Grant Internal Vecta User manual

UK | DOC 0048 | Rev 1.1 | July 2020
Grant Internal Vecta
4-16kW Condensing Wood Pellet Boiler and Side
Pellet Store
User Instructions

GRANT ENGINEERING (UK) LIMITED
Hopton House, Hopton Industrial Estate, Devizes, Wiltshire, SN10 2EU
Tel: [phone] Fax: [phone]
Email: [email protected] www.grantuk.com
This manual is accurate at the date of printing but will be superseded and should be disregarded if specifications and/or appearances
are changed in the interests of continued product improvement. However, no responsibility of any kind for any injury, death, loss, damage
or delay however caused resulting from the use of this manual can be accepted by Grant Engineering (UK) Limited, the author or others
involved in its publication.
All goodssold are subject to our official Conditions of Sale, a copy of which may be obtained on application.
© Grant Engineering (UK) Limited 2017. No part of this manual may be reproduced by any means without prior written consent.
Important Note for Installers
This guide is intended to assist and instruct the user in the operation
of the Grant Vecta wood pellet boiler.
A separate manual is available to the installer for the installation,
servicing and commissioning of the boiler.
Special Text Formats
The following special text formats are used in this manual for the
purposes listed below:
Warning of possible human injury as a consequence of not
following the instructions in the warning.
!WARNING
Caution concerning likely damage to equipment or tools as a
consequence of not following the instructions in the caution.
!CAUTION
Used for emphasis or information not directly concerned with
the surrounding tex t but of importance to the reader.
NOTE
!

1 About your Boiler 4
2 About your Fuel 7
3 Boiler Control Panel 8
4 Boiler Overheat Thermostat 11
5 Electrical Isolator Switch 11
6 Safety Charge Pipe Thermostat 11
7 The Grant Logo Indicator 12
8 Lighting the Boiler 12
9 If your Boiler fails to Start 13
10 Cleaning and Servicing your Boiler 15
11 Emptying the Ash Pan 15
12 Ventilation 17
13 Electricity Supply 17
14 Sealed Heating System 18
15 Frost Protection 18
16 Service Log 19
This appliance can be used by children aged from 8 years and above and persons with
reduced physical, sensory or mental capabilities or lack of experience and knowledge
if they have been given supervision or instruction concerning use of the appliance in a
safe way and understand the hazards involved. Children shall not play with the appliance.
Cleaning and user maintenance shall not be made by children without supervision.
Contents Page 3
Contents

User InstructionsPage 4
General
Your Grant Vecta wood pellet boiler should only be installed,
commissioned and serviced by an Installer who has undergone
specific product training by Grant Engineering (UK) Limited.
1.1 Condensing Boiler Operation
During the combustion process, hydrogen and oxygen combine to
produce heat and water vapour. The water vapour produced is in the
form of superheated steam that contains heat that is locked up in the
flue gases. A conventional boiler cannot recover any of this heat and
this energy is lost to the atmosphere through the flue.
The Grant Vecta condensing wood pellet boiler contains an extra
(secondary) heat exchanger which is designed to recover much of the
heat normally lost by a conventional boiler through the flue system.
It does this by cooling the flue gases and extracting more heat from
them, pre-heating the cooler water returning to the boiler from your
heating system. Even when not operating in a condensing mode, this
additional heat exchanger ensures that your Grant Vecta boiler will still
operate at an extremely high efficiency.
1.2 Access
Your Internal Vecta wood pellet boiler is fitted with the following:
• A hinged front door with a flush-fitting lockable door catch. This
door allows access to the boiler for routine cleaning (emptying
the ash pan).
To open the door, unlock the door catch (located on the left side
of the door) with the key provided.
Pull out the door catch handle and rotate the handle
anticlockwise to unlatch and open the door. Refer to Figure 2.
• A hinged hopper lid on the top of the boiler casing. This allows
access to the boiler pellet hopper to top up the pellet level when
required.
1 About your Boiler
1.3 Pellet Hopper
The pellet hopper is an integral part of the boiler and is accessed for
filling by lifting the hinged hopper lid on the top. Refer to Figure 1. The
hopper lid must be closed for the boiler to operate.
Figure 1: Front/left side view of the boiler - lid open
The maximum capacity of the pellet hopper is 60kg. The pellet hopper
is fitted with a contents switch. This automatically detects when the
level of pellets in the hopper falls to a pre-set minimum value.
At this point the LCD screen will flash and display the ‘Fuel Low
Warning’ message (refer to Section 3). The Grant logo (on the front
of the boiler), and the optional Remote Grant logo Indicator (if fitted),
will also flash slowly to indicate the pellet level has fallen to the pre-set
minimum.
As soon as this happens the hopper should be topped up with more
pellets. This will automatically cancel the flashing Grant logo (and
remote Grant logo indicator, if fitted) and the flashing ‘Fuel Low
Warning’ message on the control panel LCD screen.
If the pellet hopper is not topped up at this point, the boiler
will continue to operate for a short period before the burner is
automatically stopped. The Grant logo (and remote Grant logo
indicator, if fitted) will continue to flash slowly, with the flashing ‘Low
Fuel Warning’ message on the control panel LCD screen, to indicate
the lack of pellets in the boiler.
If this happens, simply top up the hopper with more pellets. A
minimum of 20kg of pellets will operate the contents switch and

