Worcester Greenstar 9i System ErP User manual

UK/IE
User instructions
Wall hung RSF gas fired condensing system boiler
Greenstar i System ErP
6720806946-00.1Wo
For sealed central heating systems
6 720 806 947 (2015/03)
If you smell gas:
▶ Well away from the building: call the National Gas Emergency
Service on 0800 111 999.
▶ L.P.G. boilers: Call the supplier’s number on the side of the
gas tank.
These appliances are for use with:
Natural Gas or L.P.G.
(Cat. II 2H 3P type C13, C33 & C53)
Model GC Number
Natural Gas Greenstar 9i System ErP 41-406-21
Greenstar 12i System ErP 41-406-23
Greenstar 15i System ErP 41-406-25
Greenstar 18i System ErP 41-406-27
Greenstar 21i System ErP 41-406-29
Greenstar 24i System ErP 41-406-31
L.P.G. Greenstar 9i System ErP 41-406-22
Greenstar 12i System ErP 41-406-24
Greenstar 15i System ErP 41-406-26
Greenstar 18i System ErP 41-406-28
Greenstar 21i System ErP 41-406-30
Greenstar 24i System ErP 41-406-32

2
Preface
Greenstar i System ErP – 6 720 806 947 (2015/03)
Preface
Please read these instructions carefully
These instructions are applicable to the Worcester, Bosch
Group appliance model stated on the front cover only.
These instructions apply in the UK/IE only and must be followed
except for any statutory obligation.
After installation please leave this User instruction Manual,
Installation, Commissioning and Servicing Instructions and
completed Benchmark Checklist with the user.
Dedicated to heating comfort
Thank you for purchasing a Greenstar gas-fired condensing
appliance manufactured by Worcester, Bosch Group. The
company prides itself on manufacturing appliances to the
strictest quality control standards throughout every stage of
production.
Worcester, Bosch group has led the field in innovative
appliance design and performance for over 50 years. This
heritage means all our products are of exceptional quality and
proven reliability.
The Greenstar range in particular is extremely energy efficient,
offering you economical running costs and value for money. It is
amongst the top energy rated appliances available.
There is also the reassurance of our parts and labour guarantee
- backed up by Worcester Total Cover, an optional complete
maintenance scheme to keep your appliance operating at peak
condition and efficiency.

3
Contents
Greenstar i System ErP– 6 720 806 947 (2015/03)
Contents
1 Key to symbols and safety instructions . . . . . . . . . . . . 4
1.1 Key to symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2 Safety precautions . . . . . . . . . . . . . . . . . . . . . . . . 4
2 General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1 Energy efficiency . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2 Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.3 Benchmark standard . . . . . . . . . . . . . . . . . . . . . . 5
2.4 User caution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3 Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1 Appliance controls . . . . . . . . . . . . . . . . . . . . . . . . 8
3.1.1 Appliance display . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.1.2 Basic adjust mode . . . . . . . . . . . . . . . . . . . . . . 12
3.2 Central heating . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.2.1 View appliance flow set temperature . . . . . . . 13
3.2.2 Setting the appliance flow temperature
for the system . . . . . . . . . . . . . . . . . . . . . . . . . .13
3.2.3 Set economic temperature - Central
heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
3.2.4 Turning the central heating off during the
summer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
3.2.5 Appliance frost protection . . . . . . . . . . . . . . . 14
3.3 No integral diverter valve fitted:
Cylinder temperature adjustment . . . . . . . . . .15
3.4 Optional integral diver valve kit fitted:
Setting the cylinder hot water temperature . .15
3.4.1 View the cylinder hot water temperature set
temperature . . . . . . . . . . . . . . . . . . . . . . . . . . .15
3.4.2 General cylinder hot water temperature
adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
3.4.3 Mid point domestic hot water temperature . . 16
3.4.4 Domestic hot water eco and preheat modes . 17
3.4.5 Domestic hot water preheat mode manual
activation (Eco mode off) . . . . . . . . . . . . . . . . .17
3.4.6 Turn off the operation/fault diagnostic
light (blue) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
4 System pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.1 External filling link . . . . . . . . . . . . . . . . . . . . . . 18
5 Clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6 Maintaining your appliance . . . . . . . . . . . . . . . . . . . . 20
7 Fault finding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
7.1 Appliance alert state . . . . . . . . . . . . . . . . . . . . 22
7.2 Appliance reset . . . . . . . . . . . . . . . . . . . . . . . . 22
7.3 Extreme cold weather . . . . . . . . . . . . . . . . . . . 23
8 Fault or breakdown . . . . . . . . . . . . . . . . . . . . . . . . . . 23
9 Tips on energy saving . . . . . . . . . . . . . . . . . . . . . . . . 24
10 Environment/disposal . . . . . . . . . . . . . . . . . . . . . . . . 25
11 Your guarantee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
12 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

