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

Pre-Installation
Greenstar Heatslave II External 2022+ - 6 721 843 980 (2022/01) 11
▶ Fit a fire valve in accordance with BS 5410. The fire valve [5] should
be fitted externally to the building and appliance with the fire valve
sensor [8] located within the appliance case. A fire valve with a shut
off temperature of 85°C or higher must be fitted to avoid the
possibility of a nuisance shut off. The fire valve must be a minimum of
1 metre from the appliance. A capillary type valve provides a neat and
simple installation, or a fusible link or electrical system may be used.
4.2.5 Boiler isolation valve
▶ Use copper pipe of the correct diameter according to the information
shown in oil supply sections , & .
– If using soft copper pipe (R220) with a compression fitting, an
insert must be used to prevent the pipe from collapsing or
distorting when the fitting is tightened.
▶ Slide nut [1] and olive [5] onto the oil supply pipe [4].
▶ Slide insert [3] into the pipe.
▶ Offer the pipe to the fitting [2] and tighten the nut [1].
Fig. 7 Isolation valve bracket removed for clarity
▶ Use flexible hoses to connect to the oil pump.
4.3 Water systems and pipework
Primary system plastic pipework
• Any plastic pipework used for the CH system must have a polymeric
barrier, complying with BS 7921 and installed to BS 5955 with
1000mm (minimum) length of copper or steel pipe connected to the
boiler.
• Plastic pipework used for underfloor heating must be correctly
controlled with a thermostatic blending valve limiting the
temperature of the circuits to approximately 50°C with 1000 mm
(minimum) length of copper or steel pipe connected to the boiler,
and a 20 K differential must be maintained at the appliance.
Primary system/connections/valves
• Do not use galvanised pipes or radiators.
• All system connections, taps and mixing valves must be capable of
sustaining a pressure of 3 bar.
• Radiator valves should conform to BS 2767:10.
• All other valves should conform to BS 1010.
• An automatic bypass valve must be connected between the heating
flow and return where TRVs are used on all radiators, fitted to give at
least a 3 metre circuit when activated.
• Drain cocks are required at all the lowest points on the system.
• Air vents are required at all high points on the system.
Sealed primary system
• Where the system volume is more than 180 litres at 0.5 bar or
exceeds 2.65 bar at maximum heating temperature an extra
expansion vessel (B) must be fitted as close as possible to the
appliance in the central heating return.
• Pressurise the extra expansion vessel (B) to the same figure as the
expansion vessel (A) built into the appliance.
Fig. 8 Combi boiler sealed system layout
[A] Expansion vessel
[B] Extra expansion vessel
[C] Automatic bypass valve
[D] Drain cock
[E] Appliance
[L] Lockshield valve
[R] Radiators
[T] Thermostatic radiator valve TRV
[U] To filling system
Filling primary sealed systems
• Filling the system must comply with the method shown in the figure
below.
• The filling point must be at low level and must never be a permanent
connection to the mains water supply.
• Filling loops must be WRAS approved.
Fig. 9
[CV] Check valve
[SV] Stop valve
The boiler should not be allowed to operate with a return
temperature of less than 30°C when the system is up to
operating temperature.
Oil burners cannot modulate to accommodate a
reduction in heating loads. If the heating load can be
significantly reduced due to TRV’s or zoning of the
heating circuits, consideration should be given as to how
short cycling of the burner could be prevented. Burner
run times should remain greater than 2 minutes during
normal operation. A buffer vessel or thermal store
should be considered to prevent excessive short cycling
of a single appliance, or a low loss header could be used
to divide the heating duty between multiple lower output
appliances.
6720813288-03.1Wo
1
5
4
3
2
Filling the system
▶ The system must not be filled with salt based,
softened water.
D
R R
R R
B
P
D
C
TLTL
TL LL
A
U
E
6720805209-82.1Wo
SYSTEM FILL
SV SV
Test point
Temporary hose
Hose union CV
CV
Heating
return
Mains
supply

Pre-Installation
Greenstar Heatslave II External 2022+ 6 721 843 980 (2022/01)12
Fig. 10
Showers/Bidets:
• If a shower head can be immersed in water or comes closer than
25mm from the top edge of a bath or shower tray spill over level then
an anti-siphon device must be fitted to the shower hose.