User Instructions Page 5
automatically re-start the burner (as long as there is a demand for the
boiler to run).
Figure 2: Front/left side view of boiler - door open
1.4 Topping up the Pellet Hopper
When required (see Section 1.3 above), the boiler pellet hopper can
be easily topped as follows:
• Pull down the hinged cover at the top of the front door of the
boiler to access the control panel.
• Set the ON/STANDBY switch on the control panel to STANDBY. If
the boiler is operating at the time, wait for the boiler to complete
the burner shut down sequence.
• Then open the hinged hopper lid on the top of the boiler casing.
Lift the lid until it is fully open.
• Tip pellets from a bag into the opening at the top right rear of
the boiler. A minimum of 20kg of pellets (i.e. two 10kg bags)
is sufficient to operate the contents switch. However, it is
recommended to completely fill the pellet hopper up to the grille
in the hopper opening.
• When the topping up is completed, close the hinged hopper lid.
• Set the ON/STANDBY switch on the control panel to ON. The
boiler will then re-start (as long as there is a demand to do so
from the heating system controls).
BEFORE opening the lid to top up the pellet hopper, always set
the ON/STANDBY switch to STANDBY, and wait for the boiler to
complete the shut down sequence.
The LCD screen will indicate ‘Standby’ when the shutdown
sequence is completed. Reset the ON/STANDBY switch to ON
after top up is completed.
NOTE
!
After topping up the hopper, always ensure that the pellet
hopper lid is closed as the safety cut-out switch will prevent
the boiler from operating if the lid is open. The hopper should
only be filled to the point where it is still possible to close the
hopper lid. When filling the hopper, ensure no foreign debris
enters the hopper.
!CAUTION
1.5 Hopper Lid Cut-out Switch
The hinged hopper lid is fitted with a safety cut-out switch.
The lid MUST BE CLOSED for the boiler to operate. If the lid is opened
for longer than FIVE seconds, whilst the boiler is operating, the burner
will be automatically shut down.
The control panel LCD screen will flash and indicate a ‘Hopper Lid
Open’ fault. Closing the hopper lid automatically resets the cut-out
switch but the control panel LCD screen will continue to flash, now
indicating a ‘Safety Flap Closed’ fault. After 30 seconds this fault
message will automatically disappear, the burner will complete the
shut down sequence and then restart.
1.6 Side Pellet Store
If fitted with your Grant Vecta boiler, the optional side pellet store is
designed to provide an increased storage capacity, allowing the boiler
to run for longer periods before topping-up of the boiler pellet hopper
and side pellet store is required.
The capacity of the side pellet store is 140kg. With the 60kg capacity
of the boiler pellet hopper this gives a total pellet storage capacity of
200kg.
This side pellet store is located against the right hand side of the
boiler. Refer to Figure 3.
Figure 3: Boiler with optional side pellet store fitted
The boiler pellet hopper is fitted with a contents switch. Refer to
Section 1.2. When the level of the pellet in the hopper falls to a pre-
set minimum value the control panel LCD screen will show ‘Fuel
Low Warning’ and the Grant logo (on the front of the boiler), and the
optional Remote Grant logo Indicator (if fitted), will also flash (slowly)
to indicate that the pellet level in the boiler hopper has fallen to the
pre-set minimum.
Pellets will be automatically transferred from the side pellet store to
the boiler pellet hopper. This will continue until the contents switch
in the boiler pellet hopper is satisfied, at which point the side pellet
store auger will stop. Both the ‘Fuel Low Warning’ on the control panel

User InstructionsPage 6
LCD screen and the slow flashing Grant logo (and remote Grant logo
indicator, if fitted) will be automatically cancelled.
The boiler pellet hopper will not be completely filled by the side
pellet store. The auger will only transfer pellets to the boiler
pellet hopper until the contents switch is satisfied.
NOTE
!
The side pellet store is also fitted with a contents switch. The side
pellet store auger will only operate when this contents switch indicates
there are sufficient pellets in the side pellet store. If this level drops
below the minimum to activate the contents switch, the auger will no
longer operate to transfer pellets to the boiler pellet hopper.
In this instance, when the boiler pellet hopper contents switch detects
a low fuel level, no pellets will be transferred to the boiler pellet hopper.
The control panel LCD screen will show ‘Fuel Low Warning’ and the
Grant logo (on the front of the boiler) and the optional Remote Grant
logo Indicator (if fitted), will also flash (slowly) to indicate that the pellet
level in the boiler hopper has fallen to the pre-set minimum.
If the boiler pellet hopper is not topped up at this point, the boiler
will continue to operate for a short period before the burner is
automatically stopped.
Topping up the boiler pellet hopper with at least 20kg of pellets will
operate the contents switch and automatically re-start the burner (as
long as there is a demand present for the boiler to run). Both the ‘Fuel
Low Warning’ on the boiler control panel LCD screen and the slow
flashing Grant logo will be automatically cancelled.
In order to maximise the combined pellet storage capacity of
the boiler and side pellet store, it is recommended that both the
boiler pellet hopper and the side pellet store are filled to the
top when topping-up with pellets.
NOTE
!
The hinged lid on the side pellet store MUST be closed first to allow
the boiler hinged lid to close. The boiler (and side store) hinged lid
must be closed to activate the lid safety cut-out switch or the burner
will not operate. Refer to Section 1.3.
The hinged lids on BOTH the boiler and the optional side pellet
store (if fitted) MUST BE CLOSED for the boiler to operate. If
either the boiler hopper lid or side pellet store lid is opened for
longer than FIVE seconds, whilst the boiler is operating, the
burner will be automatically shut down.
NOTE
!
1.7 Boiler Operation
The burner output is determined by the delivery rate of the pellets via
the pellet feed auger (inside the pellet hopper). This is automatically
controlled by the boiler control system. During commissioning the
boiler control parameters will have been checked and adjusted as
necessary by your Installer.
Do not adjust or modify the appliance in any way as to do so
could cause malfunction of the appliance, injury to persons or
death or result in a potential fire hazard. Only an Installer, who
has completed the Grant UK training course, should carry out
any work on the appliance.
!WARNING
Once commissioned by a Grant trained Installer, your Grant Vecta
boiler will operate automatically to provide heating and domestic hot
water (if you have a hot water cylinder fitted), as long as:
• There are sufficient pellets of the correct type in the pellet
hopper (refer to Section 2)
• The heating system controls are set to ON and ‘calling’, i.e. the
programmer and room thermostat are on.
• The boiler ON/STANDBY switch on the control panel is set to ON
(refer to Section 3)
If your appliance is controlled by a remote programmer and/or a room
thermostat, it will provide heating and (when fitted) hot water during
the ON periods as set on the programmer, when either the room
thermostat and/or the hot water cylinder thermostat are ‘calling’.
Certain external surfaces of the boiler will be hot to touch when
in operation, due care is needed.
!WARNING
1.8 Cleaning
The burner, located within the boiler combustion chamber,
incorporates a brazier where the combustion of the wood pellets takes
place. This brazier is fitted with a self-cleaning system to prevent a
build-up of ash and clinker. This operates automatically after a pre-set
period has elapsed.
The heat exchanger of the Grant Vecta boiler has a self-cleaning
system to keep the heat exchanger tubes clear of ash build-up.
The Grant Vecta is a condensing boiler and, as such, has a second
(condensing) heat exchanger. Refer to ‘Condensing Boiler Operation’
(Section 1.1) for more details on how this works. This second heat
exchanger is fitted with a ‘wash down’ system to keep the tubes clear
of any ash build-up.
As with the brazier cleaning system, the heat exchanger cleaning
systems are operated automatically after a pre-set period has elapsed
and also whenever power is reconnected to the boiler.
Even with the automatic cleaning systems, it is vitally important
that the boiler ash pan is regularly emptied and the boiler
regularly serviced. Refer to Section 11 of these instructions for
further information on cleaning and servicing your boiler.
!CAUTION

