British Gas ICC2 combi ZWBR 11-37 ICC2 User guide

Installation and Servicing Instructions
ICC2 combi
Wall mounted condensing boiler for central heating and mains
fed domestic hot water
6 720 610 598-00.1
O
ZWBR 8-3 ICC2 GC-Number: 41 108 09
ZWBR 11-37 ICC2
GC-Number: 41 108 10
6 720 610 602 GB (03.02) OSW

6 720 610 602 GB (03.02)
2
Contents
Contents
Safety precautions 3
Symbols 3
1 Details of the appliance 4
1.1 EC Declaration of Conformity 4
1.2 Standard package 4
1.3 Description of appliance 4
1.4 Accessories 5
1.5 Casing dimensions 5
1.6 Layo t of appliance 6
1.7 F nction 7
1.8 Electrical wiring diagram 8
1.9 Technical data 9
2 Installation regulations 10
3 Installation 11
3.1 Important remarks 11
3.2 Domestic hot water 11
3.3 Sealed systems 11
3.4 Siting the appliance 12
3.5 Wall mo nting frame assembly 13
3.6 Pre-piping the system 13
3.7 Fitting the appliance 14
3.8 Checking the connections 15
3.9 Fl e Systems 15
3.9.1 Siting the Fl e Terminal 16
3.9.2 Installation of the fl e 17
3.9.3 Fl e d ct preparation and assembly 19
4 Electrical connections 20
4.1 Connecting the appliance 20
4.2 Connecting TR2 Room thermostat 21
4.3 Mains Voltage external controls connections 21
5 Commissioning 22
5.1 Commissioning 22
5.2 Switching the appliance on/off 23
5.3 Switching on the central heating 23
5.4 System controls 23
5.5 Setting the domestic hot water
temperat re and flow rate 24
5.5.1 Domestic hot water temperat re 24
5.5.2 Hot water flow rate 24
5.6 S mmer mode (hot water only) 24
5.7 Frost protection 24
5.8 P mp anti-seize f nction 24
5.9 Fa lt Condition 25
6 ext Display 26
6.1 General Description 26
6.2 Programming 26
6.2.1 Deleting a setting 27
6.2.2 Resetting all parameters to their
original settings 27
6.3 Men str ct re 27
6.4 Setting the time/day 28
6.4.1 Setting the time and day 28
6.4.2 Holidays 28
6.5 Heating 28
6.5.1 Heating programme 28
6.5.2 Setting the Economy temperat re
(if TR2 is connected) 28
6.5.3 Man al operating mode
(if TR2 is not connected) 29
6.6 Hot water 29
6.6.1 Hot water programme 29
6.6.2 Hot water immediately 29
6.7 i Info 29
6.8 Settings 30
6.8.1 Heating (if TR 2 is connected) 30
6.8.2 Hot Water (Storage Tank,
ZSBR models only) 30
6.8.3 Service 30
6.9 Individ al timer programmes 30
7 Individual settings 31
7.1 Mechanical settings 31
7.1.1 Checking the size of the expansion vessel 31
7.1.2 Setting the central heating flow temperat re 31
7.2 Settings on the Bosch Heatronic 31
7.2.1 General description 31
7.2.2 Setting the anti-cycle time
(Service F nction 2.4) 32
7.2.3 Setting the maxim m CH flow temperat re
(Service F nction 2.5) 32
7.2.4 Setting the heating o tp t
(Service F nction 5.0) 32
7.2.5 Constant hot water cycle time
(Service F nction 6.8) 32
7.2.6 Variable p mp settings
(Service F nction 7.0) 32
7.3 Setting the gas/air ratio 32
8 Converting the appliance to different
gas types 33
8.1 Setting the gas/air ratio 33
8.2 Testing comb stion air/fl e gas at set
heat o tp t 35
8.2.1 Testing the O
2
or CO
2
level
in the comb stion air 35
8.2.2 Testing CO and CO
2
35
9 Maintenance 36
9.1 Pre-Service Check List 37
9.2 Description of servicing operations 38
9.3 Replacement of Parts 41
9.3.1 PCB control board and transformer 41
9.3.2 Fan Assembly 42
9.3.3 P mp 42
9.3.4 3-way diverter valve 43
9.3.5 3-way diverter valve motor 43
9.3.6 Sensors 43
9.3.7 Gas Valve 44
9.3.8 Domestic Hot Water Heat Exchanger 44
9.3.9 Electrode assembly 44
9.3.10Press re ga ge 44
9.3.11Expansion vessel 44
9.3.12Press re Relief Valve 44
9.3.13B rner 44
9.3.14Flow switch 45
9.3.15Primary Heat Exchanger 45
10 Appendix 46
10.1 Fa lt Codes 46
10.2 Short parts list 47
10.3 Heating/hot water o tp t settings
ZWBR 8-30 N.G. 48
10.4 Heating/hot water o tp t settings
ZWBR 11-30 L.P.G 48
10.5 Heating/hot water o tp t settings
ZWBR 11-37 N.G. 48
10.6 Heating/hot water o tp t settings
ZWBR 14-37 L.P.G 48
10.7 Operational Flow diagrams 49
10.7.1Domestic hot water f nction 49
10.7.2Central heating f nction 50

