Riello Vokera VISION PLUS 35 C G. C. Release note

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 PLUS
High efciency combi boiler
VISION PLUS 35 C G.C. N° 47-364-54
VISION PLUS 40 C G.C. N° 47-364-55

2
1.1A GAS APPLIANCES 3
1.2A ELECTRICAL SUPPLY 3
1.3A WARRANTY REGISTRATION 3
1.4A APPLIANCE COMMISSIONING CHECKLIST (UK ONLY) 3
1.5A HOW DOES IT WORK? 3
1.6A DIMENSION 3
1.7A CLEARANCES REQUIRED 3
1.8A FROST PROTECTION SYSTEM 3
1.9A CONTROL PANEL 4
2a GETTING STARTED 5
2.1A PARAMETERS ACCESS 5
2.2A PROGRAMMING THE BOILER 5
2.3A OPERATING MODE 6
2.4A OTBus REMOTE CONTROL CONNECTION 7
2.5A BOILER FAULT CODES 8
2.6A INFO MENU 8
3a HOW TO... 9
3.1A HOW TO TOP-UP THE SYSTEM PRESSURE 9
3.2A HOW TO RESET THE APPLIANCE 9
3.3A HOW TO SHUT DOWN THE SYSTEM FOR SHORT PERIODS 9
3.4A HOW TO SHUT DOWN THE SYSTEM FOR LONG PERIODS 9
3.5A HOW TO CARE FOR THE APPLIANCE 9
3.6A KEYBOARD LOCKOUT FUNCTION 9
4a WHAT IF... 10
4.1A WHAT IF I SUSPECT A GAS LEAK 10
4.2A WHAT IF I HAVE FREQUENTLY TO TOP-UP THE SYSTEM10
4.3A WHAT IF THE APPLIANCE IS DUE ITS ANNUAL SERVICE 10
4.4A WHAT IF I NEED TO CALL AN ENGINEER 10
3.7A INTERFACE STAND BY 10
1 INTRODUCTION 11
2 DESIGN PRINCIPLES AND OPERATING SEQUENCE 12
2.1 PRINCIPLE COMPONENTS 12
2.2 MODE OF OPERATION (AT REST) 12
2.3 MODE OF OPERATION (HEATING) 12
2.4 MODE OF OPERATION (HOT WATER) 12
2.5 SAFETY DEVICES 12
2.6 TECHNICAL DATA 13
2.7 PUMP DUTY 15
2.8 HOW TO FREE THE PUMP 15
3 GENERAL REQUIREMENTS (UK) 16
3.1 RELATED DOCUMENTS 16
3.2 LOCATION OF APPLIANCE 16
3.3 GAS SUPPLY 16
3.4 FLUE SYSTEM 16
3.5 AIR SUPPLY 16
3.6 WATER CIRCULATION 16
3.7 ELECTRICAL SUPPLY 17
3.8 MOUNTING ON A COMBUSTIBLE SURFACE 17
3.9 TIMBER FRAMED BUILDINGS 17
3.10 WATER TREATMENT 17
3.11 SHOWERS 17
3E GENERAL REQUIREMENTS (EIRE) 17
3.1E RELATED DOCUMENTS 17
3.2E LOCATION OF APPLIANCE 17
3.3E GAS SUPPLY 18
3.4E FLUE SYSTEM 18
3.5E AIR SUPPLY 18
3.6E WATER CIRCULATION 18
3.7E ELECTRICAL SUPPLY 18
3.8E MOUNTING ON A COMBUSTIBLE SURFACE 18
3.9E TIMBER FRAMED BUILDINGS 18
3.10E WATER TREATMENT 18
3.11E SHOWERS 18
3.12E DECLARATION OF CONFORMITY 18
4 INSTALLATION 19
4.1 PREPARATION FOR MOUNTING THE APPLIANCE 19
4.2 FITTING THE FLUE 19
4.3 CONNECTING THE GAS AND WATER (“FIG. 18”) 21
4.4 INSTALLATION OF CONDENSATE DRAIN PIPE 21
4.5 I NSTRUCTION FOR CONDENSATION EXHAUST CONNECTION 22
4.6 ELECTRICAL CONNECTIONS 22
4.7 CASING REMOVAL 22
4.8 CONNECTING THE MAINS (230V) INPUT 22
5 OPERATION 23
5.1 ACCESS TO THE PARAMETERS 23
5.2 CONTROL PANEL 23
5.3 SETTINGS MENU TREE STRUCTURE 24
5.4 STARTING THE BOILER 25
5.5 BOILER CONFIGURATION 26
5.6 FIRST COMMISSIONING 28
5.7 VENT CYCLE 28
5.8 OPERATING STATUS 28
6 COMMISSIONING 31
6.1 GAS SUPPLY INSTALLATION 31
6.2 THE HEATING SYSTEM 31
6.3 INITIAL FILLING OF THE SYSTEM 31
6.4 PRE-OPERATION CHECKS 31
6.5 INITIAL LIGHTING 31
6.6 CHECKING GAS PRESSURE AND COMBUSTION ANALYSIS 31
6.7 FINAL FLUSHING OF THE HEATING SYSTEM 31
6.8 SETTING THE FLOW OUTLET TEMPERATURE 31
6.9 SETTING THE SYSTEM DESIGN PRESSURE 31
6.10 REGULATING THE CENTRAL HEATING SYSTEM 32
6.11 FINAL CHECKS 32
6.12 INSTRUCTING THE USER 32
7 SERVICING INSTRUCTIONS 32
7.1 GENERAL 32
7.2 ROUTINE ANNUAL SERVICING 32
7.3 CLEANING THE PRIMARY HEAT EXCHANGER 33
7.4 CLEANING THE BURNER 33
7.5 CLEANING THE SIPHON 33
7.6 ELECTRODES VERIFICATION 33
7.7 CLAPET 33
7.8 REPLACEMENT OF COMPONENTS 33
7.9 COMPONENT REMOVAL PROCEDURE 33
7.10 CASING REMOVAL (Fig. 26) 34
7.11 PUMP ASSEMBLY (Fig. 27) 34
7.12 SAFETY VALVE (Fig. 28) 34
7.13 LOWER ATOMATIC AIR RELEASE VALVE (Fig. 27) 34
7.14 WATER PRESSURE TRANSDUCER (Fig. 29) 34
7.15 DHW THERMISTOR (Fig. 29) 34
7.16 FLOW THERMISTOR (FIG. 3 - POS. 7) 34
7.17 RETURN THERMISTOR (FIG. 3 - POS. 21) 34
7.18 PRINTED CIRCUIT BOARD (FIG. 30) 34
7.19 GAS VALVE (FIG. 31) 35
7.20 ELECTRODES (FIG. 32) 35
7.21 EXPANSION VESSEL (FIG. 33) 35
7.22 HEAT EXCHANGER (FIG. 34) 35
7.23 COMBUSTION UNIT (FIG. 36) 36
7.24 FAN AND MIXER (FIG. 37) 36
7.25 DIVERTER VALVE ASSEMBLY (FIG. 38) 36
7.26 REMOVING THE SIPHON (FIG. 39) 37
7.27 REPLACING INTERFACE 37
7.28 REPLACING PCB OR INTERFACE 37
8 CHECKS, ADJUSTMENTS AND FAULT FINDING 38
8.1 CHECKING APPLIANCE OPERATION 38
8.2 APPLIANCE MODES OF OPERATION 38
8.3 CHECKING THE CO2AND ADJUSTING THE GAS VALVE 38
8.4 CHECKING THE EXPANSION VESSEL 39
8.5 EXTERNAL FAULTS 39
8.6 ELECTRICAL CHECKS 40
8.7 FAULT FINDING 40
8.8 COMPONENT VALUES & CHARACTERISTICS 40
8.9 ADJUSTMENTS 40
8.10 GAS VALVE CALIBRATION 41
8.11 RANGE RATED 41
8.12 SETTING THE THERMOREGULATION 41
8.13 LIGHTS AND FAULTS 42
8.14 BOILER FAULT CODES 43
8.15 INFO MENU 44
8.16 EMBEDDED CLOCK 45
8.17 CLOCK FUNCTIONALITY 45
8.18 PROGRAMMING THE EMBEDDED CLOCK 45
9 WIRING DIAGRAMS 46
9.1 EXTERNAL WIRING 46
9.2 OTHER DEVICES 46
9.3 OTBUS CONNECTION 46
10 LPG INSTRUCTIONS 48
10.1 RELATED DOCUMENTS 48
10.2 TECHNICAL DATA 48
10.3 GAS CONVERSION 48
10.4 COMPLETION 48

