Worcester GREENSTAR Ri ErP Series User manual

UK/IE
User instructions
Wall hung RSF gas fired condensing regular boiler
GREENSTAR Ri ErP
6720813340-00.1Wo
For central heating systems
6 720 813 340 (2014/09)
If you smell gas:
▶ Well away from the building: call the National Gas Emergency
Service on 0800 111 999.
▶ L.P.G. boilers: Call the supplier’s number on the side of the gas
tank.
These appliances are for use with :
Natural Gas or L.P.G.
(Cat. II 2H 3P type C13, C33 & C53)
Model GC Number
Natural Gas 12Ri ErP 41-406-41
15Ri ErP 41-406-43
18Ri ErP 41-406-45
24Ri ErP 41-406-47
L.P.G. 12Ri ErP 41-406-42
15Ri ErP 41-406-44
18Ri ErP 41-406-46
24Ri ErP 41-406-48

2
Preface
Greenstar Ri ErP - 6 720 813 340 (2014/09)
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
combination appliance manufactured by Worcester, Bosch
Group. The company prides itself on manufacturing appliances
to the strictest quality control standards throughout every
stage of production.
Worcester, Bosch group has led the field in innovative
appliance design and performance for over 50 years. This
heritage means all our products are of exceptional quality and
proven reliability.
The Greenstar range in particular is extremely energy efficient,
offering you economical running costs and value for money. It is
amongst the top energy rated appliances available.
There is also the reassurance of our parts and labour guarantee
- backed up by Worcester Total Cover, an optional complete
maintenance scheme to keep your appliance operating at peak
condition and efficiency.

3
Contents
Greenstar Ri ErP - 6 720 813 340 (2014/09)
Contents
1 Key to symbols and safety instructions 4
1.1 Key to symbols 4
1.2 Safety precautions 4
2 General information 5
2.1 Energy efficiency 5
2.2 Servicing 5
2.3 Benchmark standard 5
2.4 User caution 5
3Controls6
3.1 Operating the boiler 7
3.1.1 Switching the boiler ON/Off 7
3.1.2 Setting the boiler flow temperature 7
3.1.3 Turning the central heating off during the
summer 8
3.1.4 Boiler frost protection 8
4 System pressure 9
4.1 Open vented heating systems 9
4.2 Sealed heating systems 9
4.3 External filling loop 10
5 Service Clearances 11
6 Maintaining your appliance 12
7FaultFinding13
7.1 Boiler reset 14
7.2 Extreme cold weather 15
8Faultorbreakdown16
9 Tips on energy saving 17
10 Environment / disposal 18
11 Your guarantee 18
12 Glossary 19

4
Key to symbols and safety instructions
Greenstar Ri ErP - 6 720 813 340 (2014/09)
1 Key to symbols and safety instructions
1.1 Key to symbols
Warnings
The following keywords are defined and can be used in this
document:
•NOTICE indicates a situation that could resultin damage to
property or equipment.
•CAUTION indicates a situation that could result in minor to
medium injury.
•WARNING indicates a situation that could result in severe
injury or death.
•DANGER indicates a situation that will result in severe
injury or death.
Important information
Additional symbols
Examples of additional symbols used
A numbered step in an action sequence
A sequence of numbered steps or actions carried out in a
specific order to complete a task.
1. First action
2. Second action
3. Third action
etc.
A step in an action sequence
A sequence of defined actions or steps carried out in order to
complete a task.
▶Action
▶Nextaction
▶etc
A reference to a related part in the document or to other
related documents.
To refer the reader to a specific figure/table/section within the
manual.
e.g. figure 1.
A reference number to identify or refer to a part or item.
In a related figure, items or parts identified by a sequential
number.
List entries, first and second levels
• A single component/item
• A component/list, made up of multiple parts/items.
– Sub component or sublist of main component/list.
–etc.
1.2 Safety precautions
If you smell gas:
A gas leak could potentially cause an explosion. If you smell gas,
observe the following rules.
▶ Prevent flames or sparks:
– Do not smoke, use a lighter or strike matches.
– Do not operate any electrical switches or unplug any
equipment.
– Do not use the telephone or ring doorbells.
▶ Turn off the gas at the meter or regulator.
▶ Open windows and doors.
▶ Warn your neighbours and leave the building.
▶ Prevent anyone from entering the building.
▶ Well away from the building: call the National Gas
Emergency Service on 0800 111 999.
▶ L.P.G. boilers: Call the supplier’s number on the side of the
gas tank.
Appliance operation:
This appliance can be used by children aged from 8 years and
above and persons with reduced physical, sensory or mental
capabilities or lack of experience and knowledge, if they have
been given supervision or instruction concerning the use of the
appliance, in a safe way, and understand the hazards involved.
Children shall not play with the appliance.
Cleaning and user maintenance shall not be made by children
without supervision.
Safety instructions in this document are
framed and identified by a
warning triangle which is printed on a grey
background.
This symbol indicates important information
where there is no risk to people or property.
Symbol Meaning
1. a numbered step in an action sequence
▶ a step in an action sequence
a reference to a related part in the document or to
other related documents
a reference number to identify or refer to a part or
item
•alistentry
– a list entry (second level)
Table 1
1

