Bosch Worcester Greenstar 27i System Compact User manual

UK/IE
USER INSTRUCTIONS
WALL HUNG RSF GAS FIRED CONDENSING SYSTEM BOILER
Greenstar i System Compact
6720643358-00.1Wo
FOR CENTRAL HEATING SYSTEMS AND INDIRECT MAINS FED DOMESTIC HOT WATER
6 720 807727 (2013/05)
These appliances are for use with :
Natural Gas or L.P.G.
(Cat. II 2H 3P type C13, C33 & C53)
Model GC Number
Natural Gas 27i System Compact 41-406-13
30i System Compact 41-406-15
L.P.G. 27i System Compact 41-406-14
30i System Compact 41-406-16

2
PREFACE
Greenstar i System Compact – 6 720 807 727 (2013/05)
PREFACE
PLEASE READ THESE INSTRUCTIONS CAREFULLY
These instructions are applicable to the Worcester, Bosch Group boiler model stated on the front cover only.
These instructions apply in the UK/IE only and must be followed except for any statutory obligation.
After installation please leave this User instruction Manual, Installation, Commissioning and Servicing Instructions and completed
Benchmark Checklist with the user.
DEDICATED TO HEATING COMFORT
Thank you for purchasing a Greenstar gas-fired condensing system boiler manufactured by Worcester, Bosch Group. The company
prides itself on manufacturing boilers to the strictest quality control standards throughout every stage of production.
Worcester, Bosch group has led the field in innovative boiler design and performance for 50 years. This heritage means all our
products are of exceptional quality and proven reliability.
The Greenstar range in particular is extremely energy efficient, offering you economical running costs and value for money. It sits in
SEDBUK 2005 Band A, and is therefore amongst the top energy rated boilers available.
There is also the reassurance of our no-nonsense 2 years parts and labour guarantee - backed up by Worcester Total Cover, an
optional complete maintenance scheme to keep your boiler operating at peak condition and efficiency.

3
CONTENTS
Greenstar i System Compact – 6 720 807 727 (2013/05)
CONTENTS
1 Symbols and safety precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1 Explanation of symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2 Safety precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3 Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.1 Operating the boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.1.1 Boiler display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.1.2 Setting the boiler flow temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.1.3 Boiler flow function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.1.4 Setting the flow temperature for domestic hot water system . . . . . 10
3.1.5 Domestic hot water pre-heat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.1.6 Domestic hot water eco mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.1.7 Boiler alert state . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.1.8 Boiler reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.1.9 Turning the central heating off during the summer . . . . . . . . . . . . . . 13
3.1.10 Boiler frost protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.1.11 Turn off the Operation/fault diagnostic light (blue) . . . . . . . . . . . . . 13
4 System Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.1 Sealed heating systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.2 External filling loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5 Service Clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
6 Maintaining your Boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
7 Fault Finding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
7.1 Extreme cold weather . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
8 Fault or Breakdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
9 Environment / disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
10 Tips on energy saving . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
11 Your guarantee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
12 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

4
SYMBOLS AND SAFETY PRECAUTIONS
Greenstar i System Compact – 6 720 807 727 (2013/05)
1 SYMBOLS AND SAFETY PRECAUTIONS
1.1 EXPLANATION OF SYMBOLS
WARNING SYMBOLS
Signal words indicate the seriousness of the hazard in terms of the consequences of not following the safety instructions.
•NOTICE indicates possible damage to property or equipment, but where there is no risk of personal injury.
•CAUTION indicates possible personal injury.
•WARNING indicates possible severe personal injury.
IMPORTANT INFORMATION
ADDITIONAL SYMBOLS
Safety instructions in this document are framed and identified by a
warning triangle which is printed on a grey background.
Notes contain important information in cases where there is no risk of
personal injury or material losses and are identified by the symbol shown on the left. They are bordered by
horizontal lines above and below the text.
Symbol Meaning
1. a numbered step in an action sequence
▶ a step in an action sequence
a reference number to identify or refer to a part or item
• a list entry
– a list entry (second level)
Table 1 Symbols
1