3
1.1A 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.
1.2A ELECTRICAL SUPPLY
Please ensure that this appliance has been properly connected
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!
1.3A WARRANTY REGISTRATION
The appliance warranty can be registered online or by contact-
ing our warranty registration helpline using the contact number
displayed on the registration label on the front of your appliance.
1.4A APPLIANCE COMMISSIONING
CHECKLIST (UK ONLY)
A checklist section can be found at the rear of the appliance
installation booklet. This important document must be
completed 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
recorded 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 affect your statutory rights.
1.5A HOW DOES IT WORK?
Your VISION PLUS boiler supplies heated water to your radiators
and hot water to your hot water taps. The central heating and
hot water are controlled 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 PLUS 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.
1.6A DIMENSION
VISION PLUS 35C - 40C
HEIGHT 740 mm
WIDTH 420 mm
DEPTH 350 mm
1.7A CLEARANCES REQUIRED
ABOVE 100mm*
BELOW 200mm^
LEFT SIDE 2mm
USERS INSTRUCTIONS
Dear Customer
Your Vokèra VISION PLUS 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 ef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.
This booklet is an integral part of the appliance. It is therefore necessary to ensure that the booklet is handed to the person re-
sponsible for the property in which the appliance is located/installed. A replacement copy can be obtained from the Vokera website.
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 differentiated waste collection centre .
INTRODUCTION
1A THINGS YOU SHOULD KNOW
RIGHT SIDE 2mm**
FRONT 4mm***
* 100mm if rear-ue outlet is used or 25mm above ue bend if top ue
outlet is used. Consideration should be given to providing reasonable
clearance for the insertion of a FGA probe.
** Disconnection of adjacent components may be required in order to
facilitate syphon removal.
*** Provided that a door or removal panel enables 450mm access for
maintenance.
^ Can be reduced to 5mm if a removal panel enables 200mm for
maintenance.
1.8A
200
25
22
100
FROST PROTECTION SYSTEM
The VISION PLUS is equipped with a built-in frost protection
system, this enables the boiler to over-ride the time controls
– even if switched off – 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
protection be required for the heating system, additional
controls may be required.
NOTE
The frost protection system is reliant on the appliance having a
permanent electrical supply, and being in a non-fault condition.

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A
It is normally used to raise the domestic hot water tem-
perature, when the arrow is highlighted it has the
conrm function
BIt is normally used to lower the domestic hot water tem-
perature, when the arrow is highlighted it has the
back/cancel function
A+B Access to the domestic hot water comfort functions
(see paragraph “2.3.9a DOMESTIC HOT WATER
COMFORT FUNCTION”)
CIt is normally used to raise the heating water
temperature, when the arrow is highlighted you
can move inside the P1 menu
DIt is normally used to lower the heating water
temperature, when the arrow is highlighted you
can move inside the P1 menu
A+C Access to the menu for setting the clock (see para-
graph “2.2a PROGRAMMING THE BOILER”)
1Used to change the operating status of the boiler (OFF,
SUMMER and WINTER)
2Used to reset the alarm status or to interrupt the vent
cycle
3
Used to access the INFO and P1 menus. When the
icon
Enter
is shown on the display, the key has the
ENTER function and is used to conrm the value set
during the programming of a technical parameter
1+3 Lock and unlock keys
2+3 When the boiler is set to OFF it is used to start the
combustion analysis function (CO)
Indicates the connection to a remote device (OT or
RS485)
Indicates the connection to a WIFI device
Indicates the presence of an outdoor temperature
sensor
Indicates the activation of special domestic hot water
functions or the presence of a system for managing
the solar thermal array
Indicates the connection to a heat pump (not used on
this model)
Displayed when a fault occurs and/or when there is
an alarm
Fault and/or service indicator
Indicates the presence of a ame, in the event of a
ame lockout the icon looks like
Reset
It comes on when there are alarms that require a
manual reset by the user
Enter
It comes on when there is an operation conrmation
request
When the icon is active, it indicates that the "conrm”
function of button Ais active
When the icon is active, it indicates that the "back/
cancel” function of button Bis active
When the icon is active, it is possible to navigate the
menu or raise the value of the selected parameter
When the icon is active, it is possible to navigate the
menu or lower the value of the selected parameter
The icon comes on if central heating is active, it
blinks if a heating request is in progress
The icon comes on if domestic hot water is active, it
blinks if a domestic hot water request is in progress
They indicate the set point level set (1 bar minimum
value, 4 bars maximum value)
1 2 3 4 5 6 7 Indicates the days of the week
AUTO
ON Only if clock is enabled
MAN ON Only if clock is enabled
MAN OFF Only if clock is enabled
The remote control has the function of a machine interface, displaying the system settings and providing access to the parameters.
The display normally shows the temperature of the ow sensor unless there is a domestic hot water request in progress, then the
domestic hot water probe temperature is displayed; if no key is touched within 10 sec the current time is displayed (backlight unlit).
The conguration MENU is organised with a multi-level tree structure. An access level has been xed for each sub-menu: USER level
always available; TECHNICAL level password protected.
1.9A CONTROL PANEL
Your boiler is equipped with a large LCD display that indicates the
appliance operating status.
Fig. 1
RESET
+
MENU
+
AACC
1 2 31 2 3
BBDD