4
Key to symbols and safety instructions
Greenstar i System ErP – 6 720 806 947 (2015/03)
1 Key to symbols and safety instructions
1.1 Key to symbols
Warnings
The following keywords are defined and can be used in this
document:
•NOTICE indicates a situation that could resultin damage to
property or equipment.
•CAUTION indicates a situation that could result in minor to
medium injury.
•WARNING indicates a situation that could result in severe
injury or death.
•DANGER indicates a situation that will result in severe
injury or death.
Important information
Additional symbols
Examples of additional symbols used
A numbered step in an action sequence
A sequence of numbered steps or actions carried out in a
specific order to complete a task.
1. First action
2. Second action
3. Third action
etc.
A step in an action sequence
A sequence of defined actions or steps carried out in order to
complete a task.
▶Action
▶Nextaction
▶etc
A reference to a related part in the document or to other
related documents.
To refer the reader to a specific figure/table/section within the
manual.
e.g. figure 1.
A reference number to identify or refer to a part or item.
In a related figure, items or parts identified by a sequential
number.
List entries, first and second levels
• A single component/item
• A component/list, made up of multiple parts/items.
– Sub component or sublist of main component/list.
–etc.
1.2 Safety precautions
If you smell gas:
A gas leak could potentially cause an explosion. If you smell gas,
observe the following rules.
▶ Prevent flames or sparks:
– Do not smoke, use a lighter or strike matches.
– Do not operate any electrical switches or unplug any
equipment.
– Do not use the telephone or ring doorbells.
▶ Turn off the gas at the meter or regulator.
▶ Open windows and doors.
▶ Warn your neighbours and leave the building.
▶ Prevent anyone from entering the building.
▶ Well away from the building: call the National Gas
Emergency Service on 0800 111 999.
▶ L.P.G. boilers: Call the supplier’s number on the side of the
gas tank.
Appliance operation:
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 the 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.
Safety instructions in this document are
framed and identified by a
warning triangle which is printed on a grey
background.
This symbol indicates important information
where there is no risk to people or property.
Symbol Meaning
1. a numbered step in an action sequence
▶ a step in an action sequence
a reference to a related part in the document or to
other related documents
a reference number to identify or refer to a part or
item
•alistentry
– a list entry (second level)
Table 1
1