5
SYMBOLS AND SAFETY PRECAUTIONS
Greenstar i System Compact – 6 720 807 727 (2013/05)
1.2 SAFETY PRECAUTIONS
IF YOU SMELL GAS
A gas leak could potentially cause an explosion. If you smell gas, observe the following rules.
▶ Prevent flames or sparks:
– Do not smoke, use a lighter or strike matches.
– Do not operate any electrical switches or unplug any equipment.
– Do not use the telephone or ring doorbells.
▶ Turn off the gas at the meter or regulator.
▶ Open windows and doors.
▶ Warn your neighbours and leave the building.
▶ Prevent anyone from entering the building.
▶ Well away from the building: call the National Gas Emergency Service on 0800 111 999.
▶ L.P.G. boilers: Call the supplier’s number on the side of the gas tank.
BOILER OPERATION:
This boiler must only be operated by a responsible adult who has been instructed in, understands and is aware of the boiler's
operating conditions and effects.
COMBUSTIBLE AND CORROSIVE MATERIALS:
Chemically aggressive substances can corrode the boiler and invalidate any guarantee.
• Do not store or use any combustible materials (paper, thinners, paints, propellants, cleaning agents etc.) inside or within the
vicinity of the appliance.
FITTINGS AND MODIFICATIONS:
Only a competent engineer can remove the boiler case and carry out any work, in accordance with the Gas Safety (Installation and
Use) Regulations.
• Do not remove the boiler case.
Any misuse or unauthorised modifications to the boiler, flue or associated accessories and heating system will invalidate the
guarantee.
• Do not modify the boiler or flue system in any way.
Worcester, Bosch Group accepts no liability arising from any such actions. This does not affect your statutory rights.

6
GENERAL INFORMATION
Greenstar i System Compact – 6 720 807 727 (2013/05)
2 GENERAL INFORMATION
SERVICING
• The boiler must be serviced regularly by a competent, qualified person, such as a Worcester service engineer or other Gas Safe
registered engineer.
• Always use original spares, to help maintain the efficiency, safety and reliability of the boiler and have the Service Record
completed in the Benchmark Checklist.
The completed Benchmark Checklist will be required in the event of any guarantee work and may be required by the local Building
Control Inspector.
BENCHMARK STANDARD
The Benchmark initiative is a code of practice to encourage the correct installation, commissioning
and servicing of domestic central heating boilers and system equipment.
A “checklist” is dispatched with every boiler. This is a vital document that needs to be completed
by the installer at the time of installation. It confirms that the boiler has been installed and
commissioned according to the manufacturer's instructions.
The log book provides space for the recording of regular servicing of the boiler/heating system and this can become a valuable
document when, for example, you wish to sell the property. The log book 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
Ensure that the service engineer completes the Service Record in the Benchmark Checklist after each service. The
Benchmark Checklist and service interval record can be found at the rear of the Installation, Commissioning and
Servicing Instructions.

7
CONTROLS
Greenstar i System Compact – 6 720 807 727 (2013/05)
3 CONTROLS
▶ To gain access to the boiler controls pull the flap down using the curved flap handle.
Fig. 1 Basic boiler controls
Boiler
Controls
1Service menu/back button 9 Scroll down button
2Service engineer symbol = boiler is set to maximum
or minimum output for service
10 The blue light is ON when the boiler is in an
operational mode.
It will also flash to indicate a fault.
3Eco button*
4Reset button 11 Position for optional programmer
5Boiler display 12 Hot water temperature control*
6Central heating temperature control 13 Diagnostic port**
7Scroll up button
8OK - Select/confirmation button 14 Central heating system pressure gauge
* Requires optional integral diverter kit to be functional ** for Worcester service engineer use only
6720643358-02.1Wo
1 3 65 7 8 9 10 11 12 13 1442

8
CONTROLS
Greenstar i System Compact – 6 720 807 727 (2013/05)
DISPLAY SYMBOLS
SCREEN DISPLAY BRIEF DESCRIPTION EXPLANATION
All possible screen symbols This screen is displayed briefly during boiler start
up and shows all the symbols that could be
displayed on the screen.
Numerical display Displays a temperature setting or boiler status
code.
Text display Display PreHeat or Eco, or the Alert code
Hot water Displays this symbol during a DHW demand, if the
optional integral diverter valve kit is fitted.
Central Heating Displays this symbol during central heating
demand.
Service engineer mode Displays during service when the boiler is set to
maximum or minimum output.
Alert Displays along with the boiler status code and
diagnostic code during a fault condition.
Service mode Displays when a qualified service engineer is in
the service menus.
Burner on The boiler is in operation and the flame is alight.
Centigrade indication Displays next to the temperature reading.
Confirmation This symbol confirms a manual change.
Maintenance codes A code displayed with an H and a number relates
to a maintenance issue. This is not a boiler fault
but an indication that something will need
attention concerning the boiler.
The example shown is H13 Service interval
reached, the boiler requires servicing.
Call your installer or Worcester Bosch Group to
organise a service visit.
°C
°
F
°C
°C
°F
H 13

