Bosch Worcester 2000 GC2000iW C Series User manual

6 721 814 552 (2019/09) UK/IE
User Instructions
Gas-fired condensing combi appliance
Worcester 2000
2
13
40
bar
GC2000iW C

Preface
Worcester 2000 – 6 721 814 552 (2019/09)
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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Worcester 2000 – 6 721 814 552 (2019/09)
Table of contents 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
minimising danger are not taken.
The following signal words are defined 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 Explanation of symbols and safety instructions . . . . . . . . . . . 3
1.1 Explanation of symbols . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 General safety instructions . . . . . . . . . . . . . . . . . . . . . . . 4
2 Product Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1 Appliance identification and serial number . . . . . . . . . . 5
2.2 Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.3 Maintaining your appliance . . . . . . . . . . . . . . . . . . . . . . . 6
2.4 Benchmark standard . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
3 Prepare for operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1 Sealed heating system . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1.1 Checking the system pressure. . . . . . . . . . . . . . . . . . . . . 6
3.1.2 Constantly re-pressuring the system pressure . . . . . . . . 6
3.2 Topping up the system pressure . . . . . . . . . . . . . . . . . . . 7
4 Operating the appliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.1 Switching on/off the appliance . . . . . . . . . . . . . . . . . . . . 8
4.2 Control panel overview. . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.3 Screen display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
4.4 Setting the flow temperature . . . . . . . . . . . . . . . . . . . . . . 9
4.5 Setting the DHW heating . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.5.1 Set DHW temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.5.2 Setting comfort mode or ECO mode . . . . . . . . . . . . . . . . 9
4.6 Setting summer mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5 Key (accessories) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
5.1 Key LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
6 Shutdown. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
6.1 Setting frost protection . . . . . . . . . . . . . . . . . . . . . . . . .10
7 Clearances and ventilation information . . . . . . . . . . . . . . . . .10
7.1 Appliance clearances . . . . . . . . . . . . . . . . . . . . . . . . . . .10
7.2 Ventilation information. . . . . . . . . . . . . . . . . . . . . . . . . .11
8 Malfunction or failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
8.1 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
8.2 Extreme cold weather. . . . . . . . . . . . . . . . . . . . . . . . . . .12
9 Environmental protection/disposal. . . . . . . . . . . . . . . . . . . . .12
10 Tips on energy saving. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
11 Your guarantee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
12 Energy consumption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
12.1 Product data on energy consumption . . . . . . . . . . . . . .14
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
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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.
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 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 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.

Product Information
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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.
2 Product Information
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.
▶ The appliance must be serviced annually by a competent, qualified
person, such as a Worcester service engineer, British Gas engineer or
other Gas Safe registered engineer.
▶ 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.
▶ Always use original spares, to help maintain the efficiency, safety and
reliability of the appliance.
Model:
Serial number:
Date of installation:
##########-001
1

Prepare for operation
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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.
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 gauge reads less than 1 bar.
▶ If a permanent significant decrease or increase in pressure is
indicated on the pressure gauge, contact your installer or
maintenance engineer.
3.1.1 Checking the system pressure
Your installer will advise you of the optimum operating pressure.
▶ Check the system pressure from 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 Constantly re-pressuring the system pressure
Constantly having to re-pressuring the heating system should be
investigated as the concentration of inhibitor protection in the system
will be reduced; this can result in corrosion within the heating system
reducing the efficiency and increasing contaminates.
▶ Check for leaks on heating system (pipe work and radiator valves).
▶ Contact your installer or maintenance engineer if a recurring
significant decrease or increase in pressure is indicated on the
pressure screen.
0010015027-002
1
2
Min
Max

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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 3.
▶ 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.
▶ Monitor the pressure gauge.
– 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.
– 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.
▶ Set the pressure between 1 and 1.5 bar pressure.
▶ 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.
Once the pressure has settled between 1 and 1.5 bar.
▶ Ensure the valves are closed.
▶ Remove the hose [2] and replace the blanking cap [1].
Fig. 3 External filling loop
If the pressure gauge reads more than 1.5 bar as a result of over filling:
▶ Bleed one radiator until the pressure gauge returns to between 1 and
1.5 bar.
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.
– Pull the lever [1] down to start the filling process.
– The needle on the pressure gauge will start to rise.
▶ When the pressure, shown on the pressure gauge, reaches between
the 1 and 1.5 bar [2],
– Release the lever [1] to stop the filling process.
▶ Top up the system pressure, if as a result of the air bleeding the
pressure drops off.
Fig. 4
If the pressure gauge reads more than 1.5 bar as a result of over filling:
▶ Bleed one radiator until the pressure gauge returns to between 1 and
1.5 bar.
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