5
General information
Greenstar Ri ErP - 6 720 813 340 (2014/09)
Combustible and corrosive materials:
Chemically aggressive substances can corrode the appliance
and invalidate any guarantee.
• Do not store or use any combustible materials (paper,
thinners, paints, propellants, cleaning agents etc.) inside
the cupboard containing the appliance or within the vicinity
of the appliance.
Fittings and modifications:
Only a competent engineer can remove the appliance case and
carry out any work, in accordance with the Gas Safety
(Installation and Use) Regulations.
• Do not remove the appliance case.
Any misuse or unauthorised modifications to the appliance,
flue or associated accessories and heating system will
invalidate the guarantee.
• Do not modify the appliance or flue system in any way.
Worcester, Bosch Group accepts no liability arising from any
such actions. This does not affect your statutory rights.
Cleaning the appliance case:
Use a damp, soft cloth to clean the outer painted metal case of
the appliance, do not use chemicals or abrasive materials.
2 General information
2.1 Energy efficiency
Energy efficiency information is given in the Installation,
Commissioning and Servicing Instructions supplied with the
appliance.
2.2 Servicing
• The appliance must be serviced regularly by a competent,
qualified person, such as a Worcester service engineer or
other Gas Safe registered engineer.
• Always use original spares, to help maintain the efficiency,
safety and reliability of the appliance and have the Service
Record completed in the Benchmark Checklist.
The completed Benchmark Checklist will be required in the
event of any guarantee work and may be required by the local
Building Control Inspector.
2.3 Benchmark standard
The Benchmark initiative is a
code of practice to encourage
the correct installation,
commissioning and servicing of
domestic central heating
appliances and system
equipment.
A “checklist” is dispatched with every appliance and can be
found towards the back of the Installation, Commissioning and
Servicing Instructions. This is a vital document that needs to be
completed by the installer at the time of installation. It confirms
that the appliance has been installed and commissioned
according to the manufacturer's instructions.
The service record provides space for the recording of regular
servicing of the appliance/heating system and this can become
a valuable document when, for example, you wish to sell the
property. The service record will show a potential purchaser
that the heating system has received regular professional
maintenance and servicing during its lifetime.
The Benchmark initiative aims to:
• Raise standards among professional installers
• Build and maintain high safety standards in the industry
• Improve customer satisfaction levels
• Make a contribution to the nation's commitment to climate
change
2.4 User caution
• It isforbidden for any interference with the appliance other
than those actions allowed in this document.
Ensure that the service engineer completes
the Service Record in the Benchmark
Checklist after each service. The Benchmark
Checklist and service interval record can be
found at the rear of the Installation,
Commissioning and Servicing Instructions.
CAUTION: Incorrect use
▶ Any incorrect use can result in danger to
the householder.

6
Controls
Greenstar Ri ErP - 6 720 813 340 (2014/09)
3Controls
Fig. 1 Controls
1 Mains power ON/OFF knob 5 Maximum flow temperature position
2 Indicator/Diagnostic light “MAINS ON/OFF” (Blue) 6 Boiler reset position
3 Minimum flow temperature position 7 Burner ON indicator light (Green)
4 Flow temperature control knob
Table 2
6720813340-01.1Wo
14
32
76
5

7
Controls
Greenstar Ri ErP - 6 720 813 340 (2014/09)
3.1 Operating the boiler
3.1.1 Switching the boiler ON/Off
▶ Turn the “MAINS POWER” knob to 1 to switch ON the boiler.
▶ Turn the “MAINS POWER” knob to 0 to switch OFF the boiler.
Fig. 2 Switch ON/OFF boiler.
The boiler frost protection function will not work if the mains power knob is switch to OFF.
3.1.2 Setting the boiler flow temperature
1. Turn the central heating temperature control knob [1] to the desired level.
The temperatures range available is between approximately 35 to 82°C. This is not the room temperature but the flow
temperature through to the system (radiators and/or hot water cylinder).
2. When there is a demand for heat from the boiler, the burner indicator [2] will be illuminate to indicate that the boiler is firing.
Fig. 3 Central heating temperature control
6720813340-02.1Wo
1
ON
OFF
6720813340-03.1Wo
1
2
35ºC
82ºC

8
Controls
Greenstar Ri ErP - 6 720 813 340 (2014/09)
3.1.3 Turning the central heating off during the summer
▶ To turn your central heating off during warm periods:
▶ Set the programmer to OFF
– Please refer to the programmer manufacturer's instructions.
-or-
▶ Turn the room thermostat temperature down to minimum.
3.1.4 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, bringing the boiler temperature up to 12°C to 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.
Do not switch the boiler off at the mains power switch or mains fused spur.