9
CONTROLS
Greenstar i System Compact – 6 720 807 727 (2013/05)
3.1 OPERATING THE BOILER
3.1.1 BOILER DISPLAY
This is typical of the display when the boiler is not supplying a heat demand.
The display will not be backlit and the internal temperature of the boiler is indicated.
3.1.2 SETTING THE BOILER FLOW TEMPERATURE
1. Turn the central heating temperature control knob to the desired flow temperature between
30 and 82°C, this will be indicated on the digital display. This is not the room temperature but the flow temperature through the
radiators.
The “e” point provides guidance for the maximum temperature setting for optimum energy efficiency.
2. The radiator symbol will be displayed to confirm that the heating mode is being adjusted.
3. The value is displayed during this process, after five seconds the boiler display will return to the default screen.
Fig. 2 Central heating temperature control
▶ Comfort levels within rooms should be controlled by your thermostatic radiator valves and/or room thermostat.
max
min
2
3
1
04
bar
1
ok
eco
reset
e
max
min
°C
°F
°C
°F
6720807727-01.1Wo
max
min
2
3
1
04
bar
1
ok
eco
reset
e
max
min
°C
°F
Eco
1.
6720643358-03.1Wo
°C
°F
Eco
2.
3.

10
CONTROLS
Greenstar i System Compact – 6 720 807 727 (2013/05)
3.1.3 BOILER FLOW FUNCTION
If a heat demand occurs, the radiator and flame symbols will be displayed
If the domestic hot water control is adjusted or the “eco” button is pressed:
▶ N/A is displayed briefly.
▶ If the optional integral diverter valve is fitted, PreHeat or Eco will be displayed.
Fig. 3
3.1.4 SETTING THE FLOW TEMPERATURE FOR DOMESTIC HOT WATER SYSTEM
1. Turn the hot water temperature control knob to the desired level between 40 and 70°C, this will be shown on the digital display.
Fig. 4 Hot water temperature
▶ The tap symbol will be displayed to confirm that the hot water is being adjusted.
▶ After five seconds the boiler display will return to the default screen.
An internal or external timer/programmer coupled with the optional integral diverter valve kit with cylinder
temperature sensor is required to be able to set the hot water temperature.
If an FR110 or FW100 controller is also fitted, in conjunction with the diverter valve, they assume control over the
delivered temperatures, reducing the effect of the temperature controls. Set both to maximum.
An external timer may be fitted instead of an internal timer.
max
min
2
3
1
04
bar
1
ok
eco
reset
e
max
min
°C
°F
6720807727-05.1Wo
°C
°F
max
min
2
3
1
04
bar
1
ok
eco
reset
e
max
min
°C
°F
°C
°F
1.
6720807727-03.1Wo

11
CONTROLS
Greenstar i System Compact – 6 720 807 727 (2013/05)
3.1.5 DOMESTIC HOT WATER PRE-HEAT
▶ The hot water cylinder (when selected by the timer) is heated more regularly to reduce the time taken to deliver hot water.
Pre-heat is enabled by default, during the initial boiler start up and the text “PreHeat” will be displayed to confirm this state.
▶ If a cylinder demand occurs, the tap and flame symbol will be displayed.
Fig. 5 Preheat mode
3.1.6 DOMESTIC HOT WATER ECO MODE
Eco mode is an energy saving feature which disables the Pre-heat function and heats the cylinder less regularly.
Selecting Eco mode will use less energy, because the boiler will maintain a slightly lower average temperature.
1. Press and hold the Eco button for at least four seconds to enter the energy saving Eco mode, when Eco mode is active, “Eco”
will be displayed.
Fig. 6 Eco mode
To exit Eco mode and return to PreHeat
▶ Press and hold the Eco button for at least four seconds and “PreHeat” will be displayed.
An external timer may be fitted.
An external timer may be fitted.
max
min
2
3
1
04
bar
1
ok
eco
reset
e
max
min
°C
°F
Preheat
6720807727-04.1Wo
°C
°F
PreHeat
eco
max
min
2
3
1
04
bar
1
ok
eco
reset
e
max
min
°C
°F
Eco
6720807727-02.1Wo
°C
°F
Eco
1.
eco