Only thermostatically controlled showers are suitable for use with
this appliance.
• Bidets with direct hot & cold mains water can be used (with the
approval of the local water authority) and must be the over rim
flushing type with shrouded outlets to prevent the fitting of hand held
sprays.
Domestic hot water:
Plastic pipework
• Any plastic pipework used for the DHW system must have a
polymeric barrier, complying with BS 7921 and installed to BS 5955
with 1000mm (minimum) length of copper or stainless steel pipe
connected to the boiler.
• Before installing plastic pipework, the pipe manufacturer’s literature
should be consulted.
• To prevent the temperature & pressure exceeding the limits advised
by the pipe manufacturer, a pressure reducing valve must be used to
prevent the incoming water pressure exceeding 3 bar (maximum).
Also a mini expansion vessel must be fitted to absorb the expanding
water and a blending valve set to 60°C must be fitted before the DHW
plastic pipework.
• When selecting plastic pipework for use with domestic water supply,
it should be ensured that it is compliant with all current local &
national legislation & regulations, including building regulations part
G, BS 7291 - 1,2 & 3: BS 8000 - 15 and information.
General:
• Taps and mixing valves must be capable of sustaining a pressure up
to 10 bar in accordance with the Water Regulations as they will be
operating at mains water pressure.
• Hot water temperature and flow rate are affected by the size and
insulation of pipework making up the distribution system and are
controlled by the hot water tap and the water main inlet pressure. A
mixing valve can be fitted if a more permanent setting is required.
• If using more than one outlet at once causes water flow starvation, fit
flow balancing valves or Ball-O-Fix valves to the appropriate outlets.
4.4 Condensate pipework
Externally run condensate drainage pipe should terminate at a suitable
foul water discharge point, or purpose-designed soak away. If this
method is chosen then the following measures should be adopted:
▶ The external run be kept as short as possible and not exceed three
metres.
▶ The pipe diameter should be increased to 32mm and should be
insulated using suitable waterproof and weather resistant insulation.
▶ The external pipe should take the shortest and least exposed route to
the discharge point, and should "fall" as steeply as possible away
from the boiler, with no horizontal runs in which condensate might
stand.
▶ The use of fittings, elbows etc. should be kept to a minimum and any
internal “burrs” on cut pipe work should be removed so that the
internal pipe section is as smooth as possible.
4.4.1 Condensate disposal connections
Greenstar Heatslave II
external oil fired
combination boiler
Hot water supply
to property
Mini expansion
vessel
(0.75ltr capacity)
Balanced cold water
supply to property
3 bar pressure
reducing
valve
MCW
Check valve/
non return valve
Incoming
mains
stop valve
Blending valve
set to 60°C
6720805210-20.1Wo
NOTICE: Rainwater or external drain disposal
Untreated condensate must not be allowed to flow into
streams or rivers
▶ A rainwater down pipe or an external drain shall only
be used for condensate disposal if the down pipe or
external drain is connected to a combined foul and
rainwater system
▶ Refer to BS 6798 for more information
NOTICE: Grey water systems
Contamination of recovered water
▶ Condensate disposal shall not be allowed into a grey
water recovery system that is intended for re-use
▶ The condensate pipe must be nominally
21.5mm Ø Polypropylene pipe.
▶ The condensate pipe work must fall at least 52mm
per metre towards the outlet and should take the
shortest practicable route.
▶ Ensure there are no blockages in the pipe run.
Condensate drainage pipe can be run above or below
ground.
Key to condensate illustrations
1 Condensate discharge from boiler
2 Universal connector
3 Soil and vent stack
4 Minimum 450mm and up to three storeys
5 Pipe work transition
6 Insulate and increase pipe size
7 External rain water pipe into foul water
8Externalairbreak
9 43mm pipe (min 100mm upstand)
10 PVCu strap on fitting
11 43mm 90° male/female bend
* Condensate trap of 75mm already incorporated into the boiler

Pre-Installation
Greenstar Heatslave II External 2022+ - 6 721 843 980 (2022/01) 13
Fig. 11 Disposal to a soil vent stack
Fitting an external air break
• Refer to figure 12 when a rain water down pipe is used to dispose of
condensate.
• An air break must be installed in the 43mm pipe work, between the
boiler condensate outlet and the drainpipe, outside the property, to
avoid flooding during adverse weather conditions.
