Bosch Worcester GREENSTAR HEATSLAVE II EXTERNAL... User guide

Installation, Commissioning and Servicing instructions
Floor standing oil fired condensing combination boiler balanced flue
Greenstar Heatslave II External 2022+
12/18, 18/25 & 25/32
6 720 805 210-00.1TL
For fully pumped sealed central heating systems and mains pressure domestic hot water.
These appliances are for use with Kerosene (Class C2) only.
6 721 843 980 (2022/01) UK/IE

Contents
Greenstar Heatslave II External 2022+ 6 721 843 980 (2022/01)2
Contents
1 Key to symbols and safety instructions . . . . . . . . . . . . . . . . . . . 3
1.1 Key to symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 General safety instructions . . . . . . . . . . . . . . . . . . . . . . . . 3
2 Installation regulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1 Complying with the building regulations . . . . . . . . . . . . . 4
3 Appliance information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1 General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.2 Technical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.3 Energy efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.4 Layout & components . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4 Pre-Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.1 Cleaning primary systems . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.2 Mains supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.2.1 Electrical supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.2.2 Water supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.2.3 Oil supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.2.4 Pipework . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4.2.5 Boiler isolation valve . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.3 Water systems and pipework . . . . . . . . . . . . . . . . . . . . 11
4.4 Condensate pipework . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.4.1 Condensate disposal connections . . . . . . . . . . . . . . . . 12
4.4.2 Soak away . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.5 Pressure relief pipework . . . . . . . . . . . . . . . . . . . . . . . . 14
4.6 Boiler locations and clearances . . . . . . . . . . . . . . . . . . 14
4.7 Flue gas system considerations . . . . . . . . . . . . . . . . . . 15
4.7.1 Combustion air quality . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.7.2 Flue terminal positions . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.8 Flue options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.8.1 Cabinet mounted balanced horizontal flue options . . 18
4.8.2 Plume management . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.8.3 Plume management considerations . . . . . . . . . . . . . . . 19
5 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
5.1 Unpacking the boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
5.2 Pipework and flue positions . . . . . . . . . . . . . . . . . . . . . 21
5.3 Boiler installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
5.4 Flue installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
5.4.1 Flue Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
5.4.2 Rear Flue options _ Greenstar - all models . . . . . . . . . . 22
5.4.3 Side Flue options - Heatslave II . . . . . . . . . . . . . . . . . . . 23
5.4.4 All flue options, final assembly . . . . . . . . . . . . . . . . . . . 24
5.4.5 Terminal guard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
5.4.6 Flue damper installation . . . . . . . . . . . . . . . . . . . . . . . . 25
5.4.7 Installation notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
5.4.8 All flue options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
5.5 Combustion chamber . . . . . . . . . . . . . . . . . . . . . . . . . . 25
5.6 Pipework connections . . . . . . . . . . . . . . . . . . . . . . . . . 26
5.7 Oil burner and pump . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
5.8 Refitting components . . . . . . . . . . . . . . . . . . . . . . . . . . 28
5.9 Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
5.10 Electrical schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
5.11 Weather compensation . . . . . . . . . . . . . . . . . . . . . . . . . 32
6 Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
6.1 Pre-commissioning checks-appliance . . . . . . . . . . . . . . 33
6.2 Filling the system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
6.3 Starting the appliance . . . . . . . . . . . . . . . . . . . . . . . . . . 34
6.3.1 Single pipe gravity feed systems: . . . . . . . . . . . . . . . . . 34
6.3.2 Double pipe sub-gravity feed systems and single pipe
suction lift with de-aerator: . . . . . . . . . . . . . . . . . . . . . . 34
6.3.3 Burner head setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
6.3.4 Boiler lockout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
6.3.5 Switching the appliance on/off . . . . . . . . . . . . . . . . . . . 36
6.3.6 Selecting Service Menus . . . . . . . . . . . . . . . . . . . . . . . . 37
6.3.7 Finish commissioning boiler checks . . . . . . . . . . . . . . . 39
6.4 Water treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