12
CONTROLS
Greenstar i System Compact – 6 720 807 727 (2013/05)
3.1.7 BOILER ALERT STATE
In the event of an alert, a fault code and an alert symbol will be displayed on the boiler display and the blue operation/fault light
will flash.
Refer to the Fault finding section on page 17 or press Reset to clear the problem.
Fig. 7 Alert state
3.1.8 BOILER RESET
1. To reset the boiler, press the reset button .
2. The text “Reset” and a tick symbol are briefly displayed.
▶ If the reset was successful the boiler will return to normal operation.
▶ If the reset was not successful then the alert code will be displayed again, and the blue operation/fault light will continue to flash.
Fig. 8 Reset
If the fault remains and cannot be cleared by pressing the reset button, contact Worcester, Bosch Group for
assistance on 0844 892 3000.
reset
max
min
2
3
1
04
bar
1
ok
eco
reset
e
max
min
°C
°F
227
°C
°F
227
6720643358-14.1Wo
reset
max
min
2
3
1
04
bar
1
ok
eco
reset
e
max
min
°C
°F
Reset
6720643358-09.1Wo
°C
°F
Reset
1.
2.
≈≈ 5 s5 s

13
CONTROLS
Greenstar i System Compact – 6 720 807 727 (2013/05)
3.1.9 TURNING THE CENTRAL HEATING OFF DURING THE SUMMER
▶ Turn your programmer/timer to the off position.
▶ Please refer to the programmer/timer manufacturer's instructions.
3.1.10 BOILER FROST PROTECTION
If you are leaving your property unoccupied during cold weather, please leave your programmer on constant and your room
thermostat set to 15°C.
▶ If the temperature within the boiler falls below 8°C the pump will run to circulate water and prevent the system freezing.
– If the temperature does not rise to 9°C within 30 minutes of the pump operating, the boiler will fire up to provide heat to bring
the temperature up.
▶ If the temperature within the boiler falls below 5°C the boiler will fire immediately, bringing the boiler temperature up to 15°Cto
avoid the possibility of the system freezing.
▶ This process will be repeated until such time that the boiler temperature does not drop below 5°C.
3.1.11 TURN OFF THE OPERATION/FAULT DIAGNOSTIC LIGHT (BLUE)
Your new Greenstar iSystem Compact boiler is designed to use as little electricity as possible during operation and in stand-by
mode. To further enhance your energy saving during stand-by, you may choose to deactivate the Operation/fault diagnostic light.
The light will still flash to alert you to a possible fault, but will stay off when the boiler is in stand-by mode. Please ask your installer
to activate this feature.
NOTICE: The boiler must be switched on with a gas supply in order for the built -in auto frost protection to work as
described.

14
SYSTEM PRESSURE
Greenstar i System Compact – 6 720 807 727 (2013/05)
4SYSTEMPRESSURE
4.1 SEALED HEATING SYSTEMS
This boiler is fitted to a sealed heating system which is pre-pressurised.
Your installer will advise you of the minimum and maximum pressure indicated on the pressure gauge.
▶ Check regularly that the pressure is maintained.
Fig. 9 Optimum system pressure when your boiler is cold (area A)
▶ Contact your installer or maintenance engineer if a permanent significant decrease or increase in pressure is indicated on the
pressure gauge.
The filling method will be an external filling loop, fitted valves and flexible hose.
NOTICE: To comply with Water Authority regulations you must disconnect the external filling loop after re-
pressurisation.
6720643356-11.1Wo
2
3
1
04
bar
1
A
Min
1 bar
1.5 bar
Max