Fig. 12 Disposal into a rainwater down pipe
Where the pipe terminates over an open drain or gully, the pipe should
terminate below the grating level, but above water level, in order to
minimise “wind chill” at the open end.
The use of a drain cover (such as those used to prevent blockage by
leaves) may offer further protection from wind chill.
Pipe drainage will be improved if the end is cut at 45° as opposed to a
straight cut.
Fig. 13 External drain
4.4.2 Soak away
• The condensate drainage pipe may be run above or below the ground
to the soak away. The examples shown on this page run above
ground.
• The soak away must use a 100mm Ø plastic tube with two rows of
three 12mm holes on 25mm centres and 50mm from the bottom of
the tube. The holes must face away from the house.
• The tube must be surrounded by at least 100mm of limestone
chippings to a depth of 400mm.
In situations where there are likely to be extremes of temperature or
exposure, the use of a proprietary trace-heating system for external pipe
work, incorporating an external frost thermostat, should be considered.
If such a system is used, the requirement to use 32mm pipe does not
apply. However, all other guidance above and the instructions for the
trace heating system, should be closely followed.
Fig. 14 Disposal to a soakaway
Condensate waste
▶ Care should be taken when siting a soak-away to
avoid obstructing existing services.
6720809437-03.1Wo
3
5
6
4
2
1
21.5mm Ø
6720809437-04.1Wo
5
6
2
1
7
8
10
9
11
21.5mm Ø
25mm min.
6720809437-05.1Wo
5
2
1
6
21.5mm Ø
Minimum hole size for the condensate soak away mustbe
400mm deep by 300mmØ .
Key to condensate soakaway
1 Condensate discharge from boiler
2 Push fit connector
5 Pipe work transition
6 Insulate and increase pipe size
12 100mm Ø minimum plastic pipe
13 Drainage holes
14 Limestone chippings (25kg min.)
15 Bottom of sealed tube
* Condensate trap of 75mm already incorporated into the boiler
25mm min.
500mm min.
Unsuitable for clay soil types.
400mm min.
12
13
6720809437-06.1Wo
5
2
1
6
21.5mm Ø
15
13
14
12

Pre-Installation
Greenstar Heatslave II External 2022+ 6 721 843 980 (2022/01)14
4.5 Pressure relief pipework
• The pressure relief discharge pipe [2]should be at least 15mm
diameter copper pipe and run downwards away from the boiler and
discharge away from any electrical or other hazard, preferably to an
external drain or soakaway.
• Pipe [2] should be finished with a partial bend, near the outlet to
prevent discharge onto entrances or other public access where it
could cause a hazard.
Fig. 15 Pressure relief pipe work
[1] External casing
[2] PRV discharge pipe
[3] Hardstanding
4.6 Boiler locations and clearances
Clearances:
▶ Minimum service and flue clearances.
– Above - 600mm
– Front - 600mm
– RH clearance flue outlet on rear - 300mm
– LH clearance flue outlet on rear - 10mm
– Rear clearance flue outlet on side - 50mm
– Rear clearance flue outlet on rear 2500mm
It is strongly recommended that the flue terminal faces away from
walls to reduce the possibility of wetting occurring.
Fig. 16 Above clearance
Fig. 17 Rear exit flue clearances
Fig. 18 Left exit flue clearances
Fig. 19 Right exit flue clearances
WARNING: This appliance should not be installed where
there is a potential for excessive ground water coverage.
This boiler is only suitable for installing externally at a
suitable location onto a fixed permanent, non-
combustible, rigid surface capable of supporting the
boiler weight.
There must be a sufficient hard standing around the
appliance to allow for servicing.
The boiler must be installed on a flat level surface to
ensure that condensate does not enter the primary heat
exchanger.
Tarmac and wood hard-standings are not
recommended.
6720809437-07.1Wo
3
2
2
3
1
1
6720809437-08.1Wo
600mm
2500mm
600mm
BASE
FRONT
600mm min
6720821722-03.1Wo
FRONT
300mm
600mm Plan
view
2500mm
10mm
6720809437-10.2Wo
50mm
10mm
600mm
2500mm
FRONT
Plan
view
6720809437-11.2Wo
FRONT
2500mm
10mm
600mm
50mm
Plan
view

Pre-Installation
Greenstar Heatslave II External 2022+ - 6 721 843 980 (2022/01) 15
4.7 Flue gas system considerations
Room air dependant operation
The boiler primarily operates as a “room air sealed” unit, however the
boiler can be operated as a “room air dependant” unit, if required.