6.5 Finishing commissioning - Appliance . . . . . . . . . . . . . . 41
6.5.1 Appliance guarantee . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
7 Service and spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
7.1 Inspection and service . . . . . . . . . . . . . . . . . . . . . . . . . . 42
8 Fault finding and diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
8.1 Status cause codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
8.2 Information menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
8.3 Service menus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
8.4 Factory reset and fault codes . . . . . . . . . . . . . . . . . . . . . 49
8.4.1 Factory reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
8.4.2 Locking or Blocking fault conditions . . . . . . . . . . . . . . . 49
8.4.3 Cause and fault codes . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
8.5 DHW function chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
8.6 CH function chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
8.7 Protection functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
8.8 Solar compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
8.9 Burner diagnostics mode . . . . . . . . . . . . . . . . . . . . . . . . 54
8.10 Riello digital control boxes . . . . . . . . . . . . . . . . . . . . . . . 54
8.10.1 Control box LED codes . . . . . . . . . . . . . . . . . . . . . . . . . . 54
8.10.2 Fault finding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
8.11 Flame sensing photocell . . . . . . . . . . . . . . . . . . . . . . . . . 56
8.12 Oil supply vacuum testing . . . . . . . . . . . . . . . . . . . . . . . . 56
8.13 Air pressure switch, flue overheat reset and tank overheat
reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
8.14 Air pressure switch connections . . . . . . . . . . . . . . . . . . 57
8.15 System gassing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
8.16 Oil appliance commissioning checklist . . . . . . . . . . . . . 59
8.17 Service interval record . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Key to symbols and safety instructions
Greenstar Heatslave II External 2022+ - 6 721 843 980 (2022/01) 3
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 result in 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
Abbreviations used in this manual
Read these instructions before starting any installation
These instructions are applicable to the Worcester appliance model(s)
stated on the front cover of this manual only and must not be used with
any other make or model of appliance.
The instructions apply in the UK and Eire only and must be followed
except for any statutory obligation.
This appliance must be installed by a competent person, failure to install
correctly could lead to prosecution.
1.2 General safety instructions
These installation instructions are intended for heating engineers,
plumbers, and electricians.
▶ Read any installation instructions (boiler, heating controls, etc.)
carefully before starting the installation.
▶ Observe the safety instructions and warnings.
▶ Observe national and regional regulations, technical rules and
guidelines.
▶ Record all work carried out.
Oil fumes or leaks from the appliance
If you smell oil fumes, observe the following rules.
▶ Extinguish any naked flames
▶ Isolate the electrical supply
▶ Isolate the fuel supply to the boiler
▶ Rectify the fault
Health and safety
The appliance contains no asbestos and no substances have been used
in the construction process that contravene the COSHH Regulations
(Control of Substances Hazardous to Health Regulations).
Where applicable, the CE mark indicates compliance with relative
EU Directives.
Combustible and corrosive materials
Do not store or use any combustible materials (paper, thinners, paints
etc.) inside or within the vicinity of the appliance.
The combustion air must be kept clear of chemically aggressive
substances which can corrode the appliance and invalidate any
warranty.
Handling instructions and guidelines
It is advised that more than one person is involved in the transfer of the
packaged appliance from the van to the point of installation.
It is advised that no attempt should be made to move the packaged
appliance without the use of a suitable truck.
At all times the correct method for handling heavy objects should be
strictly observed.
▶ Lift only a manageable weight, or ask for help.
▶ When lifting, bend the knees, and keep the back straight and feet
apart.
▶ Do not lift and twist at the same time.
▶ Lift and carry items close to the body.
▶ Wear protective clothing and gloves to protect from any sharp edges.
Intended use
This boiler must only be used as a heat appliance in a heating system for
domestic purposes.
Any other use is considered inappropriate. Any damage that results from
such use is excluded from liability.
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.
Warnings in this document are identified by a warning
triangle printed against a grey background.
Keywords at the start of a warning indicate the type and
seriousness of the ensuing risk if measures to prevent
the risk are not taken.
This symbol indicates important information where
there is no risk to people or property.