5
General information
Greenstar i System ErP– 6 720 806 947 (2015/03)
Combustible and corrosive materials:
Chemically aggressive substances can corrode the appliance
and invalidate any guarantee.
• Do not store or use any combustible materials (paper,
thinners, paints, propellants, cleaning agents etc.) inside
the cupboard containing the appliance or within the vicinity
of the appliance.
Fittings and modifications:
Only a competent engineer can remove the appliance case and
carry out any work, in accordance with the Gas Safety
(Installation and Use) Regulations.
• Do not remove the appliance case.
Any misuse or unauthorised modifications to the appliance,
flue or associated accessories and heating system will
invalidate the guarantee.
• Do not modify the appliance or flue system in any way.
Worcester, Bosch Group accepts no liability arising from any
such actions. This does not affect your statutory rights.
Cleaning the appliance case:
Use a damp, soft cloth to clean the outer painted metal case of
the appliance, do not use chemicals or abrasive materials.
2 General information
2.1 Energy efficiency
Energy efficiency information is given in the Installation,
Commissioning and Servicing Instructions supplied with the
appliance.
2.2 Servicing
• The appliance must be serviced regularly by a competent,
qualified person, such as a Worcester service engineer or
other Gas Safe registered engineer.
• Always use original spares, to help maintain the efficiency,
safety and reliability of the appliance and have the Service
Record completed in the Benchmark Checklist.
The completed Benchmark Checklist will be required in the
event of any guarantee work and may be required by the local
Building Control Inspector.
2.3 Benchmark standard
The Benchmark initiative is a
code of practice to encourage
the correct installation,
commissioning and servicing of
domestic central heating
appliances and system
equipment.
A “checklist” is dispatched with every appliance and can be
found towards the back of the Installation, Commissioning and
Servicing Instructions. This is a vital document that needs to be
completed by the installer at the time of installation. It confirms
that the appliance has been installed and commissioned
according to the manufacturer's instructions.
The service record provides space for the recording of regular
servicing of the appliance/heating system and this can become
a valuable document when, for example, you wish to sell the
property. The service record will show a potential purchaser
that the heating system has received regular professional
maintenance and servicing during its lifetime.
The Benchmark initiative aims to:
• Raise standards among professional installers
• Build and maintain high safety standards in the industry
• Improve customer satisfaction levels
• Make a contribution to the nation's commitment to climate
change
2.4 User caution
• It isforbidden for any interference with the appliance other
than those actions allowed in this document.
Ensure that the service engineer completes
the Service Record in the Benchmark
Checklist after each service. The Benchmark
Checklist and service interval record can be
found at the rear of the Installation,
Commissioning and Servicing Instructions.
CAUTION: Incorrect use
▶ Any incorrect use can result in danger to
the householder.

6
Controls
Greenstar i System ErP – 6 720 806 947 (2015/03)
3Controls
Fig. 1 Appliance control panel
Item Description
1Systempressuregauge
• Displays pressure in the heating system and appliance
2 Position for optional programmer
• Worcester plug in controls position
3ECO/OKbutton
• Dual function button
– ECO (toggles domestic hot water preheat ON/OFF)
–OK(menuconfirmation)
4 Info/Return/Spanner button
• Multi function button
– Info (Information menu access)
– Return (return to previous screen)
– Spanner (engineer function)
5 Appliance display
• Temperature and information display
6 Reset/Service engineer button
• Dual function button
– Reset (appliance reset)
– Service engineer (engineer service and set up function)
Table 2 Legend to figure 6
6720806946-01.1Wo
123456
11
12
10 9
7
8

7
Controls
Greenstar i System ErP– 6 720 806 947 (2015/03)
7 Cylinder hot water settings increase temperature/menu scroll up button
• Dual function button
– Increase temperature (increase the desired hot water temperature), this function is only available if the
optional integral diveter valve kit is fitted.
– Menu scroll up (scroll upwards through menu items)
8 Cylinder hot water settings decrease temperature/menu scroll down button
• Dual function button
– Decrease temperature (decrease the desired hot water temperature), this function is only available if the
optional integral diveter valve kit is fitted.
– Menu scroll down (scroll downwards through menu items)
9 Central heating settings decrease button
• Decrease temperature (decrease the desired flow temperature)
10 Central heating settings Increase button/Increase button
• Increase temperature (increase the desired flow temperature)
11 Heat requirement demand and fault indicator (blue)
• Dual function
– Heat requirement demand (illuminates during a central heating or hot water requirement demand)
– Fault indicator (flashes during a fault condition)
12 Appliance identification label
• Details on appliance model, serial number and gas council number
Item Description
Table 2 Legend to figure 6