6 720 610 602 GB (03.02)
Safety precautions
3
Safety precautions
If you smell gas
B Turn off as service cock at the meter.
B Open windows and doors.
B Do not operate any electrical switches.
B Extin uish any naked flames.
B Telephone your as company.
If you smell fumes from the appliance
B Switch off appliance (see pa e 23).
B Open windows and doors.
Fitting and modifications
B Fittin of the appliance or any controls to the appli-
ance may only be carried out by a competent en i-
neer in accordance wth the Gas Safety (Installation
and Use) Re ulations 1998.
B Flue systems must not be modified in any ways other
than as described in the fittin instructions.
B This appliance is for use on sealed primary systems only.
Maintenance
B The user is recommended: to have the system
re ularly serviced in order to ensure that it functions
reliably and safely.
B Use only ori inal spare parts!
Combustible materials
B Do not store or use any combustible materials
(paper, thinners, paints etc.) in the vicinity of the
appliance.
Health and safety
B This appliance contains no asbestos products.
B There is no potential hazard due to the appliance
bein electrically unsafe.
B There are no substances used in the construction
that are a potential hazard in relation to the COSHH
Re ulations (Control of Substances Hazardous to
Health Re ulations 1988).
Combustion air/Ambient atmosphere
B The combustion air/ambient atmosphere should be
kept free of chemically a ressive substances (e. .
halo enated hydrocarbons which contain chlorine or
fluorine compounds). This will prevent corrosion.
Instructions to the customer
B Explain to the customer how the appliance works
and how to operate it.
B Advise the user that he/she must not make any modi-
fications to the appliance or carry out any repairs on it.
B These instructions are to be left with the user or at
the Gas meter.
B Important: These instructions apply in the UK only.
Symbols
Safety instructions in this doc ment
are identified by a warning-triangle sym-
bol and are printed on a grey back-
gro nd.
i
Notes containing important information
are identified by the symbol shown on the
left. They are bordered by horizontal lines
above and below the text.

6 720 610 602 GB (03.02)
4
Details of the appliance
1 Details of the appliance
1.1 EC Declaration of Conformity
This appliance is in accordance with the applicable
requirements of the Gas Appliance Directive, Boiler
Efficiency Directive, Electroma netic Compatibility
Directive and the Low Volta e Directive.
1.2 Standard package
• Gas condensin combination boiler for central heat-
in and domestic hot water
• Control panel cover
• Wall mountin frame
• Room thermostat TR2
• Clamp for securin flue duct kit
• Fixin s (screws etc.)
• Set of documentation for appliance
• Pre-plumbin manifold
• Condensate drain pipe
• Fillin loop.
1.3 Description of appliance
• Wall-mounted appliance, sitin not dependent on
room size
• Natural as models are low-emission appliances
• Multifunction display
• Bosch Heatronic control system with inte rated tex-
tdisplay for servicefunctions and faults
• 3-channel - di ital timer for one heatin circuit
• Variable pump
• Automatic i nition
• Modulatin control
• Full safety systems incorporatin Bosch Heatronic
with flame ionisation monitorin , solenoid valves and
temperature sensors
• Concentric flue/air duct with testin point for
CO
2
/CO
• Re ulated speed fan
• Pre-mix burner
• Temperature control for central heatin
• Temperature sensor in domestic hot water
• Safety temperature limiter in 24 V electrical circuit
• Relief valve, pressure au e, expansion vessel
• Flue as temperature limiter (105 °C)
• Hot water priority circuit
• Motorised 3-way valve
• Plate-type heat exchan e
• Condensate Trap.
PIN CE-0085 BL0507
Category UK II
2H 3P
Appliance Type C
13
, C
33
Table 1