Symbol Explanation
▶ Steps in an action sequence
Cross-reference to another part of the document
• List entry
– List entry (second level)
Table 1
ØDiameter
CH Central Heating
DHW Domestic Hot Water
DCW Domestic Cold water
HE Heat Exchanger
TRV Thermostatic Radiator Valve
IP Ingress Protection
CF Conventional Flue
RS Room Sealed
N/A Not Applicable
SEDBUK Seasonal Efficiency of Domestic Boilers in the UK
OFTEC Oil Firing Technical Association for the Petroleum Industry
WRAS Water Regulations Advisory Scheme
IET Institution of Engineering and Technology
DWTA Domestic Water Treatment Association
LABC Local Authority Building Control Body
Table 2

Installation regulations
Greenstar Heatslave II External 2022+ 6 721 843 980 (2022/01)4
Installation, commissioning and servicing
Installation, commissioning and servicing must only be carried out by a
competent registered engineer.
▶ Only use original spares.
▶ Advise the user to have the system regularly serviced by a
competent, qualified engineer (such as OFTEC registered personnel)
using approved spares, to help maintain the economy, safety and
reliability of the appliance.
Fitting and Modification
Fitting the appliance and any controls to the appliance may only be
carried out by a competent engineer in accordance with these
instructions and the relevant Installation Regulations.
Flue systems must not be modified in any way other than as described in
the fitting instructions.
Any misuse or unauthorised modifications to the appliance, flue or
associated components and systems could invalidate the warranty.
The manufacturer accepts no liability arising from any such actions,
excluding statutory rights.
Electrical work
Electrical work must only be carried out by a qualified electrician.
▶ Before starting electrical work:
– Isolate the mains electrical supply and secure against
unintentional re-connection.
– Check for zero potential.
▶ Also observe connection diagrams of other system components.
Handover to the user
When handing over, instruct the user how to operate the heating system
and inform them about its operating conditions.
▶ Explain how to operate the heating system and draw the user's
attention to any safety-relevant action.
▶ Explain that modifications and repairs must only be carried out by an
authorised contractor.
▶ Advise the user to have the system serviced annually by a competent,
qualified engineer, such as an OFTEC registered engineer.
▶ Leave the installation instructions with the completed
commissioning form with the homeowner.
2 Installation regulations
2.1 Complying with the building regulations
This heating appliance forms part of the controlled services for the
building. It is law that all controlled services for buildings must comply
with building regulations. You must be able to satisfy your Local
Authority Building Control Body (LABC) that the work carried out
concerning the installation and commissioning of this heating appliance
has been carried out to a satisfactory standard.
OFTEC operate a competent persons scheme and registered installers
are able to certify that their work complies with building regulations.
Under the scheme;
• OFTEC must be informed about every installation.
• OFTEC will issue a building regulations compliance certificate to the
householder and will notify the LABC.
OFTEC provide controlled document forms CD10 and CD11 for use
during installation and commissioning respectively.
Other organisations operate self-certification schemes e.g. NAPIT and
BESCA Ltd. and it may be possible for installers who are members of
these organisations to self certify their work.
Alternatively you must submit a building control notice to the LABC
before installing any boiler. The LABC will then arrange regular
inspection visits during the work to ensure that the installation complies
with the regulations.
Installation
Failure to install appliances correctly could lead to prosecution.
The appliance should be installed by a competent person. The person
installing the appliance should be aware of the Healthand Safety at Work
Act and take appropriate action to ensure that the regulations are
adhered to. In order to give optimum efficiency and trouble free
operation the appliance must be commissioned by a qualified OFTEC
engineer.
The compliance with a British Standard does not, in itself, confer
immunity from legal obligations. In particular the installation of this
appliance must be in accordance with the relevant requirements of the
following British Standards and regulations in respect of the safe
installation of equipment:
The Building Regulations Part G, Part J and L1 England and Wales;
Part F, Part G and Part J Section III Scotland; Part L and Part F Northern
Ireland.
Local water company bye-laws.
The Control of Pollution (Oil) Regulations.
OFTEC Standards.
Where no specific instruction is given, reference should be made to the
relevant codes of practice.
Installations in Eire (Republic of Ireland)
The Installation must be performed by a competent and suitably trained
person in accordance with the following Eire regulations.
Current Building Regulations - Republic of Ireland
ETCI rules for electrical installation
For further guidance see
OFTEC Technical book three - Regional requirements: Republic of
Ireland
BS 5410: part 1: Code of practice for Liquid Fuelled Boilers.
BS 799: part 5: Specification for Oil Storage Tanks
BS 7593: Code of Practice for treatment of water in
domestic hot water central heating systems.
