Worcester Greenstar 2000 User manual

6 721 820 553 (2021/02) UK/IE
User Instructions
Gas-fired condensing combi appliance
Greenstar 2000
2
13
40
bar
GR2300iW C

Preface
Greenstar 2000 – 6 721 820 553 (2021/02)
2
Preface
Dedicated to heating comfort.
Thank you for purchasing a Worcester product. We pride ourselves on
manufacturing appliances to the strictest quality control standards
throughout every stage of production.
Worcester, Bosch group has led the field in innovative product design
and performance for over 50 years. This heritage means all our products
are of exceptional quality and proven reliability.
Our products employ the latest technologies and they are reliable,
extremely energy efficient, offering you economical running costs and
value for money. They are amongst the top energy rated appliances
available.
There is also the reassurance of our parts and labour guarantee. Our
Customer Service team is here to help you get the best from your
Worcester product throughout its lifetime. Whatever your enquiry, our
specially trained team is available at our Worcester based contact centre
and online via the website. For contact details see the back cover.

Table of contents
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Greenstar 2000 – 6 721 820 553 (2021/02)
Table of contents
1 Explanation of symbols and safety instructions . . . . . . . . . . . 4
1.1 Explanation of symbols . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2 General safety instructions . . . . . . . . . . . . . . . . . . . . . . . 4
2 Product Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1 Appliance identification and serial number . . . . . . . . . . 6
2.2 Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.3 Maintaining your appliance . . . . . . . . . . . . . . . . . . . . . . . 6
2.4 Benchmark standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3 Prepare for operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.1 Sealed heating system . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.1.1 Checking the system pressure. . . . . . . . . . . . . . . . . . . . . 7
3.1.2 Low pressure indication . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.1.3 Constantly re-pressurising the system . . . . . . . . . . . . . . 7
3.2 Topping up the system pressure . . . . . . . . . . . . . . . . . . . 8
4 Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.1 Switching on/off the appliance . . . . . . . . . . . . . . . . . . . . 9
4.2 Control panel overview . . . . . . . . . . . . . . . . . . . . . . . . .10
4.3 Screen display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
4.4 Setting the flow temperature. . . . . . . . . . . . . . . . . . . . .11
4.5 Setting the DHW heating . . . . . . . . . . . . . . . . . . . . . . . .11
4.5.1 Set DHW temperature . . . . . . . . . . . . . . . . . . . . . . . . . .11
4.5.2 Setting comfort mode or ECO mode . . . . . . . . . . . . . . .11
4.6 Setting summer mode . . . . . . . . . . . . . . . . . . . . . . . . . .11
4.7 Manual mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
5 Key (accessories) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
5.1 Key LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
6 Shutdown. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
6.1 Setting frost protection . . . . . . . . . . . . . . . . . . . . . . . . .12
7 Clearances and ventilation information . . . . . . . . . . . . . . . . .13
7.1 Appliance clearances . . . . . . . . . . . . . . . . . . . . . . . . . . .13
7.2 Ventilation information. . . . . . . . . . . . . . . . . . . . . . . . . .14
8 Malfunction or failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
8.1 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
8.2 Extreme cold weather . . . . . . . . . . . . . . . . . . . . . . . . . .16
9 Environmental protection and disposal . . . . . . . . . . . . . . . . .16
10 Tips on energy saving. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
11 Your guarantee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
12 Energy consumption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
12.1 Product data on energy consumption . . . . . . . . . . . . . .19
13 Data Protection Notice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

Explanation of symbols and safety instructions
Greenstar 2000 – 6 721 820 553 (2021/02)
4
1 Explanation of symbols and safety instructions
1.1 Explanation of symbols
Warnings
In warnings, signal words at the beginning of a warning are used to
indicate the type and seriousness of the ensuing risk if measures for
minimizing danger are not taken.
The following signal words aredefined and can be used in this document:
DANGER
DANGER indicates that severe or life-threatening personal injury will
occur.
WARNING
WARNING indicates that severe to life-threatening personal injury may
occur.
CAUTION
CAUTION indicates that minor to medium personal injury may occur.
NOTICE
NOTICE indicates that material damage may occur.
Important information
The info symbol indicates important information where there is no risk to
people or property.
Additional symbols
Table 1
1.2 General safety instructions
HNotices for the target group
These operating instructions are intended for the
heating system operator.
All instructions must be observed. Failure to comply
with instructions may result in material damage and
personal injury, including danger to life.
▶ Read and retain the operating instructions (heat
source, heating controller, etc.) prior to operation.
▶ Observe the safety instructions and warnings.
HDetermined use
The product may only be used for the heating of boiler
water and for DHW heating.
Any other use is considered inappropriate. We assume
no liability for damage occurring due to non-permitted
use.
HIf 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.
▶ Move 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.
HDanger to life from poisoning by flue gas
There is a danger to life from escaping flue gas.
▶Never modify any parts through which flue gas is
routed.
If flues are damaged or leaking, or if you smell flue gas,
observe the following rules.
▶ Switch off the heat source.
▶ Open doors and windows
▶ Warn your neighbours and leave the building
immediately.
▶ Prevent third parties from entering the building.
▶ Notify an approved contractor.
▶ Have any defects rectified.
Symbol Meaning
▶ a step in an action sequence
a reference to a related part in the document
• a list entry
–a list entry (second level)