Provide sufficient boiler room ventilation when operating the appliance
room air dependent.
▶ Do not obstruct or block any ventilation openings.
▶ Ventilation openings must always be kept clear.
4.7.1 Combustion air quality
To avoid corrosion, combustion air must be free from aggressive
substances (e.g. hydrogen halide, chlorines and fluorine).
4.7.2 Flue terminal positions
• Flue terminals must be positioned to avoid combustion products
entering into buildings.
• The flue must be fitted and terminated in accordance with the
recommendations of the latest version of BS 5410:1.
• The flue must not cause an obstruction.
• Discharge from the flue outlet must not cause a nuisance or dispute.
• Flue gases have a tendency to plume and in certain weather
conditions a white plume of condensation will be discharged from the
flue outlet which could be regarded as a nuisance, for example, near
security lighting.
• There should be no restriction preventing the clearance of
combustion products from the terminal.
• The air inlet/outlet duct and the terminal of the boiler must not be
closer than 25mm to any combustible material. Detailed
recommendations on protection of combustible materials are given
in the latest version of BS 5410:1.
• Where a vertical flue terminates in an area thatis enclosed on 3 sides,
the flue must be no more than 1,000mm below the lowest roof line.
You must ensure that all clearances are maintained and that products
of combustion disperse safely from the area.
• Dimensions from a flue terminal to a fanned air inlet to be determined
by the ventilation equipment manufacturer.
• A protective stainless steel terminal guard, must be fitted if the
terminal is 2 metres or less, above a surface where people have
access.
• See “Contact Information” on the back cover for flue guard
information.
• Avoid discharging flue gases into car ports or narrow passageways.
CAUTION: Non accessible flue systems:
▶ Where a flue system is not going to be accessible,
provision must be made for service and inspection.
▶ Flue gas system must comply with local standards
and regulations.
NOTICE: Damage to appliance from contaminated
combustion air and contaminated air in the vicinity of
the appliance!
▶ Never operate the boiler in a dusty chemically
aggressive environment i.e. spray painting, hair
dressing and farming facilities.
▶ Never operate the boiler in places where using or
storing trichlorethane, hydrogen halide and other
aggressive chemical substances. These substances
can be contained in spray cans, various glues,
primers, paints and cleaning substances.
In this case, the appliance must be connected in a
room sealed configuration.
All measurements are the minimum clearances required

Pre-Installation
Greenstar Heatslave II External 2022+ 6 721 843 980 (2022/01)16
Fig. 20 Flue terminal positions
BOUNDARY LINE
600
600
600
2000 1500
RIDGE FLUERIDGE VENT
1500
1500
600
400
1500
600
1500
1000 75
100
75
100
BOUNDARIES
1/2
1/2
100
75
100
1000
300
1000
300
1000 300
75
100
300
75
BOUNDARY LINE
2500
2000
OPENING
OPPOSITE
TOP
300
TOP
SKYLIGHTDORMA
100
1500 1500
100
1000300
600
750 750
2000
1500
BOUNDARY LINE
300
300
TOP
45°
2500
600
600
EXCLUSION ZONE
14
12232
4
5
1
17
16
11
10
7
13
8
9
9
15
18
2
2
12
12
12
4
15
14
18
18
21
19
6
20
16
15 15
27
22
21
21
25
18
23
24
26
750
600 750
750
1200
300 1500
1500
400
600
2500
1800
2500
1200
1500
1000
1000
1000
1000
750
1000
300
1000
1000
300
300
300
300
1500
0010023942-002

Pre-Installation
Greenstar Heatslave II External 2022+ - 6 721 843 980 (2022/01) 17
Key to illustration 20:
1. 1,500mm measured between an opening or vented window and
vertical flue terminal.This measurement can be reduced to 1000mm
providing the flue terminal is at least 300mm above the opening.
2. Minimum clearance to an additional flue, 1,500mm between room
sealed flues or room sealed flue and open flue, 1,000mm between
open flues.
3. 600mm above a vertical structure less than 750mm from the side of
the terminal.