5
2A GETTING STARTED
2.1A PARAMETERS ACCESS
Pressing the MENU key for at least 2 sec provides access to the
P1 menu, allowing the parameters to be programmed.
If the case the menu is empty, P8.04 is displayed, otherwise the
rst item in the menu appears.
IMPORTANT
The parameters dedicated to the user are the following:
Menu Parameters
Scrolling message
only if parameter
P1.05 = 1
Value Password
level
P1 SETTINGS
P1.01 LANGUAGES
0 IT
1 RO
2 FR
3 EN
4 SR
5 HR
6 ES
7 EL
8 BG
9 PL
10 SL
USER
P1.02 TIME USER
P1.03 TIME PROGRAM Only if clock is
enabled - see 8.16
P1.05 SCROLLING 0 / 1 USER
P1 (SETTINGS menu)
P1.01
Select the parameter to set the desired language (see above table).
P1.02
From this menu the time and the number of the day of the week can be
adjusted.
P1.03
Available only if embedded clock has been enabled.
P1.05
This parameter allows you to enable scrolling text after the parameter
code itself:
0= OFF
1= ON
2.2A PROGRAMMING THE BOILER
Ensure the gas and electrical supplies to the appliance are
switched on.
With power on the backlight comes on, then all the icons and
the segments come on for 1sec and in sequence the rmware
revision is displayed for 3sec:
Then the interface displays the status active at that moment.
If necessary, the interface automatically goes to the clock menu.
On the main screen the icons , , and and ENTER
come on while 00:00 is displayed with the rst two digits blinking
with a frequency of 0.5 sec ON, 0.5 sec OFF.
To set the time and day proceed as follows:
set the hour with the and arrows, then conrm with A
set the minutes with the and arrows, then conrm with A
set the day of the week with the and arrows. The
segment of the day selected blinks, press MENU at the icon
Enter
per to conrm the time and day setting. The clock blinks
for 4sec and then returns to the main screen
to exit the time programming without saving the modied values,
just press .
NOTE: It is possible to change the TIME and DAY settings also
later by accessing the P1.02 parameter in the P1 menu, or by
pressing the A+C keys for at least 2sec.
RESET
+
MENU
+C
A
If you need to set the language, select the menu P1 and conrm
your choice using .
Use the arrows to display parameter P1.01, then enter the submenu
by pressing .
Use the and buttons to set the desired language – see
“2.1a PARAMETERS ACCESS” . To conrm your choice, press
Enter
.

6
Vent cycle
Whenever the electrical supply to the appliance has been
disrupted (OFF) and then restored (ON), it will enter a 4-min
vent cycle.
b When the air purging cycle is in progress, all heat
requests are inhibited except those for domestic hot
water when the boiler is not set to OFF and -AIR is
displayed on the interface screen.
The display shows the message -AIR lighting up the icon
RESET.
The purge cycle can be interrupted early by keeping key 2
(the icon RESET comes on). The purge cycle can also be
interrupted, if the boiler is not set to OFF, by a domestic hot
water request.
Adjust the ambient temperature thermostat to the desired
temperature (~20°C) or, if the system is equipped with a
programmable thermostat or timer, ensure that the thermo-
stat or timer is “active” and set correctly (~20°C)
Then set the boiler on WINTER or SUMMER depending on
the type of operation desired.
The boiler will start up and continue working until the set
temperatures are reached, after which it will then go back
to standby.
2.3A OPERATING MODE
For changing the operating status from WINTER to SUMMER
to OFF press key 1 until the icon for the desired function is
displayed.
2.3.1A WINTER MODE
Set the boiler to the WINTER status by pressing key 1 until
both the domestic hot water icon and the heating icon are
displayed.
The interface normally displays the delivery temperature
unless there is a domestic hot water request in progress, in
which case the domestic hot water temperature is displayed.
When there is a heat request and the burner is lit, the icon
appears on the display.
Heating REQUEST, the radiator icon blinks:
Bar
2.3.2A SUMMER MODE
Set the boiler to the SUMMER status by pressing key 1
until the domestic hot water icon is displayed.
In this status the boiler activates the traditional function of
just domestic hot water, the interface normally displays the
delivery temperature. In the event of a domestic hot water pick
up, the display shows the temperature of the domestic hot
water.
Domestic hot water REQUEST, the tap icon blinks:
DAY
2.3.3A OFF
Set the boiler to the OFF status by pressing key 1 until the
central segments are displayed.
2.3.4A ADJUSTING THE HEATING WATER
TEMPERATURE WITHOUT AN OUTDOOR
TEMPERATURE SENSOR CONNECTED
If there is no outdoor temperature sensor the boiler operates
at a xed point, the HEATING setpoint in this case can be set
on the main page of the screen.
The successive pressing of the key Cor Don the main screen
displays the current value of the heating setpoint; the value
blinks with a frequency of 0.5 sec ON, 0.5 sec OFF and the
icons and come on.
RESET
+
MENU
+
D
C
The succes sive pressing of the key Cor Dallows you to set the
value of the heating setpoint within the preset range:
[40°C - 80.5°C] for high temperature systems
[20°C - 45 °C] for low temperature systems
with steps of 0.5°C. The level bars beside the heating icon
show the setpoint value set with respect to the operating range:
- four bars on = m ax setpoint
- one bar on = min setpoint
Keeping one of the two keys Cor Dpressed for longer, the
meter increases the speed of advancement modifying the set
value. If no key is pressed for 5sec, the value set is taken as
the new heating setpoint and the display returns to the main
page.

