting of the system may be indicative
of a leak. Care should be taken during the installation of the
appliance to ensure all aspects of the system are capable of
withstanding pressures up to at least 3 bar.
3A.7 ELECTRICAL SUPPLY
Theapplianceissuppliedforoperationon230V@50Hzelectri-
calsupply; it mustbe protectedwith a 3-ampfuse.The method
of connection to the mains electricity supply must allow for
complete isolation from the supply. Thepreferred method is by
using a double-pole switch fuse spur with a contact separation
of at least 3,5 mm (3° high-voltage category). The switch must
only supply the appliance and its corresponding controls, i.e.
time clock, room thermostat, etc.
3A.8MOUNTINGONACOMBUSTIBLESURFACE
If the appliance is to be tted on a wall of combustible mate-
rial, there is no requirement for a sheet of reproof material to
protect the wall.
3A.9 TIMBER FRAMED BUILDINGS
If the appliance is to be tted in a timber framed building, it
should be tted 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 Frame Buildings’ gives specic
advice on this type of installation.
3A.10 INHIBITORS
Vokèra recommend that an inhibitor - suitable for use with
aluminium heat exchangers - is used to protect the boiler and
system from the e󰀨ects of corrosion and/or electrolytic action.
The inhibitor must be administered in strict accordance with
the manufacturers instructions*.
*Water treatment of the complete heating system - including
the boiler - should be carried out in accordance with I.S. 813
andtheDomesticWaterTreatmentAssociation’s(DWTA)code
of practice.
3A.11 SHOWERS
If the appliance is intended for use with a shower, the shower
mustbe thermostaticallycontrolled andbe suitablefor usewith
a combination boiler.
3A.12 DECLARATION OF CONFORMITY
A Declaration of Conformity (as dened 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.

15
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 oor with the writing the correct way up.
4.2 CONTENTS
Contained within the carton is:
• the boiler
• the wall bracket
• carton template
• anaccessoriespackcontainingapplianceserviceconnections
and washers
• theinstructionpackcontainingtheinstallation,servicing&user
instructions, guarantee registration card and a 3-amp fuse.
4.3 UNPACKING
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,
carefullyremoveallprotectivepackagingfromtheapplianceand
lay the accessories etc. to one side. Protective gloves should
be used to lift the appliance, the appliance back-frame should
be used for lifting points.
4.4 PREPARATION FOR MOUNTING THE AP-
PLIANCE
The appliance should be mounted on a smooth, vertical sur-
face, which must be capable of supporting the full weight of
theappliance. Careshould beexercised whendeterminingthe
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 g. 10) and ue-hole (if applicable).
Fig. 10
A
4.5 FITTING THE FLUE
This appliance incorporates a ‘click-t’ ue connection at the top
of the appliance, and also incorporates a rear-ue connection.
Should the rear-ue connection be preferred, the ue outlet will
require to be re-congured from a top outlet to a rear outlet.
Please refer to section 4.5.1.2 and the instructions supplied
with the rear-ue kit (code 20132064) on how to re-congure
the ue outlet and how to install the rear-ue terminal.
4.5.1 CONCENTRIC HORIZONTAL FLUE
Reduction for additional bends
Bend Reduction in maximum ue length for each bend
45º bend 1.0 metre
90º bend 1.0 metre
Horizontal ue terminals and accessories
Code Description Length
20122759 XF Fixed Length Horizontal Flue kit TBC
20122761 XT Telescopic Horizontal Flue Kit TBC
20132059 90-degree bend N/A
20132058 45-degree bends (2) N/A
20132060 0.5-Metre Extension 500mm
20132061 1.0-Metre Extension 1000mm
20132062 2.0-Metre Extension 2000mm
20131979 Telescopic extension 372/519mm
20132064 Rear-ue kit TBC
522 Plume management kit 1370mm
20135587 Wall Brackets N/A
Using the template provided (A), mark and drill a 125mm hole
for the passage of the ue pipe. Each horizontal terminal,
incorporates an incline on the inner (60mm) pipe; this enables
the terminal to be installed on a level plane. However any
extended horizontal ue runs must incorporate a 3-degree fall-
back from the ue terminal towards the appliance. The xing
holes for the wall-mounting bracket should now be drilled and
plugged, an appropriate type and quantity of xing 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. 11
ange installed
as standard
AA
C
B
90° bend
C
FITTING THE HORIZONTAL FLUE KIT
Carefully measure the distance from the centre of the appliance
ue outlet to the edge of the nished outside wall (dimension X).