User Instructions Page 7
Wood Pellets
Your Grant Vecta boiler is designed to run on 6mm diameter EN Plus Grade A1 wood pellets (conforming to EN14961-2).
ONLY EN Plus Grade A1 (EN14961-2) wood pellets MUST be used with your Grant Vecta boiler. These pellets must be bark and
sand free.
!CAUTION
Failure to use pellets that meet the conditions above will invalidate the product guarantee. If you are in any doubt over which pellets are suitable
please contact Grant UK for assistance.
2 About your Fuel
Correct grade of pellets. Meets EN Plus Grade A1
Correct diameter and length with no dust and minimum bark content.
Poor quality pellets. Not pressed correctly causing them to easily disintegrate.
DO NOT USE!
Auger will be unable to consistently deliver these pellets from the hopper to the burner,
resulting in pellet lighting problems.
Pellets too dark in colour. High bark content.
DO NOT USE!
These will cause excessive sand in ash resulting in clinker blocking air holes, poor
combustion and jamming of the brazier cleaning system.
Pellets too short in length.
DO NOT USE!
Auger will not be able deliver these pellets at the correct rate to the burner, affecting the input
(and output) of the boiler and the combustion.
Pellets with high dust content.
DO NOT USE!
Auger will not be able deliver these pellets from the hopper to the burner, resulting in pellet
lighting problems.

User InstructionsPage 8
The boiler control panel is located in the top front panel of the boiler.
To access the control panel pull down the cover. Refer to Figure 4.
3 Boiler Control Panel
The boiler control panel has the following (refer to Figure 5):
• ‘ON/STANDBY’ switch
• LCD screen
• Boiler control setting buttons
The control panel is used by the Installer or Grant Service Engineer
to check and adjust the boiler settings during commissioning or
servicing.
T: 69.5°C
SP: 75.0°C
Modulation Level
Heating Demand
STANDBY
ON
V
V
V
V
V
V
2
1
3
5
4
6
i
Figure 5: Boiler Control Panel
3.1 ON/STANDBY Switch
The function of this switch is to switch the boiler ON or OFF when
required. This switch interrupts the switched live supply to the burner
from the heating system controls, i.e. the remote programmer and
room thermostat. This switch MUST be left in the ON position during
normal operation of the boiler.
This switch does NOT isolate the electrical supply to the burner.
!WARNING
3.2 Control Panel LCD Screen
This displays information about the boiler operating condition and also
allows the installer to check and adjust the boiler control settings.
3.2.1 ‘Home Screen’ Display
This is the normal display on the LCD screen and indicates the
following information about the boiler:
• The current boiler temperature (top left corner)
• The boiler ‘Setpoint’ temperature (top right corner)
• Heating demand present or not (upper centre)
• Functions in operation (mid centre) – Lambda sensor, Fan,
Ignition element, Auger, Flame on.
• Operating sequence stage (bottom left)
• Modulation indicator (bottom right) – e.g. 4 segments
=100%, 3 segments = 75%, etc.
T: 69.5°C
SP: 75.0°C
Modulation Level
Heating Demand
Figure 6: Control panel LCD screen
Figure 4: Opening control panel cover
Boiler water
temperature
Set point
temperature