Operating the appliance
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4 Operating the appliance
These operating instructions describe the operation of the gas-fired
condensing boiler. Depending on which user interface is used the
operation of several functions may not correspond to this description.
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 in the device.
Switching off
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,
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 function is not active when 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.
4.2 Control panel overview
Fig. 5
[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
0010029487-001
1
2 3 4 5 6 7 8 9

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4.3 Screen display
Fig. 6 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.
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.
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 in the operating instructions for the heating
control.
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
0010016015-003
10 9
21 3 4 5 6
8 7

Key (accessories)
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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 [1] on the Key displays different states with flashing or constant
colours.
Table 4 LED status
For more information please refer to your control manual.
6 Shutdown
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.
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.
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. 7 Appliance minimum clearances
Table 5 Appliance minimum clearances
Description of the LED displays Example
Flashing red:
Fault, e.g. no communication between the Key and
appliance:
▶ Install the key again, 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.
Minimum clearances
Description Dimensions (mm)
X Appliance width 400
Y Appliance height 724
Z Appliance depth 300
Maintenance
1 Overall clearance height 1115/1155 1)
1) Height for either 60/100 flue or 80/125 flue
2 Overall clearance depth 900
3 In front of appliance 600
4 Overall clearance width 410
5 Above the appliance 191/231 1)
6 Either side of appliance 5
7 Below the appliance 200
8 Compartment depth 320 2)
2) Clearnace to a combustible material
9 Appliance to removable door 20 2)
0010012940-001

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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.
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 - 1.5 bar?
• Do you have gas?
– 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.
• 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. 8 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/disposal
Worcester 2000 – 6 721 814 552 (2019/09)
12
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/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.
Allofourpackaging materialsare environmentallycompatibleand can be
recycled.
Used appliances
Used appliances contain valuable materials that can be recycled.
Thevariousassemblies can be easilydismantled.Synthetic materialsare
marked accordingly. Assemblies can therefore be sorted by composition
and passed on for recycling or disposal.
Old electrical and electronic appliances
This symbol indicates that the product must not be
disposed of with other waste, but be taken to the waste
collection centers for treatment, collection, recycling and
disposal procedure.
The symbol applies to countries with electronic waste
regulations, for example the European Waste Electrical and Electronic
Equipment Directive 2012/19/EU. These regulations determine the
framework for the return and recycling of used electronic appliances as
applicable within each country.
As electronic equipment 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 your
electronic waste will help to conserve natural resources.
For additional information on the environmentally safe disposal of
electrical and electronic equipment, please contact the relevant local
authorities, your household waste disposal service or the retailer where
you purchased the product.
For additional information, please visit:
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
13
Worcester 2000 – 6 721 814 552 (2019/09)
10 Tips on energy saving
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 73 °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.
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
Comfort+ II RF registration
▶ Please note that your Comfort+ II RF guarantee will need separate
registration.

Energy consumption
Worcester 2000 – 6 721 814 552 (2019/09)
14
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.
Table 7 Product data on energy consumption Worcester 2000
Product data Symbol Unit 7 736 902 027 7 736 902 028
Product type – – GC2000iW 25 C GC2000iW 30 C
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 1) 4% 87.7 87.7
At 30 % of rated heat output and low temperature regime 2) 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 39 39
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 – –

Bosch Thermotechnology Ltd.
Cotswold Way, Warndon
Worcester WR4 9SW
United Kingdom
Tel. [phone]
worcester-bosch.co.uk
TECHNICAL SUPPORT: 0330 123 3366
RENEWABLE SUPPORT: 0330 123 9229
CONTROLS AND CONNECTIVITY TEAM: 0330 123 3641
APPOINTMENTS: 0330 123 9339
SPARES: 0330 123 9779
LITERATURE: 0330 123 9119
TRAINING: 0330 123 0166
SALES: 0330 123 9669