6 720 610 602 GB (03.02)
Details of the appliance
5
1.4 Accessories
• Standard horizontal flue kit at 100 mm outside
diameter for flues upto 4 m in len th.
• Flue duct kits for horizontal (125 mm outside
diameter) for flue len ths upto 10 m (ZWBR 11-37)
or 13 m (ZWBR 8-30) and vertical flue systems for
flue len ths 12 m (ZWBR 11-37) or 15m (ZWBR 8-
30). Fittin instructions are sent with these kits.
• Heatin pro rammer,
• Security kit.
1.5 Casing dimensions
Fig. 1
13 Manifold assembly
1 1 Outer case
1 3 Facia cover
X Standard Concentric Horizontal Flue System: min. 310 mm
Alternative Concentric Flue System: min. 250 mm
Y Standard Concentric Horizontal Flue System: 158 mm
Alternative Concentric Flue System: 121 mm
Z Standard Concentric Horizontal Flue System: 105 mm
Alternative Concentric Flue System: 130 mm
*
For servicin the appliance
min.
5
min.
5
512
850
101
103
6 720 610 602 - 01.3O
200
30
13
395
360
861
906
35
X
120
Y
Z
200
**
*
*
600

6 720 610 602 GB (03.02)
6
Details of the appliance
1.6 Layout of appliance
Fig. 2
4Heatronic control
6Heat exchan er safety temperature limiter
6.1 Hot water NTC sensor
7Testin point for as supply pressure
8.1 Pressure au e
9Flue as temperature limiter
15 Relief valve
18 Pump
2 Expansion vessel
27 Automatic air vent
29 Air as Mixer unit
32.1 Electrode assembly
36 Temperature sensor in CH flow
43 CH flow
63 Adjustable as flow restrictor
64 Adjustin screw for min. as flow volume
88 3-way valve (combi)
98 DHW flow switch (combi)
1 2 Inspection window
12 Fixin points
221.1 Flue duct
221.2 Combustion air intake
226 Fan assembly
295 Appliance type sticker
234 Testin point for combustion products
234.1 Testin point for combustion air
271 Flue duct
349 Cover plate for twin flue duct connection
355 Plate-type domestic hot water heat exchan er
358 Condensate trap
396 Hose Condensate trap
4 Textdisplay
415 Cover plate for cleanin access
416 Condensate collector
418 Data plate
423 Siphon
29
98
102
226
234.1
271
416
221.1
221.2
20
43
9
63
358
64
7
355
6.1
4
415
6
36
32.1
234
349
295
8.1
18
27
88
15
120
418
400
396
423
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6 720 610 602 GB (03.02)
Details of the appliance
7
1.7 Function
Fig. 3
4Bosch Heatronic control
6Temperature limiter, heat exchan er
6.1 Hot water NTC sensor
7Testin point for as supply pressure
8.1 Pressure au e
9Flue as temperature limiter
13 Manifold
15 Safety valve
18 Central heatin pump
2 Expansion vessel
26 Char in valve
27 Automatic vent
29 Mixer unit
29.1 Bi-metallic thermostat for combustion air compensation
3 Burner
32 Flame sensin electrode
33 I niter electrode
35 Heat exchan er with cooled combustion chamber
36 Temperature sensor in CH flow
43 CH flow
44 Hot water flow
45 Gas
46 Cold water inlet
47 CH return
52 Solenoid valve 1
52.1 Solenoid valve 2
55 Filter
56 Gas valve CE 427
57 Main valve disc
61 Reset button
63 Adjustable as flow restrictor
64 Adjustin screw for min. as flow volume
69 Control valve
84 Motor
88 3-way valve
9 Venturi
91 Pressure relief valve
93 Water flow re ulator
94 Diaphra m
95 Pushrod with switch cam
96 Microswitch
97 Valve for hot water flow volume
98 Water valve
221 Flue duct
226 Fan
229 Air box
234 Testin point for flue as
234.1 Testin point for combustion air
317 Display
355 Plate-type heat exchan er
358 Condensate trap
4 Textdisplay
423 Siphon
443 Diaphra m
ϑ
33
29 30
226
229 234
234.1
26
6
36
29.1
63
15
45 47
20
43 44 46
13
8.1
84
90
97 98
93
94
95
96
91
69
64
57
52.1
56
52
55 7
355
M
358
18
88
max
max
1
2
34
5
E
ECO
0
317
61
4400
32
9
35
221
ϑ
27
6.1
6 720 610 597- 03.2O
423