8
Controls
Greenstar i System ErP – 6 720 806 947 (2015/03)
3.1 Appliance controls
Fig. 2 Display (example in standby with Eco mode active) and buttons
[1] Display Screen
[2] Eco mode active display message
[3] User function buttons:
•Ecobutton( )
– Manually select Economy or Pre-Heat mode
• Info button ( )
– Access to Info menu Function
• Reset button ( )
– Appliance reset button
[4] Menu functions buttons:
•OKbutton( )
–Confirmsaselection
•Backbutton( )
– To return to the previous option or menu
[5] Engineer function buttons:
• Spanner button ( )
– Service menu function button only
• Chimney sweep button ( )
– Engineer service and set up function only
[6] Central heating flow temperature adjustment buttons:
• Increase button ( )
–Increasevalue
•Decreasebutton( )
– Decrease value
[7] Cylinder hot water maximum temperature adjustment
buttons, this function is only available if the optional
integral diveter valve kit is fitted. (These buttons are also
used in menu /scroll/adjustment, indicated by arrows on
right of text display line):
• Increase button ( )
–Increasevalue
•Decreasebutton( )
– Decrease value
6720806946-02.1Wo
Eco
4
6
1
2
7
3
5

9
Controls
Greenstar i System ErP– 6 720 806 947 (2015/03)
3.1.1 Appliance display
SCREEN DISPLAY DESCRIPTION
All possible screen symbols This screen is displayed briefly during appliance start up and shows all the symbols
that could be displayed.
Alpha/Numerical display Displays a temperature or appliance status code.
Text display Displays status, diagnostic code and short description information.
Right hand arrows (text display) Use domestic hot water arrow buttons to alter the menu item.
Flashing T (text display) Appliance in component test mode.
Flashing A (text display) Appliance in air purge mode.
Hot water Displays this symbol during cylinder hot water demand, when controlled with
Worcester intelligent controls in conjunction with the optional integral diverter valve
kit.
Central Heating Displays this symbol during a central heating use.
Chimney sweep mode Displays during service when the appliance is set to maximum or minimum output.
Table 3 Symbol description
6720806944-32.1Wo

10
Controls
Greenstar i System ErP – 6 720 806 947 (2015/03)
Alert Displays with the appliance status code and diagnostic code during a fault
condition.
Service mode Displays when a qualified service engineer is in the service menus.
Burner on The appliance is in operation and the flame is alight.
Centigrade Displays next to the temperature reading.
Confirmation This symbol confirms a setting change.
Table 3 Symbol description
°C

11
Controls
Greenstar i System ErP– 6 720 806 947 (2015/03)
Info menu and operational status codes
These are not faults, but provide information concerning the current status of the appliance.
During normal appliance operation various Status codes can be displayed by pressing the button.
The first screen of the Information menu displays the current Status code, this will change as the appliance runs through the various
modes and sequences.
Info menu No. Description
i1 Current status
• Appliance current operating status (see table 5 for operational status codes).
i2 Previous status
• Appliance previous operating status (see table 5 for operational status codes).
i4 Maximum cylinder output (kW)
• Maximum cylinder output (kW) set on the appliance.
i8 Ionization current
• Measured ionisation current (μA).
i9 Flow temperature
• Measured primary flow temperature of the appliance ( °C).
i11 Domestic hot water outlet temperature
• Measured DHW flow temperature of the appliance ( °C).
i12 Cylinder set temperature
• Displays the current set temperature for the cylinder (only available when using the optional integral
diverter valve kit).
i13 Cylinder temperature
• Measured cylinder sensor temperature (°C) (only available when using the optional integral diverter valve
kit).
i15 Outdoor sensor
• Temperature reading from outdoor temperature sensor, (only available if an outdoor sensor accessory is
fitted)
i20 CU version
• Software version of the control box
i21 HMI version
• Software version of the HIS (Human Interface Software).
i22 HCM version
• Identification number of the HCM (Heating Control Module) and release version.
Table 4 Info menu