7
2.3.5A ADJUSTING THE HEATING WATER
TEMPERATURE WITH AN OUTDOOR
TEMPERATURE SENSOR CONNECTED
If an outdoor temperature sensor is installed and thermoregu-
lation is enabled (parameter P4.18=1), the delivery tempera-
ture is automatically selected by the system, which quickly
adjusts the ambient temperature according to the variations in
the outdoor temperature.
If you want to change the temperature, raising it or lowering it
with respect to that automatically calculated by the electronic
board, it is possible to change the HEATING setpoint selecting
the desired comfort level within the range (-5 - +5).
Note: if an outdoor temperature sensor is connected it is in
any event possible to have the boiler operate at a xed point
by setting the parameter P4.18 = 0 (menu P4).
2.3.6A ADJUSTING THE DOMESTIC HOT WATER
TEMPERATURE
On the main screen, pressing the key Arather than Bdisplays
the current domestic hot water setpoint, the value blinks with a
frequency of 0.5 sec ON, 0.5 sec OFF and the icons and
come on.
A
RESET
+
MENU
+
B
The successive pressing of the keys Aor Ballows you to set
the value of the domestic hot water setpoint raising or lowering
the value within the preset range in steps of 0.5°C. The level
bars beside the heating icon show the setpoint value set with
respect to the operating range:
- four bars on = max setpoint
- one bar on = min setpoint
2.3.7A SAFETY STOP
If there are ignition faults or boiler operation malfunctions,
carry out a “SAFETY STOP”. On the display, in addition to the
fault code, the icon is also displayed, which blinks with a
frequency of 0.5sec ON and 0.5sec OFF.
The backlight blinks for 1min after which it switches off, while
the icon continues blinking.
On the 4 digits a message scrolls containing the error code
and its description.
DAY
2.3.8A RESET FUNCTION
The “RESET” icon comes on when there is an alarm that
requires a manual reset by the user (for example ame
lockout). To reset the lockout press key 2 RESET.
DAY
RESET
If the reset attempts do not restart the boiler, contact you en-
gineer or Vokera Ltd. for help or advice.
2.3.9A DOMESTIC HOT WATER COMFORT FUNCTION
Pressing the keys A+B for at least 2sec gives you access to
the domestic hot water comfort functions. COFF is shown on
the display and the icons , , and come on:
Using the keys , you can scroll through the options
in sequence CSTD and then COFF again. Using the key
activates the desired function and you exit the menu returning
to the initial screen. A scrolling message appears on the
display with the following mode:
Function Scrolling message
CSTD COMFORT STANDARD
COFF COMFORT OFF
CSTD (PREHEATING function)
By setting CSTD, the domestic hot water preheating function
of the boiler activates. This function keeps the water in the
domestic hot water exchanger hot, to reduce standby times
when a request is made. When the preheating function is
enabled the scrolling message PREHEATING FUNCTION
IN PROGRESS is displayed. To deactivate the preheating
function set COFF. The function is not active when the boiler
is OFF.
2.4A OTBus REMOTE CONTROL
CONNECTION
When an OTBus remote control is connected to the system,
the boiler display shows the following screen:
In particular on the boiler display:
it is no longer possible to set the boiler OFF/WINTER/
SUMMER status (it is set by the OTBus remote control)
it is no longer possible to set the domestic hot water
setpoint (it is set by the OTBus remote control)
the combination of the A+B keys remains active for the
setting of the DOMESTIC HOT WATER COMFORT
function
the domestic hot water setpoint is displayed in the INFO
menu.

8
2.5A BOILER FAULT CODES
ERROR
CODE FAULT DESCRIPTION OF ALARM TYPE
E010
ame lockout/
condensate discharge blockage
fumes discharge alarm/air intake obstructed
denitive
E011 extraneous ame transitional
E020 limit thermostat denitive
E030 fan fault denitive
E040 pressure transducer – load system denitive
E041 water transducer – load system transitional
E042 water transducer fault denitive
E060 domestic hot water probe fault transitional
E070
ow sensor fault
ow sensor overtemperature
ow/return sensor differential alarm
transitional
denitive
denitive
E077 water thermostat main zone or zone 1 (when enabled) transitional
E080
return line probe fault
return line probe overtemperature
outlet/return line probe differential alarm
transitional
denitive
denitive
E084 delivery line probe fault - zone 1 transitional
E086 delivery line probe fault - main zone transitional
E090 ue gas probe fault
ue gas probe overtemperature
transitional
denitive
E091 clean primary heat exchanger transitional
E099 reset attempts exhausted, boiler blocked denitive, not resettable
<0,6 bar Low water pressure check the HTG system
>3,0 bar High water pressure check the HTG system
COM lost communication with boiler board transitional
COMP lost communication with main zone transitional
COM1 lost communication with zone 1 transitional
FWER FW version not compatible denitive
OBCD damaged clock signalisation
OTER OTBus conguration fault
For reset faults, except for E40-E041, call engineer,
2.6A INFO MENU
Pressing key 3 on the display screen displays a list of informa-
tion regarding the operation of the boiler listed by parameter
name and value. Passing from the display of one parameter to
the next takes place by pressing respectively the keys and
. Pressing the key allows the selected parameter to be
displayed; pressing the key returns you to the main screen:
Parameter
name
Scrolling message
only if parameter P1.05 = 1
Description
I0.01 SCREED HEATING HOURS Number of hours passed with screed heater function
I0.02 CH PROBE Boiler delivery sensor value
I0.03 RETURN PROBE Boiler return sensor value
I0.04 DHW PROBE Domestic hot water probe value
I0.08 EXHAUST PROBE Flue gas probe value
I0.09 OUTDOOR TEMP PROBE Outdoor temperature sensor instantaneous value
I0.10 FILTERED OUTDOOR TEMP Outdoor temperature fi ltered value used in the thermoregulation algorithm for
calculating the heating setpoint
I0.11 DHW FLOW RATE For instantaneous boiler with fl owmeter
DHW SETPOINT Only in case of OTBus connection
I0.12 FAN SPEED Number of turns of the fan (rpm)
I0.13 MAIN ZONE OUTLET Main zone fl ow sensor value (when P4.12 = 1)
I0.14 ZONE 1 OUTLET Zone 1 fl ow sensor value (when P4.13 = 1)
I0.15 EXHAUST PROBE HOURS Number of hours the heat exchanger has been operating in “condensing mode”
I0.16 MAIN ZONE SET Main zone delivery setpoint
I0.17 ZONE 1 SET Zone 1 delivery setpoint (when P4.23 = 1)
I0.18 WATER PRESSURE System pressure
I0.30 COMFORT Domestic hot water comfort (COFF, CSTD)
I0.31 SUN ON Special functions active for high domestic hot water temperature inputs
I0.33 PCB ID Electronic board card identifi cation
I0.34 PCB FW Electronic board card fmw revision
I0.35 INTERFACE FW Interface fmw