User Instructions Page 9
3.2.2 Setpoint Temperature
The ‘Setpoint’ temperature (SP) is constantly displayed in the top right
corner of the control panel LCD screen. Refer to Figure 6.
The ‘Setpoint’ temperature is set by the Installer during
commissioning, using buttons 5 and 6, within the range 55°C to 75°C.
Refer to Figure 6. Typically it will be set to 70-75°C. This is the ‘target’
temperature setting about which the modulation of the boiler output
will operate.
• At 5°C or more below the set point temperature: the boiler is in
100% power mode.
• At 5°C above the set point temperature: the boiler has reached
minimum output.
The ‘Setpoint’ temperature is NOT the temperature at which the
burner stops. The maximum boiler temperature at which the burner
will cut out is factory set in the boiler control settings. This can, if
required, be adjusted by the Installer or Grant Service Engineer. Refer
to Figure 6.
To adjust the boiler ‘Setpoint’ temperature (when in ‘Home
Screen’) – refer to Figure 7
• Press button 4
• Adjust ‘Setpoint’ temperature by pressing button 5 (to decrease)
or button 6 (to increase)
• Press button 4 to confirm the new setting and return to the ‘Home
Screen’ display
The boiler ‘Setpoint’ temperature can be set between 55°C and 75°C.
The factory default setting is 75°C.
T: 69.5°C
SP: 75.0°C
Modulation Level
Heating Demand
STANDBY
ON
V
V
V
V
V
V
2
1
3
5
4
6
i
Figure 7: Boiler control panel - ‘Setpoint’ temperature adjustment
3.2.3 Boiler Water Temperature
The boiler water temperature (T) is constantly displayed in the top left
corner of the control panel LCD screen. Refer to Figure 6. This is the
actual temperature of the water in the boiler at that point in time.
When the burner cuts out the temperature will continue to rise
as the heat from the flame is transferred to the system water in
the boiler.
NOTE
!
3.2.4 Boiler Operating Modes
At any point during the start-up, running and shutting down of the
boiler, the boiler operating mode is shown across the bottom of the
control panel LCD screen. Refer to Figure 8.
T: 69.5°C
SP: 75.0°C
Modulation Level
Heating Demand
STANDBY
ON
V
V
V
V
V
V
2
1
3
5
4
6
i
Figure 8: Boiler control panel LCD screen - boiler operating mode
indication
This can be one of several modes, depending on the operation of the
boiler at the time it is viewed, as follows:
• Standby – Boiler is in standby mode, awaiting a signal from
the heating system controls and/or for the burner ON/STANDBY
switch to be set to ON to start the boiler.
• Wait Pre Load Brazier – Period for initial loading of pellets into
the burner brazier to enable the burner to be lit.
• Lighting – Period of time taken for the pellets to light
• Flame Stabilisation – Period of time allowed for the flame to
stabilise.
• Lighting Feed Reduced – Period of time when small amounts
of pellets are added to build up the flame in the brazier.
• Modulation Level – Burner is now firing. The output modulation
is shown on the modulation indicator. Refer to Figure 9.
• If four segments are showing: output =100%
• If three segments are showing: output = 75%
• If two segments are showing: output = 50%
• If one segment is showing: output = 25%.
• Turning Off Brazier – Burn down period to remove any pellets
remaining in the brazier.
• Wait Post Purge – Period of time during which the fan continues
to run to purge combustion gases from the boiler.
3.2.5 Operating Symbols
There are five symbols that can be displayed on the control panel
LCD screen. These indicate what within the boiler is active at any point
when the boiler is running.
T: 69.5°C
SP: 75.0°C
Modulation Level
Heating Demand
Figure 9: Burner control panel LCD screen - operating symbols and
modulation level
‘Setpoint’ temperature
(set by Installer)
Press to increase
‘Setpoint’ temperature
Press to decrease
‘Setpoint’
temperature
Press first to access ‘Setpoint’ adjustment
Press after adjustment to confirm setting and
return to ‘Home Screen’
Boiler operation mode
Operating symbols Modulation level

User InstructionsPage 10
The function indicated by each of these ‘Operating symbols’ is as
follows (left to right):
• Lambda sensor operating
• Fan running
• Ignition element on
• Pellet auger running
• Burner alight
Not all operating symbols will be displayed at the same time.
Only those indicating a function in operation at that moment will
be shown on the control panel LCD screen.
NOTE
!
3.2.6 Service Indicator
The boiler control panel will indicate when a service is required by
showing the word ‘Service’ on the control panel LCD screen.
This will occur after a pre-set period of pellet auger running time has
elapsed. When you see the ‘Service’ message on the burner control
panel LCD screen you should contact you Grant Approved Installer
and arrange for your boiler to be serviced.
3.2.7 Low Fuel Indicator
The boiler control panel will indicate when the minimum level of
pellets in the pellet hopper has been reached (as detected by the
pellet hopper contents switch). The LCD screen will flash and display
the ‘Fuel Low Warning’ message. The Grant logo (on the front of the
boiler) and the optional Remote Grant logo Indicator (if fitted), will
also flash slowly to indicate the pellet level has fallen to the pre-set
minimum.
When you see the Grant logo flashing slowly, and the boiler control
panel LCD screen flashing with the ‘Fuel Low Warning’ message
displayed, the hopper (and optional side pellet store – if fitted) should
be topped up with more pellets. If the hopper is not topped up at this
point, the boiler will stop operating after a short time. Refer to Section
1.
3.2.8 Fault Messages and Error Codes
The boiler control panel LCD screen will also indicate that a fault has
occurred with the boiler by displaying both a ‘Fault Message’ and
‘Error Code’.
Figure 10: Boiler ‘fault message’ and ‘error code’
The following ‘Fault Messages’ and ‘Error Codes’ can be displayed on
the control panel LCD screen:
Fault message Error
code Fault message Error code
Safety relay fault 1 Hopper lid open 16
Failed pellet lighting 2 Burner fan ignition rate 17
Safety charge pipe stat 3 Burner fan failed 18
Overheat thermostat 4 False flame 19
Servo motor blocked 8 EN60730 fault (PCB fault) 20
Flue fan ignition rate 10 Safety flap open 21
Flue fan failed 11 Safety flap closed 22
Water flow switch 12 APS fault 23
Fuel low 13 Safety monitor 24
Safety shutdown 14 Auger monitor fault 24
Door open 15 Ignition monitor fault 24
For further details on the ‘Error Messages’, and what to do if your
boiler will not start, refer to Section 9.
3.3 Information and Service information Display
If required, these displays can be accessed from the ‘Home Screen’
as follows:
• Press button 3(i) once ‘Information’ screen is displayed,
showing
Flame lux: %
Fan Speed: RPM
• Press button 3(i) again ‘Oxygen Level’ screen is displayed,
showing
Target level: %
Actual level: %
• Press button 3(i) again ‘Service Information’ screen is
displayed, showing
Run time: Hrs.
Service in: Hrs.
• Press button 3(i) again to return to ‘Home Screen’ display
Boiler ‘fault message’
Boiler ‘fault message’
Press to reset - refer to Section 9