4. The flue must extend at least 600mm above the intersection of the
roof (flat and pitched) and be 400mm horizontally from a pitched
roof or 500mm in regions with heavy snow fall
5. The flue must not penetrate the roof in the shaded area. The flue must
be at least 2,000mm from the opening or vent when sited below the
window,600mm when sited to either side or above.The terminal
must be at least 1,500mm room sealed, 1,000mm open flue from
the opening or vent when measured horizontally.
6. The flue must not penetrate the roof in the shaded area. The flue must
be at least 1,000mm from the opening or vent when sited below the
window, 750mm when sited to either side and 300mm above.The
terminal must be at least 1,500mm from the opening or vent when
measured horizontally.
7. 300mm minimum clearance measured from a non opening skylight
to a vertical flue.Vertical flue clearance,
8. 600mm minimum clearance measured from an opening or vented
skylight to a vertical flue. If the terminal is within 1,500mm of the
opening or vented skylight then it must be at least 600mm above the
opening.
9. 750mm clearance to a structure from a vertical flue.
Not required if the terminal is 600mm above the structure.
10. 750mm adjacent to a boundary line unless it will cause a nuisance.
BS 5410: Part 1 recommended that care is taken when siting
terminal in relation to boundary lines.
11. 1,200mm separation measured between a vertical flue and a
horizontal flue terminal. Not required if the horizontal flue is
1,500mm above vertical flue terminal.
12. 1,000mm (BS 5410-1) above, below and either side of an opening
door, air vent or opening window. These clearances are required by
BS 5410 Part 1 to reduce a possible pluming nuisance.If 1,000mm
cannot be achieved then the distance can be reduced to 600mm to
comply with Approved Document J of the building regulations if it
will not cause a nuisance or dispute.
13. 300mm adjacent to a boundary line unless it will cause a nuisance.
BS 5410: Part 1 recommended that care is taken when siting
terminal in relation to boundary lines.
14. 1,500mm vertically between terminals and the same wall.
15. 1,000mm (BS 5410-1) below eaves, gutters and sanitary pipe and
300mm from vertical sanitary pipes and drains.
If 1,000mm cannot be achieved then the distance below eaves,
gutters and sanitary pipe can be reduced to comply with Approved
Document J of the building regulations if it will not cause a nuisance
or dispute. 75mm if combustible material is protected or 600mm
without protection to combustible material1).
16. The dimension below eaves, gutters, pipes and drains can be
reduced to 75mm, as long as the flue terminal is extended by
100mm past any overhang. The telescopic flue joint must be sealed
with suitable silicone sealant if it is external to the building
17. 1,200mm between terminals facing each other.
18. 2,500mm (BS 5410-1) distance to a surface or boundary line.
If 2,500mm cannot be achieved then the distance can be reduced
to 600mm to comply with Approved Document J of the building
regulations if it will not cause a nuisance or dispute.
19. Terminals must be at least 1,800mm from an oil storage tank
unless a wall with of at least 30 minutes fire resistance and
extending 300mm wider and higher than the tank is between the
tank and the terminal. The flue air intake must be at least 900mm
away from the oil storage tank vent.
20. 1000mm diagonally to an opening door, air vent or opening
window.
21. 300mm to an internal or external corner. 300mm above a surface,
such as the ground/ floor level or roof surface.
22. The dimension below eaves, balconies and car ports can be
reduced to 75mm, as long as the flue terminal is extended to clear
any overhang. The telescopic flue joint of the terminal must be
sealed with suitable silicon sealant if it is external to the building.
23. 1,000mm (BS 5410-1) from an opening or vented window,
300mm to a fixed unvented window. If 1,000mm cannot be
achieved then the distance from an opening or vented window can
be reduced to 600mm to comply with Approved Document J of the
building regulations if it will not cause a nuisance or dispute.
24. The flue terminal must be at least 1,500mm from the opening or
vented skylight when sited below the opening or vented skylight.
25. Proximity of flue duct outlet to boundaries, 2000mm distance to an
opening in adjacent building facing a terminal. BS 5410: Part 1
recommended that care is taken when siting terminal in relation to
boundary lines.
26. The distance between a boundary facing a flue terminal can be
measured diagonally from the point of discharge with a minimum
distance of 600mm which must be maintained. The exclusion zone
ensures compliance with Approved Document J of the building
regulations.