9
3A HOW TO...
3.1A HOW TO TOP-UP THE SYSTEM
PRESSURE
The system pressure must be checked periodically to ensure
the correct operation of the boiler. Scroll the INFO menu to
10.18, the displayed pressure should be reading between 1 and
1.5 BAR when the boiler is in an off 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 “Fig. 2”).
- 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 (on the boiler) reads
between 1 and 1.5 bar.
- Remove the lling loop from the connections.
Fig. 2
control valve
ow pipe
temporary
connection
double
check- valve
control
valve
supply
pipe
3.2A HOW TO RESET THE APPLIANCE
When the fault code is displayed, the appliance will require to
be reset manually. Before resetting the boiler, check what ac-
tion is required to be taken, using the information on the fault
code table.
RESET FUNCTION
Press the RESET button. At this point, if the correct operating
conditions have been restored, the boiler will restart
automatically. There are a maximum of 3 consecutive attempts.
In case of all the attempts are exhausted the denitive fault
E099 occurs on the display. To restore from an ‘E099’ fault
code, it is necessary to momentarily switch off the electrical
supply to the appliance and then restore the electrical supply
to the appliance.
DAY
DAY
IMPORTANT
If the appliance requires to be reset frequently, it may be indica-
tive of a fault, please contact your installer or Vokèra Customer
Services for further advice.
3.3A HOW TO SHUT DOWN THE SYSTEM FOR
SHORT PERIODS
The system and boiler can be shut down,in the event of tem-
porary absences (weekends, short breaks, etc.) setting the
boiler status to OFF .
While the electrical supply and the fuel supply remain active,
the boiler is protected by the systems:
- heating anti-freeze: this function is activated if the temperature
measured by the flow sensor drops below 5°C. A heat request
is generated in this phase with the ignition of the burner at
minimum output, which is maintained until the outlet water
temperature reaches 35° C;
- domestic hot water anti-freeze: this function is activated if
the temperature measured by the domestic hot water probe
drops below 5°C. A heat request is generated in this phase
with the ignition of the burner at minimum output, which is
maintained until the outlet water temperature reaches 55° C.
b The operation of the ANTI-FREEZE function is indicated
by a scrolling message on the interface display: AF1
(DHW antifreeze in progress) - AF2 (CH antifreeze in
progress), as the case may be.
- circulator anti-locking: the circulator activates every 24
hours of stoppage for 30 seconds.
3.4A 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 off. For more detailed advice
contact your installer.
3.5A 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.
3.6A KEYBOARD LOCKOUT FUNCTION
Pressing buttons 1+3 for at least 2sec activates the key
lockout; pressing buttons 1+3 again for at least 2sec re-
activates the key. The display will show LOCK.
1
RESET
+
MENU
+
3
Button ‘2’ (reset) remains active if there is a fault to allow the
alarm to be reset.

10
4A WHAT IF...
4.1A WHAT IF I SUSPECT A GAS LEAK
If you suspect a gas leak, turn off 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 ofce.
4.2A WHAT IF I HAVE FREQUENTLY TO TOP-
UP THE SYSTEM
If the system regularly requires topping-up, it may be indicative
of a leak. Please contact your installer and ask him to inspect
the system.
4.3A WHAT IF THE APPLIANCE IS DUE ITS
ANNUAL SERVICE
Advice for tenants only
Your landlord should arrange for servicing.
Advice for homeowners
Please contact Vokèra Customer Service (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.
4.4A WHAT IF I NEED TO CALL AN ENGINEER
If you think your boiler may have developed a fault, please contact
your installer or Vokèra Customer Services (0844 3910999 (UK)
or 056 7755057 (ROI) have all your details to hand including
full address and postcode, relevant contact numbers, and your
completed appliance log book.
3.7A INTERFACE STAND BY
Usually, when there are no faults or heat requests, the display
always shows the temperature measured by the ow sensor.
If within 10 seconds there is no heat request without any key
being pressed the interface goes into stand by. The display
shows the current time, the two points separating the time
from the minutes blink with a frequency of 0.5sec ON and
0.5sec OFF, while the status icons will be active if necessary:
In the case of stand by press any button to return to normal
operating conditions.

11
35C-40C
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 PLUS is comprised of a 7-model range of high
efciency appliances, with outputs ranging from 20kW to 40kW.
These appliances – by design – incorporate electronic ignition,
circulating pump, expansion vessel, safety valve, pressure
transducer and automatic by-pass.
The VISION PLUS range is produced as room sealed, category
II2H3P appliances, suitable for internal wall mounting applica-
tions only. 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 PLUS is approved for use with C13 & C33 type
ue applications.
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.
VISION PLUS boiler complies with basic requirements of the
following Directives:
- Regulation (EU) 2016/426;
- Yield directive: Article 7(2) and Annex III of directive 92/42/
EEC;
- Electromagnetic compatibility directive 2014/30/EU;
- Low-voltage directive 2014/35/EU;
- Directive 2009/125/EC Ecodesign for energy-using
appliances;
- Regulation (EU) No. 2017/1369 Energy Labelling;
- 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 dis-
posed of as solid urban waste, but rather it should be
handed over to a differentiated waste collection centre .
1 INTRODUCTION
INSTALLATION AND SERVICING INSTRUCTIONS
Fig. 3
F O G I R
General layout
1 Gas valve
2 Drain valve
3 Pressure transducer
4 Safety valve
5 Siphon
6 De-aeration valve
7 Flow thermistor (NTC)
8 Limit thermostat
9 Main heat exchanger
10 Detection electrode
11 Burner
12 Ignition electrode
13 Ignition transformer
14 Fume analysis cap
15 Top ue outlet
16 Flue sensor
17 Expansion vessel
18 Clapet
19 Fan
20 Mixer
21 Return thermistor
22 Injector
23 Lower auto air vent
24 Pump
25 Flowmeter
26 Three port valve actuator
27 DHW exchanger
28 Pressure gauge
R Heating return connection
F Heating ow connection
G Gas connection
O Hot water outlet
I Cold water inlet

12
Fig. 4
2 DESIGN PRINCIPLES AND OPERATING SEQUENCE
Expansion
vessel
Pump
Main heat
exchanger
Bottom
AAV
DHW heat
exchanger
Diverter
valve
Drain
valve
DHW temperature
sensor
DHW
non return
valve
CH
return
CH
ow
DHW
inlet
DHW
outlet
Flow regulator
DHW ow
switch
Top AAV
High limit
thermostat
Flow temperature
sensor
Safety
valve
DHWFilter
Automatic
by-pass
Return temperature
sensor
Water transducer
2.1 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
• Stainless-steel heat exchanger
• Electronic ignition with ame supervision
• Integral high-head pump
• Fan
• Expansion vessel
• Water pressure transducer
• Flue sensor
• Safety valve
2.2 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-protection system: the frost-protection system protects
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
will function on minimum power until the temperature on main
reaches 55°C.
• anti-block function: the anti-block function enables the pump
and diverter valve actuator to be energised for short periods,
when the appliance has been inactive for more than 24-hours.
2.3 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
electronic circuitry increases the gas rate to 75% for a period
of 15 minutes.
Thereafter, the boiler’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).
When the request for heat has been satised the appliance
pump and fan may continue to operate to dissipate any residual
heat within the appliance.
2.4 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
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 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.
In the event of the appliance exceeding the desired temperature
(set point) the burner will shut down until the temperature drops.
When the request for DHW has been satised the appliance
pump and fan may continue to operate to dissipate any residual
heat within the appliance.
2.5 SAFETY DEVICES
When the appliance is in use, safe operation is ensured by:
• a water pressure transducer that monitors system water pres-
sure 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;
• a high limit thermostat that over-rides the temperature control
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.