Explanation of symbols and safety instructions
5
Greenstar 2000 – 6 721 820 553 (2021/02)
HDanger to life from carbon monoxide
Carbon monoxide (CO) is a poisonous gas, which
arises during the incomplete combustion of fossil fuels
such as oil, gas or solid fuels.
Dangers arise, if carbon monoxide escapes from the
heating system due to a fault or a leak and collects
unnoticed in enclosed spaces.
You can neither see, taste nor smell carbon monoxide.
To avoid danger from carbon monoxide:
▶ Have the heating system inspected and serviced
regularly by an approved contractor.
▶ Use a CO detector, which gives an alarm in good
time if CO escapes.
▶ If you suspect a CO leak:
– Warn your neighbours and leave the building
immediately.
– Call an approved contractor.
– Have any defects rectified.
HInspection, cleaning and maintenance
The user is responsible for ensuring the heating
system is safe and environmentally compatible.
Non-existent or improper inspection, cleaning and
maintenance may result in personal injury, including
danger to life or material damage.
We recommend that you enter into a contract covering
an annual inspection and responsive cleaning and
maintenance with an approved contractor.
▶ Have work carried out only by an approved
contractor.
▶ Have the appliance and heating system inspected
by an approved contractor at least once a year.
▶ Have any required cleaning or maintenance work
carried out immediately.
▶ Have any defects in the appliance and heating
system remedied immediately, independent of the
annual inspection.
HFittings and modification
Only a competent engineer can remove the appliance
case and carry out any work, in accordance with the
relevant Installation Regulations.
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.
HCombustion air/ambient air
The air in the installation location must be free of
flammable or chemically aggressive substances.
▶ Do not store or use any flammable or explosive
materials (paper, petrol, thinners, paints, etc.) in
the vicinity of the heat source.
▶ Do not store or use any corrosive substances
(solvents, adhesives, chlorinated cleaning agents,
etc.) in the vicinity of the heat source.
HGeneral considerations
▶ The boiler must be installed in a well ventilated area.
The openings must be kept in good condition.
▶ The vents or any other component contributing to
the functioning of the boiler must not be reduced or
sealed.
▶ We recommend an annual service of the appliance
by an approved engineer to ensure reliable and
efficient operation.
HSafety of electrical devices for domestic use
and similar purposes
The following requirements apply in accordance with
EN 60335-1 in order to prevent hazards from
occurring when using electrical appliances:
“This appliance can be used by children of 8 years and
older, as well as by people with reduced physical,
sensory or mental capabilities or lacking in experience
and knowledge, if they are supervised and have been
given instruction in the safe use of the appliance and
understand the resulting dangers. Children shall not
play with the appliance. Cleaning and user
maintenance must not be performed by children
without supervision.”
“If the power cable is damaged, it must be replaced by
the manufacturer, its customer service department or
a similarly qualified person, so that risks are avoided.”
HPlease read these instructions carefully
▶ These instructions are applicable to the Worcester
appliance model/s stated on the front cover only.
▶ These instructions apply in the UK/IE only and must
be followed except for any statutory obligation.

Product Information
Greenstar 2000 – 6 721 820 553 (2021/02)
6
2ProductInformation
2.1 Appliance identification and serial number
Fig. 1 Position of data label
The data label [1] contains information of the appliance model and serial
number. This is located centrally on the bottom of the appliance in line
with the control panel.
For your own records
Please ensure that the Commissioning Checklist has been completed by
your installer or service engineer.
Table 2 Appliance details
The appliance model and serial number can be found on the appliance
data label.
2.2 Servicing
Ensure that the service engineer completes the Service Record in the
Benchmark Checklist after each service.
The Service Record can be found at the rear of the appliance’s
Installation and Maintenance Instructions. It will be required in the event
of any guarantee work and may be required by the local Building Control
Inspector.
▶ To ensure the continued safe, reliable and environmentally optimum
operation of the boiler, it must be thoroughly serviced annually by a
competent, qualified person, such as a Worcester service engineer,
British Gas engineer or other Gas Safe registered engineer. In the
Republic of Ireland servicing work must be carried out by a Worcester
service engineer or other Registered Gas Installer (RGII).
– Having a contract covering annual servicing, cleaning and
maintenance is a good way to ensure this is not missed.
– It is important that any required maintenance or repairs are
carried out without delay.
▶ Ensure that the service engineer completes the Service Record, at
the rear of the Installation and Maintenance Instructions manual,
after each service.
▶ Have any work carried out by a competent, qualified person,
Worcester service engineer, British Gas engineer or other Gas Safe
registered engineer. In the Republic of Ireland servicing work must be
carried out by a Worcester service engineer or other Registered Gas
Installer (RGII).
▶ Always use original spares, to help maintain the efficiency, safety and
reliability of the appliance.
2.3 Maintaining your appliance
Your new 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 the appliance’s maximum working life, and to ensure
the appliance continues to operate at peak efficiency and performance,
it is essential that servicing and maintenance checks are performed at
least once a year by a competent engineer in accordance with the current
Gas Safe Regulations.
If you would like to know more about servicing options from Worcester,
Bosch Group, please visit worcester-bosch.co.uk.
Please tick the appropriate box on your warranty registration card for
further details of the Worcester, Bosch Group Service Contract.
When your appliance requires servicing please contact a Worcester,
Bosch Group contact centre (see rear cover, appointments).
In addition to the service contract we are pleased to offer a one-off
annual service or breakdown call out for your appliance.
Maintenance tips
• Appliances on a sealed heating system:
– Regularly check the system pressure.
• Do not obstruct the flue outlet or the air inlet.
• Use in hard water areas:
– In exceptionally hard water areas a device to prevent scale
formation may be fitted. Installation of a salt based water softener
should be in accordance with the requirements of the local water
company. A bypass valve must be fitted and used to fill/top up the
heating system with untreated water.
Important note:
▶ If you have to add water regularly in your heating system, call a
competent, qualified person.
2.4 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.
Model:
Serial number:
Date of installation:
##########-001
1