User Instructions Page 11
This is a built-in safety device, located at the lower front of the boiler
(inside the front door of the boiler). Refer to Figure 11. This will
automatically shut down the boiler in the event of it overheating.
If this device should operate, it will be indicated on the control panel
LCD screen with the fault message ‘Overheat Thermostat’ and error
code 4 will be displayed. The thermostat can be manually reset once
the boiler has cooled down.
To reset:
• Switch the boiler ON/STANDBY switch to STANDBY and allow the
boiler to cool down.
• Open the front door to access the thermostat.
• Unscrew the plastic cap and press the reset button until it clicks
and replace the cap.
• Then press button 3 on the boiler control panel to reset the
controls.
• Switch the boiler ON/STANDBY switch back to ON for the boiler
to operate.
If this thermostat continually operates there may be a fault. If so,
contact your Grant Approved Installer for assistance.
4 Boiler Overheat Thermostat
This is a built-in safety device, located at the lower front of the boiler
(inside the front door of the boiler). Refer to Figure 11. When set to
OFF (O) it isolates all electrical supplies to the boiler.
It must be set to OFF (O) before the combustion chamber door can
be opened to remove the ash pan or clean the boiler.
With the combustion chamber door fully closed it must be set to ON
(I) for the boiler to operate.
5 Electrical Isolator Switch
Figure 11: Overheat thermostat and electrical isolator switch
This is a built-in safety device, located in the pellet feed system within
the boiler. This will automatically shut off the pellet supply, and thus
the boiler, in the event of high temperatures being detected in the
pellet feed system.
To reset: Switch the boiler ON/STANDBY switch to STANDBY and allow
the boiler to cool down. Then press button 3 on the boiler control
panel to reset the controls. If this thermostat continually operates
there may be a fault. If so, contact your Grant Approved Installer for
assistance.
6 Safety Charge Pipe Thermostat
Electrical isolator switch
Boiler overheat thermostat

User InstructionsPage 12
The illuminated Grant logo, on the front of the boiler*, has been
designed to assist the user by clearly indicating the following boiler
conditions:
Logo illuminated (low brightness):
Indicates the following
• The electrical power supply is connected to the boiler and it is
switched on
• There is no demand from the heating system controls for the
boiler to operate
AND/OR
• The ON/STANDBY switch on the boiler control panel is set to
OFF
This does not indicate that the boiler is operating or that the burner is
firing. Refer to Section 8.
Logo illuminated (high brightness):
Indicates the following
• The electrical power supply is connected to the boiler and it is
switched on
• There is a demand from the heating system controls for the boiler
to operate
AND
• The ON/STANDBY switch on the boiler control panel is set to ON
This does not necessarily indicate that the boiler is operating or that
the burner is firing. Refer to Section 8.
Logo flashing (slow flash):
Indicates a low pellet level – when the minimum level of pellets in the
pellet hopper has been reached. Top up pellet hopper without delay.
Refer to Sections 1 and 3.2.7.
Logo flashing (fast flash):
Indicates ash pan needs emptying – empty ash pan without delay.
Refer to Section 11.
* If your boiler is installed in a garage or other outbuilding, it may be
fitted with an optional Remote Grant Logo Indicator (not supplied with
the boiler). This should be located in a convenient and visible position
within your house. This remote Logo Indicator will operate in addition
to the one fitted on the front of the boiler, as described above.
7 The Grant Logo Indicator
To start your boiler
• First, ensure that the electrical supply to the boiler is switched
on and that the electrical isolator switch is set to ON (I). Refer to
Section 5.
• Then check that the heating system controls (programmer and
room thermostat) are operating and are calling for heat. This will
be indicated by the Grant logo (on the front of the boiler) being
illuminated and the ‘Heating Demand’ message being displayed
on the boiler control panel LCD screen. Refer to Figure 12.
• Finally, set the ON/STANDBY switch on the boiler control panel to
ON. The fan will start and pellets will be delivered to the burner
for it to start.
• The boiler will now light automatically after a short ignition period.
• After completing the start-up sequence, the burner should be
firing.
• Initially the boiler will operate at 25% output (indicated by one
segment on the modulation indicator on the control panel LCD
screen) for 25 seconds.
• The output will then increase to 50% for the next 25 seconds
(indicated by two segments), then 75% for 25 seconds (three
segments) and then 100% output (indicated by four segments on
the modulation indicator).
• When the burner is firing the lambda symbol (at the left hand end
of the control panel LCD screen) will be continually flashing to
indicate that the lambda control is operating.
• Set the heating (CH) and hot water (HW) functions on your
programmer to ‘Timed’. The boiler will now operate during the
‘ON’ periods set on the programmer.
T: 69.5°C
SP: 75.0°C
Modulation Level
Heating Demand
Figure 12: LCD ‘heating demand’ message
If the boiler ON/STANDBY switch is set to STANDBY during the
initial pellet pre-load period, the pellet feed will stop and the
burner will go into post purge. The fault message ‘False flame’
(and error code 19) will show on the control panel display
screen. The burner will then complete the shut-down sequence
before it can start-up again, even if the ON/STANDBY switch is
reset to ON.
If the ON/STANDBY switch is set to STANDBY during the start-
up sequence, but AFTER the pellet pre-load is finished, then
the burner will immediately enter and complete the shut-down
sequence before it can start-up again, even if the ON/STANDBY
switch is reset to ON.
NOTE
!
8 Lighting the Boiler
‘Heating demand’ message’