13
2.6 TECHNICAL DATA
Central Heating VISION PLUS 35C VISION PLUS 40C
Heat input (kW) 30.00 30.00
Maximum heat output (kW) 60/80°C 29.25 29.25
Minimum heat output (kW) 60/80°C 4.65 4.65
Maximum heat output (kW) 30/50°C 32.25 32.25
Minimum heat output (kW) 30/50°C 5.08 5.08
Minimum working pressure 0.25-0.45 bar
Maximum working pressure 2.5 bar
Minimum ow rate 350 l/h
Domestic Hot Water VISION PLUS 35C VISION PLUS 40C
Heat input (kW) 34.60 40.00
Flow Rate: ΔT35°C 14.20 16.40
Maximum inlet pressure 8 bar
Minimum inlet pressure 0.15 bar
Minimum ow rate 2 l/min
Gas Pressures VISION PLUS 35C VISION PLUS 40C
Inlet pressure (G20) 20.0 mbar 20.0 mbar
Heating maximum gas rate (m3/hr) 3.17 3.17
DHW maximum gas rate (m3/hr) 3.66 4.23
Minimum gas rate (m3/hr) 0.52 0.52
Injector size (mm) 5.7 5.7
Fan speed (G20) VISION PLUS 35C VISION PLUS 40C
Slow ignition (rpm) 5.500 5.500
CH maximum number of fan rotation (rpm) 6.900 6.900
DHW maximum number of fan rotation (rpm) 7.800 9.200
Mimum number of fan rotation (rpm) 1.700 1.700
Expansion Vessel VISION PLUS 35C VISION PLUS 40C
Capacity 9 litres
Maximum system volume 74 litres
Pre-charge pressure 1 bar
Dimensions VISION PLUS 35C VISION PLUS 40C
Height (mm) 740
Width (mm) 420
Depth (mm) 350
Dry weight (kg) 37 37
Clearances VISION PLUS 35C VISION PLUS 40C
Sides 2mm*
Top 100mm** from casing or 25mm above ue elbow (whichever is applicable)**
Bottom 200mm^
Front 450mm^^
* It may be necessary to remove adjacent components if component removal/replacement is required
** Consideration should be given to providing reasonable clearance for the insertion of a FGA probe.
^ This can be reduced to 5mm if a removal panel enables the required 200mm
^^ When installed in a cupboard, this dimension can be reduced to 4mm provided that the required
450mm is available when the door is opened/removed.
Connections VISION PLUS 35C VISION PLUS 40C
Flow & return 22mm
Gas 15mm
DHW hot & cold 15mm
Safety valve 15mm
Condense 21mm
Electrical VISION PLUS 35C VISION PLUS 40C
Power consumption (Watts) DHW 92 118
Power consumption (Watts) CH 79 79
Voltage (V/Hz) 230/50
Internal fuse 3.15A T (for PCB) - 3.15A F (for connections block)
External fuse 3A
Flue Details (concentric 60-100) VISION PLUS 35C VISION PLUS 40C
Maximum horizontal ue length (60/100mm) 6.0m 6.0m
Maximum vertical ue length (60/100mm) 7.0m 7.0m
Flue Details (concentric 80-125) VISION PLUS 35C VISION PLUS 40C
Maximum horizontal ue length (80/125mm) 15.0m 15.0m
Maximum vertical ue length (80/125mm) 16.0m 16.0m
Efciency VISION PLUS 35C VISION PLUS 40C
SEDBUK 2005 (%) 90.00 90.03
Emissions VISION PLUS 35C VISION PLUS 40C
CO2 @ maximum output (%) 9.1 9.1
CO2 @ minimum output (%) 9.0 9.0
CO @ maximum output (ppm) 150 150
CO @ minimum output (ppm) 10 10
NOx rating class 6 class 6

14
NOTE (if the outdoor temperature sensor or the control panel, or even both devices, are present in the boiler)
With reference to the Delegated Regulation (EU) No. 811/2013, the information in the table can be used for completing the product
data sheet and the labelling for room heating appliances, for mixed heating appliances, for all those appliances for enclosed space
heating, for temperature control devices and solar devices:
ADDED DEVICES CLASS BONUS
OUTDOOR TEMPERATURE SENSOR II 2%
CONTROL PANEL* V 3%
OUTDOOR TEMPERATURE SENSOR + CONTROL PANEL* VI 4%
(*) Set as ambient regulator
VISION PLUS 35C
Seasonal space heating energy efciency class AWater heating energy efciency class A
Parameter Symbol Value Unit Parameter Symbol Value Unit
Rated heat output Prated 29 kW Seasonal space heating
energy efciency ηs 92 %
For boiler space heaters and boiler combination heaters: useful heat output For boiler space heaters and boiler combination heaters: useful efciency
At rated heat output and high-
temperature regime (*) P4 29,3 kW At rated heat output and high- temperature regime (*) η4 87,6 %
At 30% of rated heat output and
low-temperature regime (**) P1 9,7 kW At 30% of rated heat output and low-temperature regime (**) η1 96,5 %
Auxiliary electricity consumption Other parameters
At full load elmax 41,0 W Stand-by heat loss Pstby 38,0 W
At part load elmin 14,0 W Pilot ame energy consumption Pign - W
In Stand-by mode PSB 3,0 W Annual energy consumption QHE 65 GJ
Sound power level, indoors LWA 52 dB
Emissions of nitrogen oxides NOx 43 mg/kWh
For combination heaters:
Declared load prole XXL Water heating energy efciency ηwh 88 %
Daily electricity consumption Qelec 0,158 kWh Daily fuel consumption Qfuel 27,482 kWh
Annual electricity consumption AEC 35 kWh Annual fuel consumption AFC 22 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 PLUS 40C
Seasonal space heating energy efciency class AWater heating energy efciency class A
Parameter Symbol Value Unit Parameter Symbol Value Unit
Rated heat output Prated 29 kW Seasonal space heating
energy efciency ηs 92 %
For boiler space heaters and boiler combination heaters: useful heat output For boiler space heaters and boiler combination heaters: useful efciency
At rated heat output and high-
temperature regime (*) P4 29,3 kW At rated heat output and high- temperature regime (*) η4 87,6 %
At 30% of rated heat output and
low-temperature regime (**) P1 9,7 kW At 30% of rated heat output and low-temperature regime (**) η1 96,5 %
Auxiliary electricity consumption Other parameters
At full load elmax 41,0 W Stand-by heat loss Pstby 38,0 W
At part load elmin 14,0 W Pilot ame energy consumption Pign - W
In Stand-by mode PSB 3,0 W Annual energy consumption QHE 65 GJ
Sound power level, indoors LWA 52 dB
Emissions of nitrogen oxides NOx 43 mg/kWh
For combination heaters:
Declared load prole XXL Water heating energy efciency ηwh 86 %
Daily electricity consumption Qelec 0,167 kWh Daily fuel consumption Qfuel 28,125 kWh
Annual electricity consumption AEC 37 kWh Annual fuel consumption AFC 22 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).