BS 5449: part 1: Specification for forced circulation hot water
central heating for domestic premises.
BS EN 12828: Heating systems in buildings.
Design for water-based heating systems
BS 7291: Thermoplastic pipes and associated fittings for
hot and cold water for domestic purposes and
heating installations in buildings
BS 7074: part 1: Application, selection and installation of
expansion vessels and ancillary equipment for
sealed water systems.
BS 1254-2: Copper and copper alloys plumbing fittings part
2: Fittings with compression ends for use with
copper tubes.
BS 7671: IET Wiring Regulations, current edition.
BS 1362: Specification for general purpose fuse links for
domestic and similar purposes.

Appliance information
Greenstar Heatslave II External 2022+ - 6 721 843 980 (2022/01) 5
3 Appliance information
3.1 General information
Standard package
Fig. 1 Standard package
[A] Floor standing oil fired condensing combination boiler for sealed
central heating and mains fed domestic hot water.
[B] Flue damper
[C] Literature pack
[D] 100mm Ø services duct.
[E] Balanced flue kit
[F] Utility key
[G] Mains supply socket
[H] ErP label
Check List (Literature pack)
3.2 Technical data
Item Qty
Greenstar Heatslave II External Installation/
Servicing Instructions
1
Instructions 1
Hardware Pack 1
6720821722-02.1Wo
D
F
E
GH
A
C
B
Description Units 12/18 18/25 25/32
Central heating
Primary water capacity (total) litres 62 63 64
Available pump head (20°C
difference) at max. output
metres
water
4.7 4.0 4.2
Max. permissible system
operating pressure in accordance
with WRAS guidelines
bar 2.5 2.5 2.5
Flow restrictor colour Lime Beige Grey
Domestic Hot Water
Maximum flow rate (15%) litres/min 15 18 22
Minimum inlet pressure
(dynamic) for maximum flow rate
bar 1.5 1.2 1.6
Maximum hot water temperature
rise for 90 litres draw off (@max
flow rate)
°C 40 40 40
Flue
Exit flue gas mass flow kg/hr 29 40 51
Pipework connections
Fuel line (compression) mm 10 10 10
CH flow mm 22 22 28
CH return mm 22 22 28
Water main inlet mm 15 15 15
DHW outlet mm 22 22 22
CH drain hose
connection
Condensate (polypropylene) mm 21.5 21.5 21.5
Electrical
Electrical power supply voltage AC. ..V 230 230 230
Frequency Hz 50 50 50
Sensors & Thermostats
CH control range °C 50/82 50/82 50/82
Slave tank control range °C 55/84 55/86 55/88
Boiler manual reset overheat set
point
°C 105 105 105
Flue manual reset overheat
thermostat set point
°C 110 110 110
Tank manual reset overheat
thermostat set point
°C 95 95 95
General data
Maximum hearth temperature °C <100 <100 <100
SEDBUK 2009 % 89.0 88.9 88.8
SEDBUK 2005 % 90.2 90.1 89.9
Appliance protection rating IP 45 45 45
Weight (excluding packaging) kg 151 154 158

Appliance information
Greenstar Heatslave II External 2022+ 6 721 843 980 (2022/01)6
3.3 Energy efficiency
The following product data satisfy the requirements of the EU Regulations No. 811/2013 and No. 812/2013 supplementing Directive 2010/30/EU.