15
SYSTEM PRESSURE
Greenstar i System Compact – 6 720 807 727 (2013/05)
4.2 EXTERNAL FILLING LOOP
Once the external filling loop has been located, follow the instructions for re-pressurising the system.
1. Unscrew blanking cap.
2. Attach the hose to the valves, screw on hand-tight.
3. Turn the handle/screwdriver slot through 90° to open the valves.
4. The handle/screwdriver slot will be in-line with the valves
Fig. 10 External filling loop
5. When the pressure reaches between the 1 and 1.5 bar marks (zone A), turn the handle/screwdriver slot back, through 90°, to
close the valve.
6. The handle/screwdriver slot will be at 90° to the valves
7. Remove the hose and replace the blanking caps.
NOTICE: External filling loops
▶ If the filling loop does not look like the one shown in the figure below or you cannot find your filling loop, contact
your installer.
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.
6720643356-12.2Wo
1. 2.
7.
3. 3.
4.4.
5.
5.
6.6.
2
3
1
04
bar
1
A
Min
1 bar
1.5 bar
Max

16
SERVICE CLEARANCES
Greenstar i System Compact – 6 720 807 727 (2013/05)
5 SERVICE CLEARANCES
Your installer will have provided adequate space around the boiler for safety and servicing access.
Fig. 11 Service clearances
6 MAINTAINING YOUR BOILER
Your new Greenstar gas-fired system boiler represents a long term investment in a reliable, high quality product.
In order to realise its maximum working life, and to ensure it continues to operate at peak efficiency and performance, it is essential
that your boiler receives regular servicing and maintenance checks from a competent person beyond the initial 2 year guarantee
period.
If you would like to know more about a Worcester, Bosch Group service contract, please tick the appropriate box on your guarantee
registration card.
If your Greenstar gas-fired boiler should fail to operate correctly or requires servicing please contact the Worcester, Bosch Group
Appointments Team (see rear cover for details).
Details of the boiler including the Gas Council number can be found on the front cover of these User Instructions and on the boiler
identification label on the boiler fascia.
The Gas Council number is also listed on the front cover of your Installation, Commissioning and Servicing Instructions.
CAUTION: Restricted space.
The boiler may overheat.
▶ Do not restrict this space with the addition of cupboards, shelves etc. next to the boiler.
* Minimum clearances to removable door
** Minimum clearance required for servicing
*** Height for either 60/100 flue or 80/125 flue
1060/1100mm***
880mm
300mm
400mm
170/210mm***
600mm**
5mm
5mm
200mm
20mm*
6720646608-122.1Wo

17
FAULT FINDING
Greenstar i System Compact – 6 720 807 727 (2013/05)
7 FAULT FINDING
In the event that the boiler stops functioning or does not perform as expected, you can carry out a few simple checks. These checks
are some of the most common causes and are listed in the table below. Should the problem persist or other alert codes are
displayed, then it will be necessary to contact the Worcester, Bosch Group.
Problem Cause Remedy
EA fault code flashing on
display
No gas supply/low gas supply pressure ▶ Contact your gas supplier.
Condensate outlet blocked ▶ If it is safe to do so, check your condensate pipe
outlet for blockages, such as ice or foreign
objects.
Flue blocked ▶ If it is safe to do so, check your flue outlet for
damage or blockages.
Desired room temperature is
not reached
Thermostatic radiator valve(s) set too
low
▶ Increase thermostatic radiator valve setting(s)
Temperature control for central heating
flow on boiler set too low
▶ Increase central heating flow temperature control
setting
Air trapped in heating system ▶ Bleed radiators and recharge heating system
Low system water pressure ▶ Re-pressurise the system, refer to page 15
Low temperature setting on the boiler
controls
▶ Increase settings on boiler controls
Desired room temperature too
high
Radiators are too hot ▶ Turn down thermostatic radiator valves/room
thermostat
▶ Reduce central heating temperature by turning
down the Central Heating control on boiler
Heating stays on for too long Clock is incorrectly set ▶ Check setting and adjust
No blue Operation/Fault
Indicator
Momentary power failure ▶ Disconnect boiler supply, wait a few seconds then
reconnect.
Energy saving feature is activated ▶ Ask your installer to reset the blue light
Hot water temperature too low Temperature set too low on boiler
controls*
▶ Check setting and adjust
Air trapped in heating system ▶ Bleed radiators and recharge heating system
Low system water pressure ▶ Re-pressurise the system, refer to page 15
Hot water temperature too high Temperature set too high on boiler
controls*
▶ Check setting and adjust
* This feature is only available if the optional integral diverter valve has been fitted.
Table 2 Fault finding