12
Controls
Greenstar i System ErP – 6 720 806 947 (2015/03)
These are not faults, but provide information concerning the current status of the appliance.
During normal appliance operation various Status codes can be displayed by pressing the button.
The first screen of the Information menu displays the current Status code, this will change as the appliance runs through the various
modes and sequences.
3.1.2 Basic adjust mode
Status code Description
200 Central heating system is being heated.
201 Domestic hot water system is being heated (only available when using the optional integral diverter valve kit).
202 Anti rapid cycle mode.
• The boiler has commenced anti-cycle period for central heating. Can be adjusted in boiler settings (2.3b).
• Default 5 Minutes
203 System stand by
204 System waiting, appliance waiting for heating system to cool.
208 Appliance in service Test mode (Min/Max)
265 EMS intelligent controller has forced stan-by-mode due to low heating load.
• The appliance is compensating for the power required from the EMS room controller is less than the
minimum output of the boiler (only available when using EMS intelligent controls with the optional integral
diverter valve kit).
268 Component test mode.
• Appliance is running the manual component test as activated in the menus.
270 Power up mode.
• (appliance is powering up).
283 Burner starting.
• The boiler prepares for a burner start. The fan and the pump are being controlled.
284 Gas valve(s) opened, flame must be detected within safety time.
• The boiler prepares for a burner start. The gas valve is being controlled.
305 Anti fast cycle mode (domestic hot water keep warm function).
• Diverter valve is held in hot water position for a period of time (determined by the software) after hot
water demand (only available when using the optional integral diverter valve kit).
357 Appliance in air purge mode.
• Primary heat exchanger air venting program active - approximately 100 seconds.
358 Three way valve kick.
• If the 3-way valve hasn't moved in within 48 hours, the valve will operate once to prevent seizure (only
available when using the optional integral diverter valve kit).
Table 5 Operational status codes
If you see basic adjust mode in the home screen when attempting to make temperature adjustments, the
appliance has been optimised for your heating system and should not need adjustment.
Please use your room thermostat to adjust your heating temperature if you still cannot achieve the desired room
temperature the Installation, Commissioning and Servicing Instructions contain details on how to disable the
basic adjust mode; this will allow further adjustment of the appliances settings.

13
Controls
Greenstar i System ErP– 6 720 806 947 (2015/03)
3.2 Central heating
3.2.1 View appliance flow set temperature
The home screen will show the current appliance temperature [1].
▶ Briefly press either central heating adjustment buttons.
The display will change to the set temperature for the central heating [2].
▶ Press the OK button to confirm that the set temperature has been viewed, the display will also return to home screen [3].
-or-
▶ Wait 4 seconds and the display will return to the home screen [3].
Fig. 3 Viewing appliance set temperature
3.2.2 Setting the appliance flow temperature for the system
The home screen will show the current appliance temperature [1].
▶ Press the central heating increase or decrease adjustment buttons to select the desired flow temperature.
The temperature displayed increases [2] /decreases [3] according to the adjustment made.
By holding the increase/decrease button the temperature displayed begins to change by larger increments.
▶ Press the OK button to confirm the value selected, the display will also return to the home screen [4].
-or-
▶ Wait 4 seconds for auto confirm and the display will return to the home screen [4].
Fig. 4 Adjust appliance flow temperature
6720806946-03.1Wo
Eco
1
Eco
Wait 4 seconds
2 3
Eco Eco
6720806946-04.1Wo
Wait 4 seconds
for auto confirm
1 3 42

14
Controls
Greenstar i System ErP – 6 720 806 947 (2015/03)
3.2.3 Set economic temperature - Central heating
This setting ensures that the appliance will operate efficiently and is suitable for most heating system.
The home screen will show the current appliance temperature [1].
▶ Press both the central heating adjustment buttons.
The display will change to the economic value for the central heating [2].
▶ Press the OK button to confirm the value selection, the display will also return to the home screen [3].
-or-
▶ Wait 4 seconds for auto confirm and the display will return to the home screen [3].
Fig. 5 Central heating economic temperature
3.2.4 Turning the central heating off during the summer
▶ To turn your central heating off during warm periods:
▶ Set the programmer to OFF
-or-
▶ Turn the room thermostat temperature down to minimum.
3.2.5 Appliance frost protection
If you are leaving your property unoccupied during cold weather, please leave your programmer on constant and your room
thermostat set to 15°C.
▶ If the temperature within the appliance falls below 8°C the pump will run to circulate water and prevent the system freezing.
– If the temperature does not rise to 9°C within 30 minutes of the pump operating, the appliance will fire up.
▶ If the temperature within the appliance falls below 5°C the appliance will fire immediately, bringing the appliance temperature
up to 12°C to avoid the possibility of the appliance freezing.
▶ This process will be repeated until such time that the appliance temperature does not drop below 8°C.
Eco
6720806946-05.1Wo
Wait 4 seconds
for auto confirm
1
2
Do not switch the appliance off at the mains fused spur.