User Instructions Page 13
If you experience a problem with your boiler, it may be due to something quite simple and by making a few checks you can quickly rectify it for
yourself. If your boiler fails to light, please follow the procedure given below, starting with STEP 1:
STEP 1
Is the boiler control panel LCD screen blank?
NO Go to STEP 2
YES Check the following:
• Is the electrical supply to boiler and heating system controls switched on at fused spur?
• Has the fuse in the fused spur blown?
• Is the boiler electrical isolator switch set to ON (I)? Refer to Section 5.
If, after checking the above, there is still a problem then contact your Installer for assistance.
STEP 2
Is there a FAULT MESSAGE on the boiler control panel LCD screen? Refer to Section 3.2.8.
NO Go to STEP 3
YES Go to STEP 4
STEP 3
Is the Grant logo illuminated (high brightness) and ‘Heating Demand’ displayed on the control panel LCD screen?
NO Check the following:
• Is the boiler STANDBY/ON switch set to the ON position? If not, then set it to ON.
• Is there a sufficient quantity of pellets in the pellet hopper? If not, top up the hopper with pellets.
• Are the heating system controls (programmer, room thermostat, etc.) ‘calling’ for heat? If not, set controls to call for
heat.
YES Check the boiler water temperature (T) on the burner control panel LCD screen.
• The boiler water temperature may have exceeded 80˚C.
If so, there is NO fault but the boiler is waiting for the system temperature to drop below the set point (SP)
temperature minus 5˚C before firing again.
If, after checking the above, there is still a problem then contact your Installer for assistance.
STEP 4
Which FAULT MESSAGE is showing on the LCD screen?
Is the fault message one of the following?
• Error Code 14 Safety Shutdown
• Error Code 19 False Flame
• Error Code 20 EN60730 Fault
• Error code 21 Safety Flap Open
• Error Code 22 Safety Flap Closed
NO Go to STEP 5
YES These faults should self-reset. If the fault persists contact your Installer for assistance
STEP 5
Was the fault message FAILED PELLET LIGHTING displayed on the LCD screen?
NO Go to STEP 6
YES Check the following:
• The brazier is not blocked with ash. If so remove all ash from brazier.
• Press button 3 on boiler control panel to reset the control
If, after checking the above, there is still a problem then contact your Installer for assistance.
STEP 6
Was the fault message SAFETY CHARGE PIPE STAT displayed on the LCD screen?
NO Go to STEP 7
YES Press button 3 on boiler control panel to reset the safety charge pipe thermostat
If, after checking the above, there is still a problem then contact your Installer for assistance.
STEP 7
Was the fault message OVERHEAT THERMOSTAT displayed on the LCD screen?
NO Go to STEP 8
YES Check the following:
• Has the boiler overheat thermostat tripped? Remove cap to check.
• If yes, press the thermostat reset button. Refer to Section 4.
• Press button 3 on boiler control panel to reset control
If, after checking the above, there is still a problem then contact your Installer for assistance.
STEP 8
Was the fault message SERVO MOTOR BLOCKED displayed on the LCD screen?
NO Go to STEP 9
YES Check the following:
• Is the brazier blocked with ash/clinker? If yes remove the blockage.
• Press button 3 on boiler control panel to reset control
• Reset STANDBY/ON switch to ON.
• Is the correct grade of pellets being used? If not, empty the hopper and refill with correct grade of pellet.
If, after checking the above, there is still a problem then contact your Installer for assistance.
9 If your Boiler fails to Start

User InstructionsPage 14
STEP 9
Was the fault message FUEL LOW displayed on the LCD screen?
NO Go to STEP 10
YES Check the following:
• Is there a sufficient quantity of pellets in the pellet hopper?
• If not, top up the hopper pellets.
If, after checking the above, there is still a problem then contact your Installer for assistance.
STEP 10
Was the fault message DOOR OPEN displayed on the LCD screen?
NO – Go to STEP 11
YES – Check the following:
• The combustion chamber door is fully closed
• The combustion door catch is fully engaged
If, after checking the above, there is still a problem then contact your Installer for assistance.
STEP 11
Was the fault message HOPPER LID OPEN displayed on the LCD screen?
NO Go to STEP 12
YES Check the hopper lid is fully closed
If, after checking the above, there is still a problem then contact your Installer for assistance.
STEP 12
Was the fault message FLUE FAN IGNITION RATE displayed on the LCD screen?
NO Go to STEP 13
YES Press button 3 on the boiler control panel to reset
If, after checking the above, there is still a problem then contact your Installer for assistance.
STEP 13
Was the fault message FLUE FAN FAILED displayed on the LCD screen?
NO Go to STEP 14
YES Press button 3 on the boiler control panel to reset
If, after checking the above, there is still a problem then contact your Installer for assistance.
STEP 14
Was the fault message APS FAULT displayed on the LCD screen?
NO Go to STEP 15
YES Check the following:
• Switch the boiler isolator switch to OFF and then back to ON
• On power up, the fault should self-reset
• If not press button 3 on the boiler control panel to reset
If, after checking the above, there is still a problem then contact your Installer for assistance.
STEP 15
Was the fault message SAFETY MONITOR displayed on the LCD screen?
NO Go to STEP 15
YES Press button 3 on the boiler control panel to reset
If, after checking the above, there is still a problem then contact your Installer for assistance.
Do not under any circumstances enter a bulk pellet store or
pellet hopper that has been in operation, because if the boiler
has malfunctioned, there may be a build-up fumes within the
enclosure.
!WARNING