18
FAULT FINDING
Greenstar i System Compact – 6 720 807 727 (2013/05)
ALERT CODES
If the blue operation/fault indicator light onthe front of your boiler is flashing and a warning triangle is displayed with an alert
code on the screen, e.g. EA, reset your boiler, refer to page 12.
Press the Reset button for approximately one second, if the reset has been successful the word “Reset” will be displayed with
the tick mark to confirm that the reset was successful.
After a few seconds of a successful reset the boiler display will return to a normal display, the display sequence is shown in figure 12
below.
Fig. 12 Reset setting a fault condition
Due to the internal safety systems of your Greenstar iSystem Compact boiler, some codes cannot be cleared by a simple reset.
Please contact Worcester, Bosch Group for further assistance.
When calling Worcester, Bosch Group about a fault it may be useful to quote the alert code and three digit number under the alert
code, e.g. EA and 227.
If there is a fault that cannot be reset by you, the user, then a service engineer visit will be necessary.
7.1 EXTREME COLD WEATHER
In some 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.
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.
▶ Once the pipe has been thawed the boiler must be reset, press the reset button for one second and wait two to three minutes for
the boiler to restart.
▶ If the boiler does not restart, contact Worcester, Bosch Group Appointments team on: 0844 892 3000.
▶ Contact your installer in order to find a permanent solution to the problem.
WARNING: Falling hazard!
Failure to follow this guidance may result in personal injury.
▶ Only attempt to thaw a condense pipe that is at ground level, and that is easily accessible.
▶ Never attempt to thaw a condense pipe that is at height.
CAUTION: Pipe damage
▶DO NOT use boiling water to thaw the condensate pipe!
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19
FAULT OR BREAKDOWN
Greenstar i System Compact – 6 720 807 727 (2013/05)
8 FAULT OR BREAKDOWN
This boiler is supported in the UK and Eire by Worcester, Bosch Group.
Specialist Service Engineers are available to attend a breakdown occurring on this boiler.
• No charge will be made for parts and/or labour providing:
A boiler fault is found and the appliance has been installed within the last 24 months. Reasonable evidence of this must be
supplied on request. i.e. the Benchmark Checklist.
• A call-out charge will be made where:
– The boiler has been installed for over 24 months.
– Evidence cannot be provided that the first year service inspection has been carried out (i.e. an entry in the Benchmark
Checklist).
– Our Field Service Engineer finds no fault with the boiler.
– The cause of breakdown is misuse or with other parts of your plumbing/heating system, or with equipment not supplied by
Worcester, Bosch Group.
TECHNICAL SUPPORT
In the event of a boiler fault or breakdown please contact Worcester, Bosch Group appointments team on 0844 892 3000.
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) for priority breakdown situations (no hot water and/or heating).
9ENVIRONMENT/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
We participate in the recycling programmes of the countries in which our products are sold to ensure optimum recycling.
All of our packaging materials are environmentally compatible and can be recycled.
Invoices for attendance and repair work carried out on this boiler by any third party will not be accepted.
No boiler fault is found on over 30% of all service calls.
In the case of a suspected fault, refer to the fault finding section of this guide.
USED APPLIANCES
▶ All Greenstar gas boilers are 100% recycleable.
The various assemblies can be easily dismantled and synthetic materials are marked accordingly. Assemblies
can be sorted by composition and passed on for recycling.

20
TIPS ON ENERGY SAVING
Greenstar i System Compact – 6 720 807 727 (2013/05)
10 TIPS ON ENERGY SAVING
HEATING ECONOMICALLY
The boiler provides a high level of comfort whilst keeping gas consumption and the environment effects as low as possible.
The gas supply to the burner is controlled according to the level of demand for heat. The boiler operates with a low flame if the
demand for heat reduces. The technical term for this process is modulating control.
Modulating control reduces temperature fluctuations and provides an even distribution of heat throughout the home. This means
that the boiler may stay on for relatively long periods of time but will use less gas than a boiler that continually switches on and off.
CENTRAL HEATING SYSTEMS WITH ROOM THERMOSTAT/THERMOSTATIC RADIATOR VALVES
With modern heating systems set around a 20°C heat loss, the optimum setting for a condensing boiler will be approximately
between the first and second segment on the central heating temperature control. 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, letterboxes and keyholes etc. are
reduced by using a suitable draught excluder.
CURTAINS
Lined curtains, or heavier full length curtains can provide excellent insulation. However,
always ensure that the curtains do not drape over radiators.
WARNING: Air vents
▶ Do not block or seal any air vents that are installed to ensure that the central heating boiler operates safely.