9
System pressure
Greenstar Ri ErP - 6 720 813 340 (2014/09)
4Systempressure
4.1 Open vented heating systems
If the boiler is fitted to an open vented system, that is a system with a header tank, the pressure will be maintained automatically.
4.2 Sealed heating systems
If this boiler is fitted to a sealed heating system, the system will be pre-pressurised.
Your installer will have fitted a pressure gauge and filling loop so that the system can be monitored and adjusted as necessary.
Your installer will show you how to use the filling loop and advise you of the minimum and maximum pressure indicated on the
pressure gauge.
▶ Check regularly that the pressure is maintained.
Fig. 4 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 the 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

10
System pressure
Greenstar Ri ErP - 6 720 813 340 (2014/09)
4.3 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. 5 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.
▶ To comply with Water Authority regulations you must disconnect the external filling loop after re-
pressurisation.
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.
2
3
1
04
bar
1
A
Min
1 bar
1.5 bar
Max
6720806947-01.1Wo
1. 2.
7.
4. 4.
3.
3.
6. 6.
5.
5.

11
Service Clearances
Greenstar Ri ErP - 6 720 813 340 (2014/09)
5 Service Clearances
Your installer will have provided adequate space around the boiler for safety and servicing access.
Fig. 6 Service clearances
[*] Minimum clearances to removable door
[**] Minimum clearances required for servicing
[***] Height for either 60/100 flue or 80/125 flue above the boiler
CAUTION: Restricted space.
The boiler may overheat.
▶ Do not restrict this space with the addition of cupboards, shelves etc. next to the boiler.
6720813340-05.1Wo
5
m
m
5
m
m
6
0
0
mm
*
*
2
0
mm
*

12
Maintaining your appliance
Greenstar Ri ErP - 6 720 813 340 (2014/09)
6 Maintaining your appliance
Your new gas-fired appliance represents a long term investment in a reliable, high quality product.
Wipe the appliance casing with a soft clean cloth. Please do not use chemical cleaning products which may damage the paint finish.
In order to realise its maximum working life, and to ensure it continues to operate at peak efficiency and performance, it is essential
that your appliance receives regular servicing and maintenance checks from a competent person beyond the initial guarantee
period.
If your Greenstar gas-fired appliance should fail to operate correctly or requires servicing, please contact the Worcester, Bosch
Group Appointments Team (see rear cover for details).
Details of the appliance including the Gas Council number can be found on the front cover of these User Instructions and on the
appliance identification label on the appliance facia.
The Gas Council number is also listed on the front cover of your Installation, Commissioning and Servicing Instructions.

13
Fault Finding
Greenstar Ri ErP - 6 720 813 340 (2014/09)
7FaultFinding
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 of apparent faults and are listed in the table below. Should the problem persist or other alert
codes are displayed, then it will be necessary to contact Worcester, Bosch Group.
Problem Cause Remedy
Operation/fault light
(blue) flashing
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
appliance set too low
▶ Increase central heating flow temperature
control setting
Low temperature setting on the room thermostat ▶ Increase settings on room thermostat
Radiators are too
hot
Temperature control for central heating flow on
appliance set too low
▶ Reduce central heating temperature by turning
down the Central Heating control on appliance.
Note: This could prevent your property reaching
the desired temperature during cold weather
periods.
Desired room
temperature is too
high
Thermostatic radiator valve(s) are set too high ▶ Turn down thermostatic radiator valves/room
thermostat
Room thermostat is set too high ▶Turndownroomthermostat.
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.
Hot water
temperature too low
Temperature set too low on cylinder thermostat
control.
▶ Check setting and adjust
Hot water
temperature too
high
Temperature set too high on cylinder thermostat
control.
▶ Check setting and adjust
Table 3 Fault finding

14
Fault Finding
Greenstar Ri ErP - 6 720 813 340 (2014/09)
7.1 Boiler reset
In the event of a fault, the blue mains indicator light will flash if there is a fault.
To reset the boiler:
▶ Turn the Central heating temperature knob[1] anticlockwise to the “RESET” position [2] and hold for approximately five
seconds and then turn the knob back to the original temperature setting.
▶ When the boiler resets the mains indicator [3] will no longer be flashing and the boiler will function normally, dependant on the
programmer and room thermostat settings.
A reset fault condition will exist If the electrical power to the boiler has been interrupted. Reset the boiler as described above.
Fig. 7 Reset button and mains light
If the fault remains and cannot be cleared by resetting the boiler, contact Worcester, Bosch Group for assistance.
6720813340-04.1Wo
1
2
3

15
Fault Finding
Greenstar Ri ErP - 6 720 813 340 (2014/09)
7.2 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.
▶Thawthefrozenpipe.
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, refer to page 14.
Wait two to three minutes for the boiler to restart.
▶ If the boiler does not restart, contact Worcester, Bosch Group appointments team on: 0330 123 9339.
▶ 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!