27. For the purpose of determining suitable flue terminal positions for
oil appliances discharging over public boundaries, the boundary
can be considered to extend to the centre line of any adjacent
routes or waterways e.g. paths, streets, rights of way, canals, rivers
or railways.
NOTICE:
▶ All measurements are the minimum clearances
required.
▶ Terminals must be positioned so to avoid
combustion products entering the building.
▶ Support the flue at approximately one metre
intervals and at a change of direction, use suitable
brackets and fittings:
- flue bracket 125mm x 1- Part No.: 7 716 191 179
▶ In spite of the dimensions given here, the terminal
must not be closer than 300mm to combustible
material, in the case of a thatched roof double this
dimension.
▶ Terminals must be positioned so to avoid products
of combustion accumulating in stagnant pockets
around the building or entering the building.
▶ Terminals must be at least 1.8m from an oil storage
tank unless a wall with of at least 30 minutes fire
resistance and extending 300mm wider and higher
than the tank is between the tank and the terminal.
1) A way of providing protection of combustible material would be to fit a heat
shield at least 750mm wide.
NOTICE:
▶ Installations in car ports are not recommended.
▶ Dimensions from a flue terminal to a fanned air inlet
to be determined by the ventilation equipment
manufacturer.

Pre-Installation
Greenstar Heatslave II External 2022+ 6 721 843 980 (2022/01)18
4.8 Flue options
4.8.1 Cabinet mounted balanced horizontal flue options
• The horizontal flue is fitted to the rear or either side of the cabinet.
Fig. 21 Flue options
4.8.2 Plume management
1. Measure the plume management flue (M) from the centre of terminal,
along the required route to the centre of the plume outlet.
Fitting the terminal plume management kit
1. Remove and retain the screws that secure the terminal end into the
flue.
2. Discard the terminal end.
3. Fit the terminal elbow into the flue but do not secure with the screws
until the plume management system has been assembled.
Fig. 22 Fitting the terminal bend
1. Connect the sections of the plume management for desired length.
– Screw the clamp into the wall.
– Push the extension/s tube fully into the 90° bend, then withdraw
the tube by approximately 10mm to allow for expansion.
2. Once the plume management system is in place and secured to the
wall, secure the terminal bend with the screws removed earlier.
▶ The terminal end can be positioned up to 45° either side of the
central position, for plume re-direction.
▶ Adjust the plume management terminal end into the desired position
and secure with the screws provided.
Fig. 23 Plume management detail
It is strongly recommended that the flue terminal faces
away from walls to minimise the occurrence of wetting.
Heatslave II Flue length (L) Plume length (M)
12/18 & 18/25 160 - 2000mm 500 - 5000mm
Bends maximum of 2 maximum of 2
25/32 160 - 2000mm 500 - 4000mm
Bends maximum of 2 maximum of 2
Effective lengths of elbows
Bend Flue Plume
90° 1000mm 1000mm
45° 500mm 500mm
Table 4 Effective lengths of bends
6720809437-12.1Wo
FRONT
Plan
View
FRONT
Plan
View
FRONT
Plan
View
REAR FLUE OUTLET
LEFT HAND FLUE OUTLET
RIGHT HAND FLUE OUTLET
2.
3.
6720645523-50.1Wo
1.
1.
6720645523 51 2 W
1.
2.
±45°
Min. 150mm
M
Min, 250mm to any
wall or obstruction

Pre-Installation
Greenstar Heatslave II External 2022+ - 6 721 843 980 (2022/01) 19
4.8.3 Plume management considerations
Fig. 24 Plume terminal positions
KEY TO ILLUSTRATION
1. Plume Management kit air intake can be reduced to 150mm
providing the flue exhaust outlet is no less than 300mm adjacent to
a boundary line.
2. 1,200mm between the terminals on opposing walls. Where two
plume management kits are used 1200mm must be maintained
between both opposing terminals and air inlets. Each terminal
should use a minimum length of 500mm plume management
3. Below balcony or overhang. The air intake clearance can be
reduced to 150mm providing the flue exhaust outlet has a
1000mm clearance in BS 5410-1.