Add 65mm to dimension X to give you Dimension Y (see g. 12).
Measure dimension Y from the terminal end of the concentric
ue pipe and cut o󰀨 the excess ensuring any burrs are removed.
IMPORTANT: The X-type ue terminals are supplied with
a sachet of silicone lubricant; smear a small amount of the
lubricant around both inner and outer connections, at both
ends of the ue bend.
NOTE: Attach the decorative white plastic trim to the ue pipe
at this point if it’s required.
Attach the ue bend to the ueterminalensuringthatbothpipes
are fully inserted into the ue bend. Insert the assembled ue
terminal and bend into the pre-drilled hole and o󰀨er up the ue
bend to the appliance ue spigot.
NOTE: The appliance incorporates a ‘click-t’ ue connection
(see g. 11). Ensure that both screws ‘C’ on the ‘click-t’ have
been slackened o󰀨. Ensure that the bend is correctly aligned
with the connector and insert the ue bend into the connector
until it clicks into position (this is when the tabs at points ‘A’
are located in the groove of the ue bend - see g. 11). Both
screws (C) should now be tightened.
NOTE: If more convenient, the ue bend can be attached to the
SECTION 4 - INSTALLATION

16
appliance before connecting it to the ue terminal.
NOTE: Ensure that the outlet of the ue terminal is correctly
orientated as shown in g. 12.
NOTE
You must ensure that the entire ue system is properly supported
and connected. Seal the ue assembly to the wall using
cement or a suitable alternative that will provide satisfactory
weatherproong. The exterior trim can now be tted.
Fig. 12
Fig.13
A
EXTENDING THE FLUE
Connect the bend - supplied with the ue terminal - to the
appliance ‘click-t’ connector.
IMPORTANT: The X-type ue terminals are supplied with
a sachet of silicone lubricant; smear a small amount of the
lubricant around both inner and outer connections, at both
ends of the ue bend.
NOTE: The appliance incorporates a ‘click-t’ ue connection
(see g. 12). Ensure that both screws ‘C’ (g. 11) on the ‘click-
t’ have been slackened o󰀨. Ensure that the bend is correctly
aligned with the connector and insert the ue bend into the
connector until it clicks into position (this is when the tabs at
points ‘A’ are located in the groove of the ue bend - see g.
11). Both screws (C) should now be tightened. The additional
bends & extensions have push-t connections, care should be
taken to ensure that the correct seal is made when assembling
the ue system. Connect the required number of ue extensions
or bends (up to the maximum equivalent ue length) to the ue
terminal (see g. 11-14). The ue system should have a 3º rise
from the boiler to outside, to ensure any condense uid that
forms, is allowed to drain back to the appliance.
NOTE
When cutting an extension to the required length, you must
ensurethat theexcess iscutfrom theplain endofthe extension
(see g. 11-14). Remove any burrs, and check that all seals are
located properly. You must ensure that the entire ue system is
properly supported and connected. Seal the ue assembly to
the wall using cement or a suitable alternative that will provide
satisfactory weatherproong. The interior and exterior trim can
now be tted.
4.5.1.2 FITTING THE REAR FLUE (g. 16) (rear ue outlet
only)
Refer to g. 16 & 17 and the instructions supplied with the rear-
ue kit (code 29450133) for details on how to re-congure the
appliance from a top outlet to a rear outlet.
Using the template provided, mark and drill a 125mm hole
for the passage of the ue pipe. The hole should be drilled
LEVEL as the terminal already incorporates a fall-back to
the appliance. The xing holes for the wall-mounting bracket
should now be drilled and plugged, an appropriate type and
quantity of xing should be used to ensure that the bracket is
mounted securely. Once the bracket has been secured to the
wall, attach the rear ue terminal to the appliance (using the
previously retained screws) and x the telescopic terminal to
the correct length (wall thickness) ensuring that the terminal
will protrude through the wall by the correct distance.
Once the terminal has been adjusted to the correct length,
ensure that the ue outlet is orientated to the correct position,
and then insert the xing screw (supplied) and attach the
sealing strip (supplied) at the ue joint.