16
Fault or breakdown
Greenstar Ri ErP - 6 720 813 340 (2014/09)
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 past 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 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) for priority breakdown situations (no hot water and/or heating).
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.

17
Tips on energy saving
Greenstar Ri ErP - 6 720 813 340 (2014/09)
9 Tips on energy saving
Heating economically
The appliance provides a high level of comfort whilst keeping gas consumption low and so minimising the environmental impact.
The gas supply to the appliance‘s burner is regulated according to the demand for heat. The appliance 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 appliance may stay on for relatively long periods of time but will use less gas than a appliance that continually switches on
and off.
Central heating systems with room thermostat/thermostatic radiator valves
With modern heating systems designed around a 20 °C heat loss across the system, the optimum setting for a condensing boiler will
be approximately mid-position on the central heating temperature control. The system must be balanced correctly and the radiators
may need upgrading.
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.
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 appliance operates safely.

18
Environment / disposal
Greenstar Ri ErP - 6 720 813 340 (2014/09)
10 Environment / 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.
11 Your guarantee
This boiler has a guarantee against faulty materials or workmanship for a period from the date of installation subject to the following
terms and conditions:
• During the period of this guarantee any components of the boiler which 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 boiler was correctly commissioned and, where
appropriate, the first year's service has been carried out to the satisfaction of Bosch Thermotechnology Ltd, when requested.
These should be documented as a part of the Benchmark Checklist.
• The boiler 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 Greenstar boiler 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. The Guarantee Registration
form is available on this same page and can be completed and submitted electronically.
Alternatively please telephone one of our Guarantee Registration advisors on 0330 123 2552.
Your statutory rights are not affected by the manufacturer’s guarantee.
For your own record:
Please ensure that the Benchmark Checklist has been completed by your installer or service engineer.
USED APPLIANCES
▶ All Greenstar gas boilers are 100% recycleable.
The various assemblies can be easily dismantled and synthetic materials are marked accordingly. Assemblies
can therefore be sorted by composition and passed on for recycling.
Model
Serial No.1)
1) See boiler identification label on boiler fascia or Benchmark Checklist in the back of the Installation, Commissioning & Servicing
Instructions.
Type/size
Date of installation
Name of Installer
Telephone number of Installer
Table 4

19
Glossary
Greenstar Ri ErP - 6 720 813 340 (2014/09)
12 Glossary
Central heating systems
All radiators must be heated at an even rate. If the top of a radiator is at a lower temperature than the bottom then it should be bled
by releasing air through the bleed screw at the top of the radiator.
Ask your installer to show you how this is done.
If this boiler is fitted to a sealed system and water leaks are found or if excessive bleeding is required, then a service engineer must
be contacted to inspect the installation and rectify any fault.
Only additives that are compatible with aluminium may be used in the system. Any incompatible additive used will invalidate the
warranty.
Pluming and condensate drain
This is a condensing boiler and the flue terminal will, at times give out a plume of water vapour. This is quite normal.
The boiler produces condensate which is discharged regularly by a syphon within the boiler via a plastic pipe to a drain. This pipe
must not be blocked or altered in any way.
Room thermostat / programmer
A room thermostat / programmer must be fitted to control the central heating. This controls the times and temperatures of the
central heating, preventing the boiler from firing unnecessarily. Refer to the instructions supplied with the thermostat and
programmer for further information.
Thermostatic radiator valves
Thermostatic radiator valves must be fitted in sleeping accommodation. It is recommended that this type of valve is fitted to all but
one of the radiators. The remaining radiator, where the room thermostat is located, must be uncontrolled and left open.
Pump over run function
After the boiler has finished a demand for central heating or hot water, the pump may continue to run for a short while to dissipate
the heat from within the boiler.
Pump anti-seizure
If there has been no heating demand for 24 hours the boiler will run the system pump for a few seconds to reduce the possibility of
pump seizure during long periods of inactivity.

WORCESTER, BOSCH GROUP:
TECHNICAL SUPPORT: 0330 123 3366
APPOINTMENTS: 0330 123 9339
SPARES: 0330 123 9779
LITERATURE: 0330 123 9119
TRAINING: 0330 123 0166
SALES: 0330 123 9669
Worcester, Bosch Group
Cotswold Way, Warndon, Worcester WR4 9SW.
Tel. [phone]
Worcester, Bosch Group is a brand name of
Bosch Thermotechnology Ltd.
worcester-bosch.co.uk
6 720 813 340 (2014/09)