4. 300mm distance from a boundary line to the air intake as long as
the exhaust terminal faces away from the boundary line. The
exhaust terminal must have a minimum 300mm clearance to a
surface below and there must be at least 2,500mm (BS 5410- 1)
clearance when measured horizontally in a straight line from the
exhaust outlet to any other surface. If 2,500mm cannot be
achieved then the flue exhaust outlet distance can be reduced to
600mm to comply with Approved Document J of the building
regulations if it will not cause a nuisance or dispute.
5. 2,500mm (BS 5410-1) distance to a surface or boundary line. If
2,500mm cannot be achieved then the distance can be reduced to
600mm to comply with Approved Document J of the building
regulations if it will not cause a nuisance or dispute.
6. Terminals must be at least 1,800mm from an oil storage tank
unless a wall with of at least 30 minutes fire resistance and
extending 300mm wider and higher than the tank is between the
tank and the terminal. The flue air intake must be at least 900mm
away from the oil storage tank vent.
7. 300mm adjacent to a boundary line unless it will cause a nuisance.
BS 5410: Part 1 recommended that care is taken when siting
terminal in relation to boundary lines.
8. Above, below and either side of an opening door, air vent or
opening window. Using a Plume Management kit the air intake
measurement can be reduced to 150mm providing the flue
exhaust outlet has a 1,000mm (BS 5410-1) clearance. If
1,000mmcannot beachieved then theflue exhaustoutlet distance
can be reduced to 600mm to comply with Approved Document J of
the building regulations if it will not cause a nuisance or dispute.
9. Internal/external corners. The air intake clearance can be reduced
to 150mm providing the flue exhaust outlet has a 300mm
clearance.
10. Vertical sanitary pipe: 150mm to the flue air intake and 300mm to
the flue exhaust outlet.
11. Proximity of flue duct outlet to boundaries, minimum 2,000mm
distance to an opening in adjacent building facing a terminal. BS
5410: Part 1 recommended that care is taken when siting terminal
in relation to boundary lines.
BOUNDARY LINE
1200
150 150 150
150
150
300
150
300
1000
200
200
300
1000
2500
300
1000
300
2500
300
300
300
2500
1800
100
≥140
≥50
0
EXCLUSION ZONE A
100
≥5
00
EXCLUSION ZONE A
2500
2500
5
0
0
5
0
0
5
0
0
±80°
EXCLUSION ZONE A
±45°
BOUNDARY LINE
2500
2000
OPENING
OPPOSITE
300
300
300
150
TOP
TOP
FLUE TERMINAL GUARD
7 716 191 176
1000
150
BOUNDARY LINE
BOUNDARY LINE
300
300
TOP
2500
2500
600
600
EXCLUSION ZONE
150
TOP
EXCLUSION ZONE
600
600
45°
45°
6
5
5
5
7
4
2
1
3
74
1
1
13
5
10
9
8
8
8
5
5
11
12
12
0010023943-001
NOTICE:
▶ All measurements are the minimum clearances
required.
▶ Terminals must be positioned so to avoid combustion
products entering the building.
▶ Support the flue at approximatelyone metre intervals
and at a change of direction, use suitable brackets
and fittings.

Pre-Installation
Greenstar Heatslave II External 2022+ 6 721 843 980 (2022/01)20
12. The distance between a boundary facing a terminal can be
measured diagonally from the point of discharge with a minimum
distance of 600mm which must be maintained. The exclusion zone
ensures compliance with Approved Document J of the building
regulations,
13. A plume management kit must not be terminated within the
confines of a carport or other covered, partially enclosed
extension. The exhaust terminal must be sited at least 300 mm
beyond the footprint of the structure, and maintain a distance of at
least 600mm to any opening sited within the confines of the
structure.
The exhaust terminal can also be routed though the roof of the
carport providing 25mm clearance is provided around the flue pipe
to any flammable material and that it extends at least 300mm
above the roof. The air intake must have a minimum 150mm
clearance to any opening in the building in order to ensure the
integrity of the structure is maintained. If the air intake is sited
within the footprint of the carport then the carport must have at
least one completely open side.
▶ The flue cannot be lower than 1,000mm from the top
of a light well due to the build up of combustion
products.
▶ Plume kits running horizontally must have at least a 3°
fall back to the appliance for proper disposal of
condensate. The initial plume kit horizontal run will
have at least a 10° fall back to the appliance, due to
the terminal elbow design, for proper disposal of the
condensate.