NOTE: If required the telescopic section that incorporates the
ue outlet can be trimmed to reduce its length.
NOTE: The inner 60mm pipe of the rear ue terminal must
be cut by 8mm at the point indicated (g. 15 pos. A).
At this point, lift the appliance and carefully insert the terminal
into and through the wall, ensuring that the wall bracket
engages with the corresponding holes at the top of the
appliance.
A:cutting 8mm
pre-shearing
Fig.15
When reconguring the outlet from a top to a rear outlet, it is
necessary to remove the ‘click-t’ connector; replace all but
one of the securing screws - using the remaining screw to
secure the top outlet cap (g. 16).
When removing the rear outlet cap; retain the 4-screws as
these are required to attach the rear-ue terminal to the
appliance (g. 17).
Fig.14

17
Fig.16
Fig.17
Seal the ue assembly to the wall using cement or a suitable
alternative that will provide satisfactory weatherproong. The
exterior wall trim can now be tted.
Part No. Description Length
20132064 Rear ue terminal 825mm
4.5.2 CONCENTRIC VERTICAL FLUE
Using g. 18 as a reference, cut a 110mm diameter hole in
the roof and/or ceiling to facilitate the route of the vertical ue
system. NOTE: ensure that the top of the appliance - if already
inposition -is coveredand protectedfromthe possibilityof any
dust or debris falling or entering the appliance via the ue outlet.
Fit the appropriate ashing to the roof and insert the vertical ue
terminal through the ashing from outside, ensuring that the
collar of the terminal is located over the outlet of the ashing.
The xing holes for the appliance wall mounting bracket should
now be drilled and plugged. An appropriate type and quantity
of xing should be used to ensure that the bracket is mounted
securely.Oncethebrackethasbeensecuredtothewall,mount
the appliance onto the bracket.
If the vertical ue system requires additional extensions or bends,
connect these to the vertical terminal, ensuring the following:
- the maximum permitted ue length is not exceeded
- reductions to the maximum ue length have been made for
any bends that are used on the vertical ue system
- any horizontal sections of the ue system, incorporate a
3-degree fallback to the appliance
- the entire ue system is fully supported and secured using
the appropriate brackets
- if/when an extension is cut to a shorter length, ensure that
the excess length is cut from the plain end of the extension,
and that any burrs or rough edges are removed
- allsealsareproperlylocatedbeforeassemblingorconnecting
the ue system.
IMPORTANT: The VX ue terminal is supplied with a sachet of
siliconelubricant;smearasmallamountofthelubricantaround
both inner and outer connections, at both ends of the vertical
ue connector (supplied with the VX terminal).
NOTE: The appliance incorporates a ‘click-t’ ue connection
(see g. 18. Ensure that both screws ‘C’ on the ‘click-t’ have
been slackened o󰀨. Ensure that the connector is correctly aligned
with the ‘click-t’ and insert it into the ‘click-t’ until it clicks into
position (this is when the tabs at points ‘A’ are located in the
groove of the vertical ue connector - see g. 18). Both screws
(C) should now be tightened.
NOTE: If more convenient, the vertical ue connector can be
attached to the vertical ue terminal/extension before connecting
it to the appliance.
NOTE
Additional bends and/or extensions can be connected to the
terminal connector if desired, however if additional bends are
tted, a reduction must be made to the maximum ue length
(see table below).
vertical
connection
A
A
C
C
B
ange installed
as standard Fig.18
Reduction for bends
Bend Reduction in maximum ue length for each bend
45º bend 1.0 metre
90º bend 1.0 metre
Vertical ue terminal and accessories
Code Description Length
20122763 XV vertical Flue kit 1000mm
20132050 Pitched Roof Flashing N/A
20135582 Flat Roof Flashing N/A
20132059 90-Degree Bend N/A
20132058 45-Degree Bend x 2 N/A
20132060 0.5-Metre Extension 500mm
20132061 1.0-Metre Extension 1000mm
20132062 2.0-Metre Extension 2000mm
20131979 Telescopic Extension 372/519mm
20135585 Wall Brackets N/A

18
Fig. 19
IMPORTANT
The vertical ue terminal is 1.0 metre in length and cannot be
cut; therefore it may be necessary to adjust the height of the
appliance to suit or use a suitable extension.
Fig. 20
RTN FLOW GAS HOT COLD