User Instructions Page 15
It is essential that the ash pan is emptied when indicated by the Grant
logo, on the front of the boiler, and the optional Remote Grant logo
Indicator (if fitted), is flashing (fast flash).
The amount of ash produced varies between the different pellet
brands and this will affect the frequency of cleaning and maintenance
required.
A multi-purpose tool is supplied with the boiler for servicing and
cleaning. This is used for the following functions:
• As the door catch handle – required to open the combustion
chamber door
• As the ash pan carrying handle – required to remove the ash pan
from the boiler
• To open the brazier catch
• To remove the brazier front plate
• To remove the brazier base plate
• To remove the brazier cotter pin
The multi-purpose tool is hung on a hook located on the panel to the
left of the combustion chamber door. Always replace the tool back on
this hook after use to ensure it is available when next required.
*An ash pan carrying handle is also supplied with the boiler. This must
be used in conjunction with the multi-purpose tool, to support the
opposite end of the ash pan, when removing it from the boiler. Refer to
Figure 15.
After the boiler has been switched off (either manually, using
the ON/STAND-BY switch on the control panel, or automatically
by the boiler or the heating system controls) the burner needs
to burn-down the remaining pellets in the brazier. Do NOT open
the front combustion chamber access door AT ANY TIME until
‘Standby’ is showing on the control panel LCD screen.
!WARNING
To empty the ash pan simply follow this procedure:
• Set the boiler STANDBY/ON switch to ‘STANDBY’.
• If the boiler is running at the time, wait for it to complete the
burner shut-down sequence, i.e. until ‘Standby’ is displayed on
the control panel LCD screen.
• Wait for the boiler to cool down.
• Unlock the front door of the boiler with the key provided. Pull out
door catch handle and rotate handle anticlockwise to unlatch
and open the door.
• Set the electrical isolator switch to OFF (O). Refer to Figure 11.
• Fit the multi-purpose tool (provided with the boiler) into slot in
the combustion door catch (on the left side of the door). Refer to
Figure 13.
• Lift handle to release the catch and fully open the combustion
chamber door. Refer to Figure 14.
11 Emptying the Ash Pan
The boiler MUST be serviced either ANNUALLY or when the ‘Service’
message is displayed on the control panel LCD screen (refer to
Section 3.2.6), whichever comes FIRST.
The ash pan (located inside the boiler combustion chamber)
MUST be periodically emptied by the user. This simple task
must be carried out when indicated by the Grant logo on the
front of the boiler, and the optional Remote Grant logo Indicator
(if fitted), is flashing (fast flash). Refer to Section 7.
!CAUTION
The amount of ash produced varies between the different
pellet brands and this will affect the frequency of cleaning and
maintenance required.
NOTE
!
Servicing should only be carried out by a Grant trained Installer
or Grant Service Engineer, and details of each service should be
recorded in the Service Log - in Section 16 of these User Instructions.
Failure to maintain a clean flue may result in the release of flue
gases into the dwelling or damage from potential fire in the
flue. It is therefore essential that your flue is cleaned annually
by either a Grant trained installer or a suitably qualified
chimney sweep.
!CAUTION
10 Cleaning and Servicing your Boiler

User InstructionsPage 16
Figure 13: Multi-purpose tool and door catch
Figure 14: Open combustion chamber door
The electrical isolator switch and combustion chamber door
switch automatically disconnects the power supply to the
burner if the combustion chamber door is opened. THIS DOES
NOT IMMEDIATELY EXTINGUISH THE BURNER FLAME. If the
combustion chamber door is opened during or shortly after the
operation of the burner there can still be a large flame from the
brazier.
!WARNING
Using the multi-purpose tool provided with the boiler, carefully pull the
ash pan forward and remove it from the boiler. Refer to Figure 15.
• When carrying the ash pan, use both the multi-purpose tool and
the ash pan carrying handle (also provided with the boiler). Refer
to Figure 16.
• The ash pan, once removed, can only be replaced one way. If
replaced incorrectly the combustion door cannot be closed.
• Remove any remaining ash that may be left in the base of the
boiler before putting the ash pan back into the combustion
chamber.
• Close the combustion chamber door and ensure that the door
catch is fully engaged.
Figure 15: Removal of ash pan from boiler
Extreme care is required when empting the ash pan as
smouldering ash could be present and can cause serious
damage to persons or property. Ensure the ash is disposed of
in a safe manner.
!WARNING
Figure 16: Removal of ash pan from boiler
Ash pan carry handle
Multi purpose tool