15
Fig. 5
2.7 PUMP DUTY
Fig. 4 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.
Flow rate (l/h)
Residual head (mbar)
2.8 HOW TO FREE THE PUMP
To “release” the seized rotator shaft:
- set boiler status to OFF by pressing button 1
- remove the casing as detailed in paragraph “4.7”
- remove the circulator cap
- with a slotted screwdriver, rotate the shaft being careful not
to strain the seat (Fig. 6)
- to extract the connector holder, lever with a screwdriver as
shown in Fig. 7
- ret the cap and press key 1 to select the type of operation
desired.
Carry out the operation with extreme caution so as not to da-
mage the components themselves.
1
Fig. 6
Fig. 7
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 height)
Fig. 8
0
50
100
150
200
250
300
350
400
450
500
550
600
0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300

16
3 GENERAL REQUIREMENTS (UK)
This appliance must be installed by a competent person in ac-
cordance with the Gas Safety (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.
ATTENTION
The use of PPE (Personal Protective Equipment) such as but
not limited to gloves, mask, safety glasses, etc. is strongly
recommended whenever carrying out the installation, repair,
or maintenance of this appliance – please pay particular at-
tention to:
• Sharp edges that may be encountered when:- handling or
lifting the appliance, removing parts, etc. during installation
and maintenance
• Airborne particles that may be released and/or disturbed
when cleaning or removing components during maintenan-
ce
• Water treatment chemicals that could have been added to
the system water may spill from the appliance and or com-
ponents during maintenance
Please refer to an appropriate Health and Safety document
such as HSE L23 (UK) or S.I. 299 (Ireland), for more detailed
advice on safe working practices and procedures.
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.
NOTE
It is recognised that ‘pressure loss’ through the gas cock and
gas valve may result in a pressure drop of approximately 2mbar
between the gas meter and gas valve inlet test point; this will
not impair the performance of the appliance, provided that a
dynamic pressure of 18mbar is available at the appliance inlet.
3.4 FLUE SYSTEM
The terminal should be located where the dispersal of combustion
products is not impeded and with due regard for the damage
and discoloration that may occur to building products located
nearby. The terminal must not be located in a place where it is
likely to cause a nuisance (see “Fig. 8”). 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 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, 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.
This appliance is a room-sealed, fan-ued boiler, consequently
it does not require a permanent air vent for combustion air 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
It is recommended that copper tubing to BS 2871 Part 1 is 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.
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.
3.2 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.
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
appliance will be in an unusual location special procedures may
be necessary, BS 6798 gives detailed guidance on this aspect.
Acompartment used to enclose the appliance must be designed
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.
Pipe work from the meter to the appliance must be of 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 BS6891.
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

17
3E GENERAL REQUIREMENTS (EIRE)
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 9 litres of expansion from within
the system, generally this is sufcient, however if the system
has an unusually high water content, it may be necessary to
provide additional expansion capacity (see 7.21).
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, is required
(see “Fig. 17”). This method of lling should comply with the cur-
rent Water Supply (Water Fittings) Regulations 1999 and Water
Bylaws 2000 (Scotland). If an alternative location is preferred,
it should be connected as detailed in Fig. 9.
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
least 1 metre above the highest point in the system and at least
5 metres above the boiler (see “Fig. 10”).
The cold feed from the make-up vessel or tank must be tted
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.
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
The appliance is supplied for operation on 230V @ 50Hz electri-
cal supply; it must be protected with a 3-amp fuse. The method
of connection to the mains electricity supply must allow for
complete isolation from the supply. The preferred method is by
using a double-pole switch fused spur with a contact separation
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.
NOTE
Vokera Ltd. cannot guarantee the performance or reliability of
the appliance if/when it is supplied via an invertor or generator;
in particular those that incorporate a ‘oating’ earth or ‘modied’
sine wave.
Warning!
This appliance must be earthed.
3.8 MOUNTING ON A COMBUSTIBLE SURFA CE
The appliance can be mounted on a wall of combustible ma-
terial without any requirement to t any additional protective
(re-resistant) material.
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 WATER TREATMENT
Vokèra recommend that an inhibitor - suitable for use with
stainless-steel heat exchangers - is used to protect the boiler
and system from the effects of corrosion and/or electrolytic ac-
tion. 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
and the Domestic Water Treatment Association’s (DWTA)
code of practice. Vokera recommend that water treatment be
carried out in accordance with the Benchmark Guidance on
water treatment in central heating systems. If water treatment
products are to be used, then they must be entirely suitable for
use with an Stainless-steel heat exchanger. Any water treat-
ment product, must be administered in strict accordance with
the manufacturer’s instructions.
If the appliance is to be installed to an existing system; water
treatment and ushing of the complete heating system should
be carried out in accordance with BS 7593 and the Benchmark
Guidance on water treatment in central heating systems.
3.11 SHOWERS
If the appliance is intended for use with a shower, the shower
must be thermostatically controlled and be suitable for use with
a combination boiler.
control valve
ow pipe
temporary
connection
double
check- valve
control
valve
supply
pipe
Make-up vessel
or tank
Automatic
air-vent
Non-return
valve
Stopcock
5.0 metres minimum
Heating
return
Fig. 9
Fig. 10
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).
3.1E 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.
ATTENTION
The use of PPE (Personal Protective Equipment) such as but
not limited to gloves, mask, safety glasses, etc. is strongly
recommended whenever carrying out the installation, repair,
or maintenance of this appliance – please pay particular at-
tention to:
• Sharp edges that may be encountered when:- handling or
lifting the appliance, removing parts, etc. during installation
and maintenance
• Airborne particles that may be released and/or disturbed when
cleaning or removing components during maintenance
• Water treatment chemicals that could have been added to
the system water may spill from the appliance and or com-
ponents during maintenance
Please refer to an appropriate Health and Safety document
such as HSE L23 (UK) or S.I. 299 (Ireland), for more detailed
advice on safe working practices and procedures.
3.2E 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 National Rules for Electrical Installations, 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. The location chosen for the appli-
ance must permit the provision 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.