Prepare for operation
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Greenstar 2000 – 6 721 820 553 (2021/02)
3 Prepare for operation
3.1 Sealed heating system
Appliances that can be connected to sealed heating systems are pre-
pressurised before operation, this pressure must be maintained for safe
use of the appliance.
▶ Check regularly that the pressure is maintained.
▶ Re-charge the system if the pressure indicator reads less than 0.8
bar.
▶ If a permanent significant decrease or increase in pressure is shown
on the pressure indicator, contact your installer or maintenance
engineer.
Pressure indicator
▶ Type of pressure indicator for the system pressure.
– Pressure gauge (an analogue dial showing the pressure)
– Pressure menu (a digital readout of the pressure)
▶ Your appliance may have one or both types of methods to indicate the
system pressure. The type of method used on this appliance will be
detailed in the following section.
3.1.1 Checking the system pressure
Your installer will advise you of the optimum operating pressure.
▶ Check the system pressure on the pressure gauge.
–Static pressure is when appliance is cold and has not fired for
heating or hot water. This will generally be 1 - 1.5 bar.
–Operating pressure is when the appliance is firing for a heating
or hot water demand. This will generally be 1 - 2 bar.
▶ Top up the heating water, if the pressure is too low.
Fig. 2 Pressure gauge for checking the operating pressure
[1] Static pressure range
[2] Operating pressure range
3.1.2 Low pressure indication
Low pressure (shaded area [A]) will be indicated on the appliance:
• The needle is within the area between 0 and 1bar.
Fig. 3 Low pressure indication
[A] Low pressure area
3.1.3 Constantly re-pressurising the system
Constantly having to re-pressurise the heating system should be
investigated as it is an indicator of potential leaks and the concentration
of inhibitor protection in the system will be reduced; this can result in
corrosion within the heating system, reducing efficiency and increasing
contaminates.
▶ Check for leaks on heating system (pipework and radiator valves).
▶ Contact your installer or maintenance engineer if a recurring
significant decrease or increase in pressure is indicated on the
pressure screen.
System pressure increasing:
▶ If the system pressure repeatedly increases and you need to vent air
from the radiators, refer to section 3.2 "Topping up the system
pressure", page 8.
0010015027-002
1
2
Min
Max
0010033761-001
Min
A
Max

Prepare for operation
Greenstar 2000 – 6 721 820 553 (2021/02)
8
3.2 Topping up the system pressure
Your installer should have informed you where to find the filling system
and instructed you in its use.
NOTICE
System fill method
▶ You must disconnect the external filling loop after re-pressurisation,
to comply with the Water Authority regulations.
External filling loop
Once the external filling loop and pressure gauge has been located,
follow the instructions for re-pressurising the system.
Refer to figure 4.
▶ Unscrew the blanking cap [1].
▶ Attach the hose [2] to the valve.
– Usually one end of the hose is already connected to one of the
system fill isolation valves.
▶ Ensure both ends [3] of the hose are screwed on hand tight.
– The system fill isolation valves [4] are in a closed position (the
handle/screwdriver slot is across the valve).
▶ Turn the handle/screwdriver slot through 90° to open valves and
slowly fill the system to between 1 and 1.5bar.
– The system fill isolation valves [5] are opened (the handle/
screwdriver slot is in-line with the valve).
– The needle on the pressure gauge will start to rise.
▶ Turn the handles/screwdriver slots back, through 90°, to close the
valves.
– The system fill isolation valves [6] are in a closed position (the
handle/screwdriver slot is across the valve).
▶ Top up the system pressure, if as a result of the air bleeding the
pressure drops off.
▶ Remove the hose [2] and replace the blanking cap [1].
Fig. 4 External filling loop
Keyless filling link
Locate the filling link (underneath the appliance on the right hand side)
and follow the instructions for re-pressurising the system.
Re-pressurise the system.
▶ To start the filling process, pull the lever [1] down.
– The needle on the pressure gauge will start to rise.
▶ To stop the filling process, release the lever [1] when:
– The pressure, shown on thepressure gauge, reaches between the
1 and 1.5 bar [2].
▶ Top up the system pressure, if as a result of the air bleeding, the
pressure drops off.
Fig. 5 Keyless filling link
If the pressure gauge reads more than 1.7 bar as a result of over filling:
▶ Bleed one radiator until the pressure gauge returns to between 1 and
1.7 bar.
▶ It is good practice to bleed any excess air that has entered the heating
system due to pressure loss. Locate and open the radiator's bleed/
vent point, closing the valve when water begins to flow.
▶ If, through normal boiler operation, the PRV pipe starts to leak, it
could be a sign of system pressure being too high. In this instance
please bleed a radiator as described above.
WARNING
Risk of damage to the system from corrosion!
If the pressure in your heating system is repeatedly rising and you are
repeatedly venting radiators, this can indicate that there is corrosion
occurring within the heating system.
To prevent serious damage to the entire system:
▶ Contact a heating engineer.
Failure toproperly maintain the heating system may affect your warranty.
System pressurecan be checked viathe boiler’s pressure gauge/reading
when the system is cold, ensuring the reading is in the green zone at all
time.
0010015034-001
1
2
3
4
5
6
Min
1 bar
1.5 bar
Max
0010015050-001
11
Min
1 bar
1.5 bar
Max
2