Product data Symbol Unit 7731600263 7731600264 7731600265
Product type – – Greenstar Heatslave II
External 2022+ 12/18
Greenstar Heatslave II
External 2022+ 18/25
Greenstar Heatslave II
External 2022+ 25/32
Condensing boiler – – Yes Yes Yes
Low temperature boiler – – No No No
B1 boiler – – No No No
Cogeneration space heater (CHP) – – No No No
Combination heater – – Yes Yes Yes
Rated heat output Prated kW 18 25 32
Seasonal space heating energy efficiency s%92 92 92
Energy efficiency class – – A 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 18.2 25.1 32.9
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 5.6 7.8 10.0
Useful efficiency
At rated heat output and high temperature
regime 1) 4% 91.8 91.9 91.5
At 30% of rated heat output and low
temperature regime 2) 1% 98.5 97.8 97.3
Auxiliary electricity consumption
At full load elmax kW 0.165 0.159 0.150
At part load elmin kW 0.053 0.049 0.047
In standby mode PSB kW 0.002 0.002 0.002
Other items
Standby heat loss Pstby kW 0.166 0.159 0.161
Ignition burner power consumption Pign kW000
Emissions of nitrogen oxides NOx mg/kWh 110 103 109
Annual energy consumption QHE GJ 57 79 103
Sound power level, indoors LWA dB(A) N/A N/A N/A
Additional data for combination heaters
Declared load profile – – XL XL XL
Daily electricity consumption Qelec kWh 0.210 0.176 0.199
Annual electricity consumption AEC kWh 46 39 44
Daily fuel consumption Qfuel kWh 31.232 32.834 32.426
Annual fuel consumption AFC GJ 25 26 26
Water heating energy efficiency wh %66 63 64
Water heating energy efficiency class – – B B B
Table 3 Product data for energy consumption

Appliance information
Greenstar Heatslave II External 2022+ - 6 721 843 980 (2022/01) 7
3.4 Layout & components
The diagram below excludes the top, front and RH side casing panels.
Fig. 2 Boiler layout
4
8
10
11
12
13
14
15
16
17
18
20
21
23
9
7
19
31
32
30
29
2
6
7
5
22
43
45
44
33
3
27
28
24
25
26
1
40 41
39
38
37
36
35
34
42 43
6720821722-01.1Wo

Pre-Installation
Greenstar Heatslave II External 2022+ 6 721 843 980 (2022/01)8
Legend:
[1] Flue overheat reset
[2] Air pressure switch
[3] Flue overheat thermostat phial
[4] Air intake duct
[5] Pressure relief valve
[6] Heat exchanger flow pipe
[7] Condensate drain pipe
[8] Secondary heat exchanger drain
[9] Condensate drain pipe
[10] Condensate outlet
[11] Condensate trap
[12] Oil isolating valve
[13] Base plate and drip tray
[14] Combustion chamber access cover
[15] Expansion vessel
[16] Primary heat exchanger drain
[17] Heatslave tank
[18] Riello burner
[19] Heatslave tank drain
[20] Flue manifold cover
[21] Flue gas sample point plug
[22] Control box assembly
[23] Service mode button
[24] Heatslave tank temperature control knob
[25] Diagnostic port (Service engineer only)
[26] System pressure gauge
[27] Central heating temperature control knob
[28] LCD Display
[29] Drain point
[30] Heatslave tank overheat manual reset
[31] Circulating pump
[32] Diverter valve assembly
[33] Automatic air vent
[34] DHW flow turbine
[35] Heatslave tank temperature sensor
[36] DHW Heat exchanger
[37] Mians inlet temperature sensor
[38] DHW pressure relief valve
[40] Primary heat exchanger manual air vent
[41] Flow temperature sensor
[42] Primary heat exchanger safety sensor
[43] Secondary heat exchanger manual air vent
[44] Secondary heat exchanger
[45] Pressure relief valve
4 Pre-Installation
4.1 Cleaning primary systems
BEFORE CLEANING THE SYSTEM:
▶Ensure that the system and pipe work is in good working order.
▶Where possible keep the existing boiler/circulating pump in
place when flushing the system.
FOLLOW THE GUIDANCE OF BS7593
Treatment of water in domestic hot water central heating and also the
flushing guidelines below.
FLUSHING THE SYSTEM
▶ Fill the system with cold water and check for leaks.
▶ Open all drain cocks and drain the system.
▶ Close drain cocks and add a suitable flushing agent at the correct
strength for the system conditions in accordance with the
manufacturer‘s instructions.
▶ Circulate the flushing agent before the boiler is fired up.
▶ Run the boiler/system at normal operating temperature as directed
by the manufacturer of the flushing agent.
▶ Drain and thoroughly flush the system to remove the flushing agent
and debris.
▶ It may be necessary to use a power flushing machine to aid the
cleansing procedure in some circumstances.
▶ Close the drain cocks and refill with fresh water and a suitable
inhibitor.
▶ Vent any air from the boiler and system.
INHIBITOR
Add a suitable inhibitor or combined inhibitor/anti-freeze, if the system
is exposed to freezing conditions, to the heating system in accordance
with the DWTA code of practice and inhibitor manufacturer‘s guidelines.