18
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-
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.
3.3E 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.
Pipe work from the meter to the appliance must be of 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.
NOTE
It is recognised that ‘pressure loss’ through the gas cock and
gas valve may result in a pressure drop of approximately 2mbar
between the gas meter and gas valve inlet test point; this will
not impair the performance of the appliance, provided that a
dynamic pressure of 18mbar is available at the appliance inlet.
3.4E FLUE SYSTEM
The terminal should be located where the dispersal of combustion
products is not impeded and with due regard for the damage
and discoloration that may occur to building products 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 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 at roofs)
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.
3.5E AIR SUPPLY
The following notes are intended for general guidance only.
This appliance is a room-sealed, fan-ued boiler, consequently it
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.
3.6E WATER CIRCULATION
Specic recommendations are given in I.S. 813. The following
notes are for general guidance only.
3.6.1E 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.
3.6.2E 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’.
3.6.3E DRAIN COCKS
These must be located in accessible positions to facilitate
draining of the appliance and all water pipes connected to the
appliance.
3.6.4E 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.
3.6.5E EXPANSION VESSEL
The appliance has an integral expansion vessel to accommo-
date the increased volume of water when the system is heated.
Refer to the specication table for more detailed information.
3.6.6E 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 “Fig. 17”). This method of lling complies with
the current Water Supply (Water Fittings) Regulations 1999
and Water Bylaws 2000 (Scotland).
3.6.7E 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 “Fig. 10”). The cold feed from
the make-up vessel or tank must be tted 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.
3.6.8E 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.
3.7E 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 complete isolation from the supply. The preferred 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.
NOTE
Vokera Ltd. cannot guarantee the performance or reliability of
the appliance if/when it is supplied via an invertor or generator;
in particular those that incorporate a ‘oating’ earth or ‘modied’
sine wave.
3.8E MOUNTING ON A COMBUSTIBLE
SURFACE
The appliance can be mounted on a wall of combustible ma-
terial without any requirement to t any additional protective
(re-resistant) material.
3.9E 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.
3.10E WATER TREATMENT
Vokèra recommend that an inhibitor - suitable for use with
Stainless-steel heat exchangers - is used to protect the boiler
and system from the effects of corrosion and/or electrolytic ac-
tion. 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
and the Domestic Water Treatment Association’s (DWTA)
code of practice. Vokera recommend that water treatment be
carried out in accordance with the Benchmark Guidance on
water treatment in central heating systems. If water treatment
products are to be used, then they must be entirely suitable for
use with an Stainless-steel heat exchanger. Any water treat-
ment product, must be administered in strict accordance with
the manufacturer’s instructions.
If the appliance is to be installed to an existing system; water
treatment and ushing of the complete heating system should
be carried out in accordance with BS 7593 and the Benchmark
Guidance on water treatment in central heating systems.
3.11E SHOWERS
If the appliance is intended for use with a shower, the shower
must be thermostatically controlled and be suitable for use with
a combination boiler.
3.12E 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.

19
4 INSTALLATION
NOTE
Please refer to 3 - 3E and use the appropriate PPE when
carrying out any of the actions or procedures contained within
this section.
4.1 PREPARATION FOR MOUNTING THE
APPLIANCE
The appliance should be mounted on a smooth, vertical sur-
face, 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 – using
the template supplied – carefully mark the position of the wall
mounting bracket (see Fig. 11) and ue-hole (if applicable).
4.2
Fig. 11
A
FITTING THE FLUE
This appliance incorporates a ‘click-t’ ue connection at the
top of the appliance.
4.2.1 CONCENTRIC HORIZONTAL FLUE
These instructions relate specically to the installation of this
appliance with the Vokera 60/100mm ‘X-type’ (click-t) ue
terminals accessories. For specic instructions on installing this
appliance with an alternative Vokera ue system, e.g. 80/125mm;
please refer to the instructions supplied with the specic ue
system, or download the instructions from the Vokera website.
The appliance ue outlet elbow can be rotated through 360º
on its vertical axis. In addition the ue may be extended from
the outlet elbow in the horizontal plane. A reduction must also
be made to the maximum length (see table below) when ad-
ditional bends are used.
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
Part No. Description Length
20122759 Standard horizontal ue Kit 900mm
20122761 Telescopic ue kit 700mm
20132059 90-degree bend N/A
20132058 45-degree bend (2) N/A
20132060 500mm extension 500mm
20132061 1000mm extension 1000mm
20132062 2000mm extension 2000mm
20131979 telescopic extension 372/519mm
522 plume management kit 1370mm
20135587 100mm ue brackets (5) N/A
Fig. 11: Using the template (A) provided with the kit, mark and
drill a 125mm hole (B) for the passage of the ue pipe. The hole
should be drilled to ensure any condense uid that forms, is
allowed to drain 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, mount the appliance onto the bracket.
NOTE PRE-FIXING JIG
A ‘Pre-xing Jig’ is available as an accessory (code 20177531),
should it be necessary to pre-fabricate the appliance pipework,
i.e. rst-x, prior to installing the appliance.
4.2.2 FITTING THE TELESCOPIC HORIZONTAL FLUE
KIT
In some instances it may necessary to cut the inner 60mm pipe
of the ue bend at the point indicated (Fig. 13- pos. A) to allow
for easier insertion to the boiler ue spigot.
4.2.3 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
Fig. 13). Measure dimension Y from the terminal end of the
concentric ue pipe and cut off the excess ensuring any burrs are
removed. Pass the concentric ue pipe through the previously
drilled hole. Fit the ue bend to the boiler ue outlet and insert
the concentric ue pipe into the ue bend ensuring the correct
seal is made.
NOTE (Fig. 14): The appliance incorporates a ‘click-t’ ue
connection. Ensure that both screws ‘C’ on the ‘click-t’ have
been slackened off. 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 ue bend connector). Both screws (C) should
now be tightened.
NOTE
Fit the internal (white) trim to the flue assembly prior to
connecting the ue pipe to the bend.
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.
A
A
C
C
B
Fig. 12

20
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. Once the bracket has been secured to the wall, 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
- all seals are properly located before assembling or connecting
the ue system.
IMPORTANT: The VX ue terminal is 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 vertical
ue connector (supplied with the VX terminal).
NOTE (Fig. 14): The appliance incorporates a ‘click-t’ ue
connection. Ensure that both screws ‘C’ on the ‘click-t’ have
been slackened off. 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). 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
Reduction for bends
Bend Reduction in maximum ue length for each bend
45º bend 1.0 metre
90º bend 1.0 metre
Vertical Flue Terminals & Accessories
Code Description Length
20122763 Vertical Flue Kit 1000mm
20132059 90-degree bend N/A
20132058 45-degree bend (2) N/A
20132060 500mm extension 500mm
20132061 1000mm extension 1000mm
20132062 2000mm extension 2000mm
20131979 telescopic extension 372/519mm
20135587 100mm ue brackets (5) N/A
20132050 pitched roof ashing N/A
20135582 at roof ashing N/A
A
Fig. 13
Fig. 14
4.2.4 EXTENDING THE FLUE
Connect the bend – supplied with the terminal kit – to the top
of the boiler using clamp (supplied). 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 (Fig. 15). 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
ensure that the excess is cut from the plain end of the exten-
sion (Fig. 15). 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.
4.5.2 CONCENTRIC VERTICAL FLUE
Using Fig. 17 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
in position - is covered and protected from the possibility of any
dust or debris falling or entering the appliance via the ue outlet.
Fig. 15
Fig. 16