Operation
9
Greenstar 2000 – 6 721 820 553 (2021/02)
CAUTION
Caution must be exercised when venting radiators or re-pressurising/
topping up the heating system:
▶ Do not vent air from radiators whilst the central heating is switched
on.
▶ Allow 30 minutes after venting the radiators before using central
heating or hot water.
▶ Whilst venting radiators, do not allow the pressure to drop below the
green zone on the boiler’s pressure gauge/reading.
If symptoms persist:
▶ Do not repeatedly vent your radiators.
▶ Contact a heating engineer.
4Operation
These operating instructions describe the operation of the gas-fired
condensing boiler. Therefore please also observe the operating
instructions for the user interface.
4.1 Switching on/off the appliance
Switching on
After initial power-up of the appliance, the appliance will initiate siphon
fill mode.
When and the flow temperature appear alternately on the display,
the appliance remains at minimum heat output for 15 minutes to fill the
condensate trap.
Switching off
NOTICE
Risk of damage to the system from frost!
The heating system can freeze after a prolonged period (e.g. during a
power failure, switching off the power supply, faulty fuel supply,
appliance fault etc.).
▶ Ensure that the heating system is in constant use (particularly when
there is a risk of frost).
Frost protection for the heating system is only ensured if the heating
pump is operational and is pumping heating water through the entire
system.
▶ Leave the heating switched on.
▶ Set the time control to constant ON and set the room thermostat to
12 °C.
The anti-seizing functionis not activewhen the appliance is switched off.
The anti-seizing function prevents the heating pump and the diverter
valve from seizing up following long periods of inactivity.

Operation
Greenstar 2000 – 6 721 820 553 (2021/02)
10
4.2 Control panel overview
Fig. 6
[1] Display
[2] (key: Heating mode on/off, set the maximum flow temperature
[3] *key: Hot water mode, adjusting the hot water temperature
[4] eco key: Toggle economy mode (pre-heat off)
[5] ok key: Save settings
[6] "key: Return/back
[7] key: To navigate through menus and decrease settings
[8] key: To navigate through menus and increase settings
[9] Pressure gauge
4.3 Screen display
Fig. 7 Screen display
Table 3
The heating and hot water system has been set up by the installer to its
optimum settings.
▶ It is advised to make a note of these settings before adjusting so that
you can return to these optimum settings in the future.
0010029487-001
1
2 3 4 5 6 7 8 9
Key Explanation
[1] Digital display
• Displays a temperature or appliance status/diagnostic code.
[2] Central heating (CH)
•( Heating mode On
•] Heating mode Off
[3] Fault indicator
• Displays during a fault condition.
[4] Burner operation
• Displays when the appliance is firing during a CH/DHW
mode.
[5] Internet connected (accessory)
• Displays when compatible controller is connected to the
appliance (not used).
[6] Radio link connected (accessory)
• Displays when compatible controller is connected to the
appliance.
[7] Chimney sweep mode
• Displays during service when the appliance is set to
maximum or minimum output.
[8] Service mode
• Displays when a qualified service engineer is in the service
menus.
[9] Eco mode active
• Displays when in Economy mode (DHW Pre-heat/comfort
function is turned off)
[10] Domestic hot water (DHW)
•* Hot water mode On
•[ Hot water mode Off
0010016015-004
10 9
21 3 4 5 6
8 7

Operation
11
Greenstar 2000 – 6 721 820 553 (2021/02)
4.4 Setting the flow temperature
The maximum flow temperature can be adjusted between 30 °C
and 82 °C. The current flow temperature is shown on the display.
▶ Press the (key.
The set maximum flow temperature is displayed.
▶ Press arrow key or to set the required maximum flow
temperature.
▶ Press the OK key to save. Otherwise the setting will be saved
automatically after 3 seconds.
The display shows the current flow temperature.
The (symbol flashes in the display in heating mode. The Bsymbol
also appears if the burner is active.
WARNING
Risk of scalding!
▶ This appliance is supplied with the CH control set at approximately
65 °C, a temperature that should be suitable for most installations
that comply with the current building regulations. When the boiler
switches from CH to DHW, the temperature of the hot water may
briefly exceed the DHW set point if the CH temperature is set higher
than the DHW temperature. If the CH temperature is changed to
above 65 °C, it is advisable to fit a thermostatic mixing valve (TMV) at
the point of use (e.g. before the bath hot tap or shower) to protect
vulnerable people from scalding.
4.5 Setting the DHW heating
4.5.1 Set DHW temperature
DHW temperature:
▶ Press the *key.
The set DHW temperature is displayed.
▶ Press arrow key or to set the required DHW temperature
▶ Press the OK key to save. Otherwise the setting will be saved
automatically after 3 seconds.
The display shows the current flow temperature.
The *symbol flashes in the display in DHW mode. The Bsymbol also
appears if the burner is active.
4.5.2 Setting comfort mode or ECO mode
In comfort mode, the appliance is continually maintained at the set
temperature. This means there will be a shorter delay when drawing
DHW. However, the device will switch on even if no DHW is being drawn.
In ECO mode, heating-up to the set temperature begins as soon as the
DHW is being drawn.
In ECO mode, to reduce water usage:
▶ Briefly open and close the DHW tap.
The water is heated once to the set temperature.
▶ To set ECO mode: press eco until eco appears in the display.
▶ To return to comfort mode: press the eco key until eco vanishes from
the display.
4.6 Setting summer mode
The heating pump and consequently the heating are switched off in
summer mode. The DHW supply and also the power supply for heating
controls and timer remain active.
NOTICE
Risk of the system freezing.
Frost protection is not available in summer mode.
▶ If there is a risk of frost, exit summer mode (Chapter 6.1).
To activate summer mode:
▶ Press the (key.
▶ Keep pressing the arrow key until appears in the display.
▶ Press the OK key to save. Otherwise the setting will be saved
automatically after 3 seconds.
]is permanently displayed.
Further notices can be found inthe operating instructions for the heating
control.
4.7 Manual mode
Manual mode can be enabled to operate the boiler independent of
controls, should there be a technical issue with time and temperature
controls fitted.
To activate manual mode:
▶ Press and hold the (key for 5 seconds.
▶ Check the flow temperature shown and adjust if necessary.
– The flow temperature will be shown in between two hyphens,
indicating manual mode.
Fig. 8 Manual mode shown on display
Manual mode should be used for a limited time only until the time and
temperature controls are fixed.
▶ To disable Manual Mode press and hold the (key for 5 seconds.
0010034240-001