15
Controls
Greenstar i System ErP– 6 720 806 947 (2015/03)
3.3 No integral diverter valve fitted: Cylinder temperature adjustment
If the domestic hot water adjustment buttons or “eco” button is pressed:
• N/A is displayed briefly
• This function will not affect the cylinder hot water temperature.
To adjust the water temperature of the cylinder:
▶ Adjust the cylinder temperature thermostat on the cylinder.
3.4 Optional integral diver valve kit fitted: Setting the cylinder hot water temperature
3.4.1 View the cylinder hot water temperature set temperature
The home screen will show the current appliance temperature [1].
▶ Briefly press either hot water adjustment buttons.
The display will change to the set temperature for the hot water [2].
▶ Press the OK button to confirm the set temperature has been viewed, the display will also return to the home screen [3].
-or-
▶ Wait 4 seconds and the display will return to the home screen [3].
Fig. 6 Viewing hot water set temperature
An external timer may be fitted instead of an internal timer.
An internal or external timer/programmer coupled with the optional integral diverter valve kit with cylinder
temperature sensor is required to be able to set the hot water temperature.
If an FR110, FW100 and Sense II controller is also fitted, in conjunction with the diverter valve, they assume control
over the delivered temperatures, reducing the effect of the temperature controls. Set both to maximum.
6720806946-06.1Wo
Eco
1
Eco
Wait 4 seconds
2 3

16
Controls
Greenstar i System ErP – 6 720 806 947 (2015/03)
3.4.2 General cylinder hot water temperature adjustment
The home screen will show the current appliance temperature [1].
▶ Press the hot water increase or decrease adjustment buttons to select the desired hot water flow temperature.
The temperature displayed increases [2] /decreases [3] according to adjustment made.
By holding the desired increase/decrease button the temperature displayed begins to change by larger increments.
▶ Press the OK button to confirm the value selected, the display will also return to the main screen [4].
-or-
▶ Wait 4 seconds for auto confirm and the display will return to the main screen [4].
Fig. 7 Adjust hot water flow temperature
3.4.3 Mid point domestic hot water temperature
The mid point sets the maximum temperature for the cylinder to 50 °C.
The standard display will show the current requested cylinder temperature [1].
▶ Press both the hot water adjustment buttons.
The display will change to the mid point temperature for the cylinder [2].
▶ Press the OK button to confirm the value selected, the display will also return to main screen [3].
-or-
▶ Wait 4 seconds for auto confirm and the display will return main screen [3].
Fig. 8 Hot water economic value
Eco Eco
6720806946-07.1Wo
Wait 4 seconds
for auto confirm
1 3 42
Eco
6720806946-08.1Wo
Wait 4 seconds
for auto confirm
2
1

17
Controls
Greenstar i System ErP– 6 720 806 947 (2015/03)
3.4.4 Domestic hot water eco and preheat modes
• Eco mode is an energy saving feature which disables the Preheat function:
– Eco is enabled by default, during the initial appliance start up and Eco is displayed.
– During the ON periods set by the time control, the appliance will heat the cylinder If the temperature is approximately 10 °C
below the set temperature.
• Preheat mode, the appliance heats the cylinder more frequently. This tops up the cylinder temperature for quicker heat up
times, this is useful for large/longer demand periods during the hot water ON periods.
– During the ON periods set by the time control, the appliance will heat the cylinder if the temperature is approximately 5 °C
below the set temperature.
3.4.5 Domestic hot water preheat mode manual activation (Eco mode off)
Eco mode active [1]:
▶ Press the eco button (approximately 1 second) to enter the Preheat mode, when Preheat mode is active, “Preheat” will be
displayed [2].
▶ To exit Preheat mode and return to Eco, press the eco button (approximately 1 second), Eco will be displayed [3].
Fig. 9 Manual activation of preheat/eco mode
3.4.6 Turn off the operation/fault diagnostic light (blue)
You may choose to deactivate the heat requirement demand light. Please ask your installer to set-up this feature.
The light will still flash to alert you to a possible fault, but will not activate during a heat requirement demand for heating or hot water.
Eco Eco
Preheat
6720806946-09.1Wo
1 2 3