Water treatment products
Suitable water treatment products can be obtain from the following
manufacturers:
Before installation
▶ All the following Pre-Installation sections must be
read and requirements met before starting boiler or
flue installations.
CAUTION: Mains power
▶ Isolate the mains supplies before starting any work
and observe all relevant safety precautions.
Protect the boiler
▶ Debris from the system can damage the boiler and
reduce efficiency. Failure to comply with the
guidelines for the use of water treatment with the
appliance will invalidate the appliance warranty.
▶ It is recommended that a primary water cleanser is
fitted to the system. Worcester offers a system filter
that helps remove both magnetite and non-magnetic
debris.
WARNING: Sealing agents
▶ In cases where all attempts to find a system micro
leak have failed, Worcester, Bosch Group supports
the use of Fernox F4 leak sealer.
ADEY 01242 546700 - www.adey.com
FERNOX 0330 100 7750 - www.fernox.com
SENTINEL 01928 704330 - www.sentinelprotects.com/uk

Pre-Installation
Greenstar Heatslave II External 2022+ - 6 721 843 980 (2022/01) 9
Artificially softened water
It is possible to have an ion exchange water softener fitted to the cold
water system of the property. However, the boiler requires an untreated
cold water connection taken from the mains supply, before the water
softener, to the primary water filling point of the heating system.
Alternatively there are water softening/treatment devices that do not
adjust or alter the pH levels of the water. With these devices it may not
be necessary to provide an untreated water by-pass to the primary water
filling point of the heat system.
4.2 Mains supply
4.2.1 Electrical supply
• Supply: 230V - 50 Hz
• Cable: PVC insulated 0.75mm2 (24 x 0.2mm) temperature rated to
90°C.
• Circuit breaker incorporating earth leakage protection.
• External 5A fuse to BS1362.
• The appliance must be earthed.
• This appliance must not be connected to a three phase supply.
• Wiring must comply with the latest IET wiring regulations.
• It must be possible to isolate the appliance from the electrical supply
with at least a 3mm contact separation in both poles supplying the
appliance.
• Wiring between the appliance and the electrical supply must comply
with IET wiring regulations and any local regulations that may apply
for fixed wiring to a stationary appliance.
• Any system connected to the boiler must not have a separate
electrical supply.
4.2.2 Water supply
The following are general requirements and if necessary the advice of
the local water company should be sought before fitting the appliance.
• The appliance cold water supply should be the first connection off
the water main where possible.
• The appliance will accept pre-heated hot water to a maximum of
60°C
Mains water pressure
• Maximum mains fed water pressure 10 bar. If necessary, fit a
pressure reducing valve.
• Where the water main supply has a non-return, back flow prevention
valve fitted, a mini expansion vessel (A) must be connected to the
mains water inlet pipe (B) between the non-return valve (C) and the
boiler (D) as shown in figure 3.
Fig. 3 Mains expansion vessel
[A] Mini expansion vessel
[B] Mains water inlet
[C] Non return valve
[D] Boiler
Use in hard water areas
Normally there is no need for water treatment to prevent scale formation
as the maximum temperature of the heat exchanger is limited by the
electronic control circuit.
In areas where the temporary water hardness exceeds 200ppm,
consideration may need to be given to the fitting of a scale prevention
device. In such circumstances, the advice of the local water authority
should be sought.
4.2.3 Oil supply
•This appliance is suitable for Kerosene (Class C2) only, no other
fuel must be used.
• Plastic or steel tanks should be installed to BS 5410.
A steel tank should conform to BS 799: part 5 and have a slope of
1:24 away from the outlet with a sludge cock at the lower end.
•Do not use galvanised steel tanks or pipework for the oil system.
•Do not use soldered joints on the oil supply pipework.
Salt based, softened water must not be used to fill the
central heating system.
NOTICE: Boiler damage
▶ Non-return, back flow prevention devices (including
those associated with water meters) fitted to the
mains water supply can cause a pressure build up
which could damage the boiler and other household
appliances.
Minimum dynamic mains water pressure for maximum
performance
12/18 18/25 25/32
1.5bar 1.2bar 1.6bar
NOTICE: Contaminated oil supplies can damage the
appliance.
Failure to ensure that the oil supply is clear of
contaminants may invalidate the appliance warranty.