Key (accessories)
Greenstar 2000 – 6 721 820 553 (2021/02)
12
5 Key (accessories)
5.1 Key LED
Key accessory location
▶ The Key can be located underneath the appliance on the right hand
side.
Key LED status
The LED on the Key displays different states with flashing or constant
colours.
Table 4 LED status
For more information please refer to your control manual.
6Shutdown
6.1 Setting frost protection
NOTICE
Risk of damage to the system from frost!
The heating system can freeze up after a prolonged period (e.g. during a
power failure, switching off the power supply, faulty fuel supply, boiler
fault etc.).
▶ Ensure that the heating system is in constant use (particularly when
there is a risk of frost).
If you are leaving your property unoccupied during cold weather, please
leave your external programmer on constant and your room thermostat
set to 12 °C.
Description of the LED displays Example
Flashing red:
Fault, e.g. no communication between the Key and
appliance:
▶ Install the Keyagain, restore the last functioning status.
Flashing yellow:
No fault, user please wait.
Flashing green:
No fault, initialisation process is running.
Constant red:
Temporary fault:
▶ Wait for normal operating condition to be resumed.
Constant yellow:
▶ Keys with touch-sensitive indicator: Press touch-
sensitive indicator on Key to start pairing.
Constant green:
No fault, normal operating condition.
LED Off:
No fault, power-saving mode or appliance without power.

Clearances and ventilation information
13
Greenstar 2000 – 6 721 820 553 (2021/02)
7 Clearances and ventilation information
7.1 Appliance clearances
Your installer will have provided adequate space around the appliance
for operation, safety and servicing/maintenance access.
• The following detail the necessary clearance around the appliance for
service and maintenance.
WARNING
Risk of injury due to damage to the boiler
▶ Heat-producing kitchen appliances must not be operated directly
underneath the boiler.
CAUTION
Risk of damage to appliance or property
The appliance will overheat if the clearance space around the appliance
is restricted by objects.
▶ Do not restrict this space with the addition of cupboards, shelves etc.
next to or around the appliance.
▶ Do not store any combustible materials on or next to the appliance,
such as clothes, towels, paper or plastic bags.
Fig. 9 Appliance minimum clearances
Table 5 Appliance minimum clearances
Reduced front maintenance minimum clearances
The front servicing clearance for this appliance can be reduced to
450mm.
For installations with a front servicing clearance less than 600mm
(minimum of 450mm), the following additional criteria must be
achieved.
• The bottom of the appliance case must be between 1000mm and
1500mm from the floor.
• There must be at least 450mm clearance in front of the appliance to
floor level. Anything sited below the appliance must not protrude into
this clear space.
• There must be at least 200mm clearance to any structure which is
sited below the appliance.
• There must be at least 300mm clear space to either the left hand or
right hand side of the appliance. This clear space must be from the
required clear height above the appliance to floor level.
– This clearance will not apply if the appliance is sited within
300mm of a door way and the door frame is the only obstruction.
Minimum clearances must be observed to any obstruction/ surface,
(dark shaded areas, figures 10 and 11).
0010012940-001
Minimum clearances
Description Dimensions (mm)
X Appliance width 400
YAppliance height 724 1)
1) Side panel height = 710mm.
Z Appliance depth 300
Maintenance
1Overall clearance height 1094/1134 2)
2) Height for either 60/100 flue or 80/125 flue.
2 Overall clearance depth 900 3)
3) This can be reduced (refer to Reduced front maintenance minimum clearances).
3In front of appliance 600 3)
4 Overall clearance width 410
5Above the appliance 170/210 2)
6Either side of appliance 5
7Below the appliance 200
8Compartment depth 320 4)
4) Clearance to a combustible material.
9Appliance to removable door 20