18
System pressure
Greenstar i System ErP – 6 720 806 947 (2015/03)
4Systempressure
4.1 External filling link
This appliance is fitted to a sealed heating system which is pressurised. Your installer will advise you of the minimum and maximum
pressure indicated on the pressure gauge.
▶ Check regularly that the pressure is maintained.
▶ If the pressure gauge reads less than 1 bar then the system requires re-charging.
▶ Contact your installer or maintenance engineer if a permanent significant decrease or increase in pressure is indicated on the
pressure gauge.
Once the external filling loop has been located, follow the instructions for re-pressurising the system.
1. Unscrew blanking cap.
2. Attach the hose to the valves, screw on hand-tight.
3. Turn the handle/screwdriver slot through 90° to open the valves.
4. The handle/screwdriver slot will be in-line with the valves
Fig. 10 External filling loop
5. When the pressure reaches between the 1 and 1.5 bar marks (zone A), turn the handle/screwdriver slot back, through 90°, to
close the valve.
6. The handle/screwdriver slot will be at 90° to the valves
7. Remove the hose and replace the blanking caps.
2
3
1
04
bar
1
A
Min
1 bar
1.5 bar
Max
6720806947-01.1Wo
1. 2.
7.
4. 4.
3.
3.
6. 6.
5.
5.

19
Clearances
Greenstar i System ErP– 6 720 806 947 (2015/03)
5 Clearances
Your installer will have provided adequate space around the appliance for safety and servicing access.
Fig. 11 Unventilated compartment
[*] Minimum clearances to removable door
[**] Minimum clearances required for servicing
[***] Height for either 60/100 flue or 80/125 flue
CAUTION: Restricted space.
The appliance may overheat.
▶ Do not restrict this space with the addition of cupboards, shelves etc. next to the appliance.
NOTICE: Combustible and corrosive materials:
Chemically aggressive substances can corrode the appliance and invalidate any guarantee.
▶ Do not store or use any combustible materials (paper, thinners, paints, propellants, cleaning agents etc.)
inside the cupboard containing the appliance or within the vicinity of the appliance.
6720806944-02.1Wo
4
10mm
350m
m
5
m
m
5
m
m
6
0
0
mm
*
*
93
0m
m
2
0
mm
*

20
Maintaining your appliance
Greenstar i System ErP – 6 720 806 947 (2015/03)
6 Maintaining your appliance
Your new gas-fired appliance represents a long term investment in a reliable, high quality product.
Wipe the appliance casing with a soft clean cloth. Please do not use chemical cleaning products which may damage the paint finish.
In order to realise its maximum working life, and to ensure it continues to operate at peak efficiency and performance, it is essential
that your appliance receives regular servicing and maintenance checks from a competent person beyond the initial guarantee
period.
If your Greenstar gas-fired appliance should fail to operate correctly or requires servicing, please contact the Worcester, Bosch
Group Appointments Team (see rear cover for details).
Details of the appliance including the Gas Council number can be found on the front cover of these User Instructions and on the
appliance identification label on the appliance facia.
The Gas Council number is also listed on the front cover of your Installation, Commissioning and Servicing Instructions.
7Faultfinding
In the event that the appliance stops functioning or does not perform as expected, you can carry out a few simple checks. These
checks are some of the most common causes and are listed in the table below. Should the problem persist or if otherfault codes are
displayed, then it will be necessary to contact Worcester, Bosch Group.