▶ Ensure the oil supply is free of contaminates and
measures are taken to prevent contamination of the
appliance.
NOTICE: Liquid fuel supply pipes should be provided
with mains equipotential bonding in accordance with BS
7671.
A
BC
D

Pre-Installation
Greenstar Heatslave II External 2022+ 6 721 843 980 (2022/01)10
Single pipe gravity feed system
The oil storage tank [1] must be positioned so that the oil level does not
exceed 4 metres above the level of the burner oil pump [9] and in
addition the oil level must be at least 300mm above the oil pump [9].
Where the maximum oil level in the oil storage tank exceeds 4 metres, a
head breaking device must be installed between the tank [1] and the
burner oil pump [9].
Fig. 4 Single pipe feed
[1] Oil storage tank
[2] Full base (plastic tank)
[3] Isolating valve
[4] Oil strainer and water separator
[5] Fire valve to BS 5410
[6] External boiler casing
[7] Oil filter (70μm max filtration size)
[8] Fire valve sensor
[9] Oil pump
[10] Oil burner
[11] Non-return valve
[12] De-aerator
[13] Appliance isolation valve
Maximum pipe run for single pipe gravity fed system
Double pipe sub-gravity fed system
Maximum suction height 3.5 metres. Non-return valves must be fitted to
the inlet and return oil line between the oil pump [9] and oil storage tank
[1].
Fig. 5 Double pipe feed
Maximum pipe run for double pipe sub-gravity fed system
Single pipe suction lift with de-aerator
Maximum suction height 3.5 metres. The oil tank [1] must be positioned
below the oil pump [9]. Create an inlet and return loop between the de-
aerator [12] and oil pump [9].
A non-return valve must be incorporated within the de-aerator or fitted
to the oil line between the oil storage tank [1] and the de-aerator [12].
A top feed oil tank fitted with a de-aerator using an internal non-return
valve should have any non-return valves fitted in the base of the tank to
the suction line removed to assist purging air from the oil line.
Fig. 6 De-aerator feed
Maximum pipe run for single pipe suction lift with de-aerator
4.2.4 Pipework
▶ Use flexible hoses to connect to the oil pump [9].
▶ Lay the oil supply pipe as straight and level as possible to avoid air
pockets and unnecessary friction losses. Route away from the boiler
access door or other hot surfaces.
▶ Install a manual isolating valve [3] to the oil supply pipe, as close to
the oil storage tank [1] as possible.
▶ Fit an oil strainer and water separator [4] to the oil supply pipe, near
the oil storage tank. Fit an additional oil filter ([7], 70 μm max
filtration size) close to the boiler, but not inside the boiler casing.
All dimensions are in metres unless otherwise stated.
The maximum pipe run figures are based on using
copper pipe with an inside diameter of 2mm less than
the outside diameter.
Head [M] 10mmØ 12mmØ Head [M] 10mmØ 12mmØ
0.5 12 30 2.5 62 100
1.0 25 69 3.0 74 100
1.5 37 91 3.5 87 100
2.0 49 100 4.0 99 100
6720809437-41.3Wo
1
23 4
300mm Min.
4m Max.
68
53
109
13
7
1m Min.
150mm
26720809437-42.2Wo
3.5m Max.
1
3 4
73
6 8
5
11
109
1m Min.
13
Head [M] 10mmØ 12mmØ Head [M] 10mmØ 12mmØ
050100 2.0 26 66
0.5 44 100 2.5 20 50
1.0 38 95 3.0 14 37
1.5 32 80 3.5 8 22
FUEL FLOW RATE
2.5kg/h 5kg/h 10kg/h 10kg/h
Head [M] 8mmØ 8mmØ 8mmØ 10mmØ
0 100 55 26 100
0.5 95 45 23 100
1.0 80 40 20 90
1.5 70 35 17 75
2.0 60 30 14 65
2.5 45 25 11 50
3.0 35 15 8 35
3.5 25 10 5 20
The table and illustration above is a guide only and does
not in any way override the de-aerator manufacturer’s
instructions
CAUTION: Fire protection device
▶ Under no circumstances should a combination
isolating/fire valve be used as the sole fire protection
device
6720809437-43.2Wo
24
3.5m Max.
1 6
12
5
33 7
109
8
1m Min.
13