User Instructions Page 17
As an ‘open flued’ appliance, the Grant Vecta boiler draws the air
required for combustion from the room in which it is located. In turn,
this air comes from outside via a permanently open air vent (or vents)
correctly sized to meet the air requirements of your boiler.
Any permanently open combustion air vents in the room
containing the boiler MUST NOT be blocked off or obstructed
in any way. Do not attempt to ‘box in’ the boiler, or build a
compartment around it, before contacting your Installer for
guidance.
!WARNING
Do NOT place any combustible material against, around or on the
boiler or flue pipe. The combustion air inlet to the boiler is provided by
the gap along the bottom edge of the door.
This opening must not be blocked off or obstructed in any way.
Current Building Regulations require that a Carbon Monoxide
alarm (conforming to BS EN 50291-2:2010) must be fitted in the
room where the boiler is located. This should be positioned
between 1m and 3m horizontally from the boiler either:
a) On the ceiling at least 300mm from any wall, or
b) On a wall as high up as possible (above any windows or
doors) at least 150mm from ceiling
NOTE
!
12 Ventilation
If the electricity supply fails, the boiler will cease to operate. It should
automatically relight when the electrical supply is restored. However,
it may first burn off any smouldering pellets still present in the brazier
before starting the lighting sequence again.
If a remote programmer is connected to your boiler, it may have a
‘battery back-up’ of some kind that will retain the on/off time settings
you previously entered. It may also resume operation with the correct
time of day and thus require no re-setting of time and on/off settings
when the supply is restored. Refer to the instructions supplied with
your programmer for further details. It is recommended that you check
that the on/off and time setting after a power failure has occurred.
13 Electricity Supply
The electricity connections to the boiler must be earthed.
!WARNING

User InstructionsPage 18
Your installer may have fitted a frost thermostat. If not, and you are
likely to be away for a short time, leave the boiler on with the room
thermostat set at a low setting. For longer periods, the boiler should
be turned off and the system drained down. Contact your Installer for
draining and re-filling the system.
If your boiler is installed in a garage or out house, a combined anti-
freeze and corrosion inhibitor can be used to protect the system and
boiler from freezing should there be a power failure in cold weather.
15 Frost Protection
Grant UK recommends that corrosion inhibitor and a Grant
Mag-One magnetic filter should be used in the primary water
system.
NOTE
!
If your boiler is operating on a sealed heating system, the installer will
have adjusted the pressure in the system and should have told you
the system pressure (when cold) or set it on the pressure gauge. This
is normally between 0.5 and 1.0 bar, which will increase slightly when
hot. If the pressure (when cold) is below the set pressure mentioned
above, you can re-pressurise the system. If this is frequently required,
ask your Installer or service engineer to check the heating system for
leaks and to check the expansion vessel air charge.
The boiler or system will be fitted with an automatic air vent to remove
any air from the system. Any trapped air in the radiators should be
removed by venting the radiators using the vent screw at the top of
each radiator. Only vent a radiator if the top is cool and the bottom is
hot.
Excessive venting will reduce the system pressure, so only vent when
necessary and check the system pressure as mentioned above. Re-
pressurise the system as necessary.
The sealed system is fitted with a safety valve to release
excess pressure from the system. If water or steam is emitted
from the end of the safety valve discharge pipe, switch off the
boiler and contact your Installer for assistance.
!CAUTION
To re-pressurise the System by adding water
The procedure is as follows:
• Identify the location of the filling connection and the
pressure gauge on the heating system.
• Ensure the flexible filling loop is connected and that the shut
off valve connecting to the heating system is open and the
double check valve (on the cold water supply) is closed.
• A valve is open when the operating lever is in line with the
valve and closed when it is at right angles to it.
• Gradually open the double check valve until the water is
heard to flow.
14 Sealed Heating System
• Fill the system until the pressure gauge indicates the
required pressure (between 0.5 and 1.0 bar) and then close
the double check valve.
• Vent each radiator in turn, starting with the lowest one on the
system to remove any air.
• Check the pressure gauge. If necessary, open the double
check valve to top up the system pressure to the required
value and then close the double check valve.
• Check the valves on either side of the filling loop are closed
and disconnect the loop.
Only add water to the system when it is cold and the boiler and
pump is switched off. Do not overfill.
!WARNING
Corrosion Inhibitor
For long term protection against corrosion and scale, a suitable
inhibitor should be added to the system water, such as Sentinel X100
or Fernox MB-1, in accordance with the manufacturers’ instructions.
Failure to follow the above will invalidate the guarantee.
If your heating system has been topped up several times, or drained
down and re-filled, it will be necessary to add corrosion inhibitor to
protect against corrosion and scale in the radiators and boiler.
However, if a combined anti-freeze and corrosion inhibitor was
originally added to your heating system, it will be necessary to add
this to maintain the required level of frost protection as well as protect
against corrosion and scale in the radiators and boiler.
Check with your Installer or Service engineer for guidance.
To protect the boiler and system from sludge build-up, Grant
recommends the use of an in-line magnetic filter, such as the Grant
Mag-One magnetic filter, installed in the heating return close to the
boiler. This filter must be cleaned out as part of every boiler service.

User Instructions Page 19
Service 1 Service 2 Service 3 Service 4 Service 5
Heating System
System pressure – check/top up
Pressure relief valve operation - check
Expansion vessel charge pressure – check
Magnetic filter – inspect/clean
Corrosion inhibitor in system – check
Flue System
Flue terminal – check condition
Flue system – check clean
Smoke test (Smoke test II Part J. Section E15)
Combustion ventilation – check
Boiler
Temperature probe – check
Overheat thermostat – check
Primary heat exchanger – inspect/clean
Shaker system – check operation
Fan – inspect/clean
Combustion chamber – inspect/clean
Secondary heat exchanger – inspect/clean
Wash system – inspect/clean
Condensate trap – inspect/clean
Condensate discharge pipe – inspect/clean
Burner
Brazier – dismantle/clean
Photocell – inspect/clean
Boiler settings – check
Safety devices
Hopper lid switch – check operation
Combustion door switch – check operation
Pellet Hopper
Check for dust build-up
Auger – check for blockages
Combustion
Combustion chamber draught – check/record
Flue gas analysis – check/record
Customer handover
Service Date
Service Company
Signature
16 Service Log

GRANT ENGINEERING (UK) LIMITED
Hopton House, Hopton Industrial Estate, Devizes, Wiltshire, SN10 2EU
Tel: [phone] Fax: [phone]
Email: [email protected] www.grantuk.com