Clearances and ventilation information
Greenstar 2000 – 6 721 820 553 (2021/02)
14
Fig. 10 Reduced front maintenance clearances - Side view
[A] Appliance.
[1] Above appliance - Same clearance required as for standard
clearances of 60/100 flue or 80/125mm flue.
[2] In front of appliance - Minimum 450mm.
[3] Bottom of appliance to the floor - 1,000 - 1,500mm.
[4] Below appliance - 200mm
Fig. 11 Reduced front maintenance clearances - Front view
[A] Appliance.
[1] Above appliance - Same clearance required as for standard
clearances of 60/100 flue or 80/125mm flue.
[3] Bottom of appliance to the floor - 1,000 - 1,500mm.
[4] Below appliance - 200mm
[5] One side of appliance - Minimum 300mm.
[6] One side of appliance - Minimum 5mm.
7.2 Ventilation information
The air supply must not be restricted or contaminated.
Ventilation considerations
▶ Do not place objects to hinder the air circulation required by the
appliance.
▶ The installation premises may require ventilation to be fitted
according to its features or use.
0010031674-001
1
2
2
4
3
A
0010031673-001
16
5
5
4
3
A

Malfunction or failure
15
Greenstar 2000 – 6 721 820 553 (2021/02)
8 Malfunction or failure
If you believe there is a problem with your central heating or hot water
supply, before you contact your installer/maintenance engineer and
report the error and appliance type carry out the following checks.
Basic checks
Some items to check before placing a call are:
• Is the electrical power switched on to the appliance?
• Is the programmer/timer set to ON or in an ON period?
• Is the room thermostat set too low?
• Is the cylinder thermostat (if fitted) set too low?
• Is the cold water main turned on?
• Sealed heating system:
– Is the static system pressure (when appliance is cold) between
1 and 1.5 bar?
•Doyouhavegas?
– Are other gas appliances working, gas cooker/hob for example?
– Has your credit run out on your gas pre-payment meter?
Details of your installer should be available in the Commissioning
Checklist or can be recorded in the following section.
Installer/maintenance engineer
Table 6
Worcester, Bosch Group
The appliance is supported in the UK and Eire by Worcester, Bosch
Group.
Specialist service engineers are available to attend an appliance
breakdown.
Invoices for attendance and repair work carried out on this appliance by
any third party will not be accepted.
• No charge will be made for parts and/or labour providing:
– The appliance fault is found and the appliance is within the
guarantee period. Reasonable evidence of this must be supplied
on request. i.e. a completed Commissioning and service record
and has been regularly serviced at least once a year.
• A call-out charge will be made where:
– The appliance is outside the guarantee period or has not been
serviced in accordance with the manufacturers instructions.
– Our Field Service Engineer finds no fault with the appliance.
– The cause of breakdown is misuse or with other parts of your
plumbing/heating system, or with equipment not supplied by
Worcester, Bosch Group.
No appliance fault is found on over 30% of all service calls.
▶ In the case of a suspected fault, refer to the basic checks earlier in this
section.
In the event of an appliance fault or breakdown please contact
Worcester, Bosch Group appointments team on 0330 123 9339. Your
advisor will arrange for an engineer to call with the minimum of delay;
under normal circumstances this will be from 1‒3 working days
(excluding weekends and bank holidays) for priority breakdown
situations (no hot water and/or heating).
8.1 Troubleshooting
The Hsymbol indicates that a fault has occurred. The cause of the fault
is displayed in code (e.g. fault code 214).
Fig. 12 Example of a fault code
Some faults lead to a shutdown of the appliance, which only starts again
after a reset:
▶ Switch off the appliance and switch it on again.
-or-
▶ Press the and arrows simultaneously, until the symbols Hand
!are no longer be displayed.
The appliance starts up again. The flow temperature is displayed.
If a fault can not be eliminated:
▶ Contact a Installer/Service Engineer or Worcester, Bosch Group
appointments team on 0330 123 9339.
▶ You will need to provide them with the displayed fault code and the
following appliance data.
– Appliance type and serial number.
– Commissioning date.
Installer/maintenance engineer details
Engineer name:
Company
name:
Company
address:
Telephone:
Email:
0010016301-001

Environmental protection and disposal
Greenstar 2000 – 6 721 820 553 (2021/02)
16
8.2 Extreme cold weather
In certain instances where the condensate pipe work is run externally or
in an unheated area, such as a garage, the condensate pipe work can be
at risk of freezing, even if well insulated.
A frozen/blocked condensate pipe will cause the boiler to shut down.
Worcester, Bosch Group have available helpful videos on thawing frozen
condensate pipe work on our website in the Customer service section.
WARNING
Falling hazard!
Failure to follow this guidance may result in personal injury.
▶ Only attempt to thaw a condensate pipe that is at ground level and
easily accessible.
▶ Never attempt to thaw a condensate pipe that is at height.
CAUTION
Risk of damage to pipe work!
Thermal shock from boiling water can damage plastic pipes.
▶DO NOT use boiling water to thaw the condensate pipe!
CAUTION
Slip hazard
▶ Ensure that the subsequent freezing of any water does not result in a
slip hazard.
If the condensate pipe has frozen:
▶ Locate the blockage.
– It is likely that the pipe is frozen at the most exposed point outside
the building or where there is an obstruction to flow. This could be
the open end of the pipe, at a bend or elbow, or where there is a
sag in the pipe in which condensate can collect.
– The location of the blockage should be identified as closely as
possible before taking further action.
▶ Thaw the frozen pipe.
– The pipe can be thawed by applying a hot water bottle, a
microwaveable heating pack (the sort used for muscular aches
and pains) or a cloth soaked in hot water to the exterior of the
pipe, close to the point of blockage.
– Hot water, but not boiling, can also be poured onto the pipe from
a watering can or similar container.
– Care must be taken at pedestrian areas where this water may
freeze and create a slip hazard.
▶ Worcester, Bosch Group have available on our website helpful videos
in the Customer service section to aid in thawing a frozen pipe.
▶ Reset the appliance and wait two or three minutes for the appliance
to restart.
▶ Contact Worcester, Bosch Group Appointments Team on:
0330 123 9339, if the boiler does not restart.
▶ Contact your installer in order to find a permanent solution to the
problem.
9 Environmental protection and disposal
Environmental protection is a fundamental corporate strategy of the
Bosch Group.
The quality of our products, their economy and environmental safety are
all of equal importance to us and all environmental protection legislation
and regulations are strictly observed.
We use the best possible technology and materials for protecting the
environment taking account of economic considerations.
Packaging
Where packaging is concerned, we participate in country-specific
recycling processes that ensure optimum recycling.
All of our packaging materialsare environmentally compatible andcan be
recycled.
Used appliances
Used appliances contain valuable materials that can be recycled.
The various assemblies can be easily dismantled. Synthetic materials are
marked accordingly. Assemblies can therefore be sorted by composition
and passed on for recycling or disposal.
Old electrical and electronic appliances
This symbol means that the product must not be disposed
of with other waste, and instead must be taken to the waste
collection points for treatment, collection, recycling and
disposal.
The symbol is valid in countries where waste electrical and
electronic equipment regulations apply, e.g. "European Directive 2012/
19/EC on old electronic and electrical appliances". These regulations
define the framework for the return and recycling of old electronic
appliances that apply in each country.
As electronic devices may contain hazardous substances, it needs to be
recycled responsibly in order to minimize any potential harm to the
environment and human health. Furthermore, recycling of electronic
scrap helps preserve natural resources.
For additional information on the environmentally compatible disposal
of old electrical and electronic appliances, please contact the relevant
local authorities, your household waste disposal service or the retailer
where you purchased the product.
You can find more information here:
www.weee.bosch-thermotechnology.com/
Batteries
Batteries must not be disposed together with your household waste.
Used batteries must be disposed of in local collection systems.

Tips on energy saving
17
Greenstar 2000 – 6 721 820 553 (2021/02)
10 Tips on energy saving
Quick Tap function
▶ Fully open your hot water tap for at least 3 seconds. This ignites the
boiler.
▶ Turn hot water tap to fully closed.
▶ Wait up to 30 seconds1) as the boiler continues to prepare hot water.
▶ Open your hot water tap; hot water is available2)
On average, 3.5 litres of water can be saved when using the Quick Tap
function.
Water saving varies depending on user behaviour, pipework design and
the time of year, for example, if Central Heating is on during the winter,
DHW will heat up quicker than in the summer, reducing the potential for
water saving. Savings are calculated based on average mains water
pressure, a heat-up time of 30 seconds and close proximity of the tap to
the boiler
Heating economically
The appliance provides a high level of comfort whilst keeping fuel
consumption and the environment effects as low as possible.
The appliance is controlled in such a way that it delivers heat at the
correct rate and only if there is a clear demand from the system.
Central heating systems with thermostatic radiator valves
With modern heating systems set around a 20 °C heat loss, the optimum
setting for a condensing boiler will be approximately 65 °C for the central
heating temperature. This is to ensure a return temperature of less than
52 °C.
The system must be balanced correctly and the radiators may need
upgrading. This allows the boiler to condense as much as possible for the
central heating system.
The temperature of each room can be set individually (except primary
room with the room thermostat) using the thermostatic radiator valves.
Room thermostats
Reducing the setting of the room thermostat by 1 °C can reduce fuel
consumption by up to 10%.
New control systems
Upgrade your heating control system if necessary with the latest
equipment available.
Roof insulation
Around 30% of the heat loss from a property is through the roof. Replace
any old insulation with new insulation, preferably of around 200mm
thickness or more.
Window frames
Single glazed windows, particularly those with steel frames, can lose a
great deal of heat. Consideration should be given to replacement with
PVCu or wooden framed double glazed units.
Radiators
If a radiator is sited underneath a window, its performance will be
affected if the curtains are allowed to drape over the radiator. Shelves
fitted above or in front of the radiator should also be avoided.
It is advisable to manually adjust all thermostatic radiator valves every
2‒3 months to prevent them sticking. Ensure radiator valves are
correctly set and not damaged.
Draughts
Try to ensure that draughts around doors, windows, letter boxes and
keyholes etc. are reduced by using a suitable draught excluder.
WARNING
Air vents!
▶ Do not block or seal any air vents that are installed to ensure that the
appliance operates safely.
Curtains
Lined curtains, or heavier full length curtains can provide excellent
insulation. However, always ensure that the curtains do not drape over
radiators.
1) If the hot water reaches the set temperature before 30 seconds has elapsed, the
boiler will stop firing
2) Hot water is available at the boiler. Delivery time to the tap will vary on the
pipework design and tap distance from the boiler

Your guarantee
Greenstar 2000 – 6 721 820 553 (2021/02)
18
11 Your guarantee
This appliance has a guarantee against faulty materials or workmanship
from the date of installation subject to the following terms and
conditions:
• During the period of this guarantee any components of the appliance
that are proven to be faulty or defective in manufacture will be
exchanged or repaired free of charge by Bosch Thermotechnology
Ltd.
• The householder may be asked to prove the date of installation, that
the appliance was correctly commissioned and, where appropriate,
serviced to the satisfaction of Bosch Thermotechnology Ltd. These
should be documented in the commissioning and service records in
the Installation and Maintenance Instructions.
• The appliance has been used only for the normal domestic purposes
for which it was designed.
This guarantee does not affect your statutory rights.
Guarantee registration
Your appliance/product carries a guarantee against faulty material or
manufacture subject to Terms and Conditions.
To read the full Terms & Conditions please visit us on-line at
www.worcester-bosch.co.uk/guarantee.
Your statutory rights are not affected by the manufacturer’s guarantee

Energy consumption
19
Greenstar 2000 – 6 721 820 553 (2021/02)
12 Energy consumption
12.1 Product data on energy consumption
The following product data comply with the requirements of the EU Regulations No. 811/2013, No. 812/2013, No. 813/2013 and No. 814/2013
supplementing the Regulation (EU) 2017/1369.
Natural Gas appliances
Table 7 Product data on energy consumption Greenstar 2000
Product data Symbol Unit 7 736 902 099 7 736 902 100
Product type – – GR2300iW 25 C NG GR2300iW 30 C NG
Condensing boiler – –  
Low temperature boiler – – 
B1 boiler – –  
Cogeneration space heater – – 
Equipped with a supplementary heater? – – – –
Combination heater – – 
Rated heat output Prated kW 20 20
Seasonal space heating energy efficiency s%93 93
Energy Efficiency Class – – A A
Useful heat output
At rated heat output and high temperature regime 1)
1) High-temperature regime means 60 °C return temperature at heater inlet and 80 °C feed temperature at heater outlet.
P4kW 20 20
At 30 % of rated heat output and low temperature regime 2)
2) 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).
P1kW 6.7 6.7
Useful efficiency
At rated heat output and high temperature regime 4% 87.7 87.7
At 30 % of rated heat output and low temperature regime 1%97.9 97.9
Auxiliary electricity consumption
At full load elmax kW 0.0280 0.0280
At part load elmin kW 0.0110 0.0110
In standby mode PSB kW 0.0027 0.0027
Other items
Standby heat loss Pstby kW 0.055 0.055
Ignition burner power consumption Pign kW – –
Emissions of nitrogen oxides (only gas- or oil fired) NOxmg/kWh 35 35
Annual energy consumption QHE kWh 17.222 17.222
Annual energy consumption QHE GJ 62 62
Sound power level, indoors LWA dB 43 43
Additional data for combination heaters
Declared load profile – – XL XL
Water heating energy efficiency wh % 84 84
Water heating energy efficiency class – – A A
Daily electricity consumption (average climate conditions) Qelec kWh 0.12 0.12
Annual electricity consumption AEC kWh 27 26
Daily fuel consumption Qfuel kWh 21.810 22.436
Annual fuel consumption AFC GJ 17 18
Indication about ability working only during off-peak hours – –  
Other load profiles – – – –
Standing loss S W – –
Storage volume V l – –
Non-solar storage volume (Vbu) Vbu l – –

Energy consumption
Greenstar 2000 – 6 721 820 553 (2021/02)
20
Liquid Gas appliances
Table 8 Product data on energy consumption Greenstar 2000
Product data Symbol Unit 7 736 902 101 7 736 902 102
Product type – – GR2300iW 25 C LPG GR2300iW 30 C LPG
Condensing boiler – –  
Low temperature boiler – – 
B1 boiler – –  
Cogeneration space heater – – 
Equipped with a supplementary heater? – – – –
Combination heater – – 
Rated heat output Prated kW 20 20
Seasonal space heating energy efficiency s% 93.0 93.0
Energy Efficiency Class – – A A
Useful heat output
At rated heat output and high temperature regime 1)
1) High-temperature regime means 60 °C return temperature at heater inlet and 80 °C feed temperature at heater outlet.
P4kW 20 20
At 30 % of rated heat output and low temperature regime 2)
2) 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).
P1kW 6.7 6.7
Useful efficiency
At rated heat output and high temperature regime 4% 89.6 89.6
At 30 % of rated heat output and low temperature regime 1%98.8 98.8
Auxiliary electricity consumption
At full load elmax kW 0.0280 0.0280
At part load elmin kW 0.0110 0.0110
In standby mode PSB kW 0.0027 0.0027
Other items
Standby heat loss Pstby kW 0.055 0.055
Ignition burner power consumption Pign kW – –
Emissions of nitrogen oxides (only gas- or oil fired) NOxmg/kWh 66 66
Annual energy consumption QHE kWh 16.944 16.944
Annual energy consumption QHE GJ 62 62
Sound power level, indoors LWA dB 43 43
Additional data for combination heaters
Declared load profile – – XL XL
Water heating energy efficiency wh % 84 84
Water heating energy efficiency class – – A A
Daily electricity consumption (average climate conditions) Qelec kWh 0.13 0.13
Annual electricity consumption AEC kWh 27 26
Daily fuel consumption Qfuel kWh 21.832 22.056
Annual fuel consumption AFC GJ 17 17
Indication about ability working only during off-peak hours – –  
Other load profiles – – – –
Standing loss S W – –
Storage volume V l – –
Non-solar storage volume (Vbu) Vbu l – –