6 720 610 602 GB (03.02)
8
Details of the appliance
1.8 Electrical wiring diagram
Fig. 4
4.1 I nition transformer
6Temperature limiter, heat exchan er
6.1 Hot water NTC sensor
9Flue as temperature limiter
18 Pump
32 Flame sensin electrode
33 I nition electrode
36 Temperature sensor in CH flow
52 Solenoid valve 1
52.1 Solenoid valve 2
56 Gas valve CE 427
61 Reset button
84 Motor, 3-way valve
96 Microswitch, hydraulic switch
135 Master switch
136 Temperature control for CH flow
151 Fuse, slow 2.5 A, AC 230 V
153 Transformer
161 Link
226 Fan
3 Code plu
3 2 Earth connection
31 Temperature control for hot water
312 Fuse, slow T 1,6 A
313 Fuse, slow T 0,5 A
317 Di ital display
328 Terminal block for AC 230 V Mains supply
328.1 Link
363 Indicator lamp for burner
364 Indicator lamp for power supply
365 “Chimney sweep” button
366 Service button
367 ECO button
4 Textdisplay
422 Connectin TR2
6
9
32
33
36
52.1
52
56
61
230 V
135
25 V
230V/AC
153 136
151 124789
161
M226
300
LNLsNs
328
LR
302
310
312
313
317 363
364 365 366
ECO
367
4.1
328.1
6.1
18
84
96
M
400
4
3F
M
6 720 610 602 - 02.1O
mains supply
422
o - orange g - green bl - black r - red p - purple
r
r
bl
bl
bl
bl bl
o
o
o
o
g
g
p
p
p

6 720 610 602 GB (03.02)
Details of the appliance
9
1.9 Technical data
Units
ZWBR 8-3
Natural gas
ZWBR 11-3
Propane
ZWBR 11-37
Natural gas
ZWBR 14-37
Propane
Max. rated heat output net 40/30˚C central heatin
Max. rated heat output net 50/30˚C central heatin
Max. rated heat output net 80/60˚C central heatin
kW
kW
kW
32.3
31.9
30.2
32.3
31.9
30.2
39.7
39.2
37.1
39.7
39.2
37.1
Max. rated heat input net kW 30.5 30.5 37.5 37.5
Min. rated heat output net 40/30˚C
Min. rated heat output net 50/30˚C
Min. rated heat output net 80/60˚C
kW
kW
kW
9.5
9.4
8.2
12.7
12.6
11.0
12.9
12.8
11.4
16.2
16.1
14.3
Min. rated heat input net kW 8.8 11.8 11.8 14.8
Max. rated heat output net, domestic hot water kW 30.2 30.2 37.1 37.1
Max. rated heat input net, domestic hot water kW 30.5 30.5 37.5 37.5
Maximum gas flow rate – After 1 minutes from lighting
Natural as G20 (CVnet 34.02 MJ/m3)m3/h 3.2 3.9
LPG (CVnet 88 MJ/m3)k /h 2.2 2.7
Gas supply pressure
Natural as G20 (CVnet 34.02 MJ/m3)mbar 20 - 20 -
LPG (CVnet 88 MJ/m3)mbar - 37 - 37
Expansion vessel
Char e pressure bar 0.75 0.75 0.75 0.75
Total capacity l 10 10 10 10
Hot water specifications
Hot water flow rate (factory settin ) l/min 8 8 8 8
Max. hot water flow rate l/min 14.0 14.0 14.0 14.0
Outlet temperature ran e ˚C 40 - 60 40 - 60 40 - 60 40 - 60
Max. permissible water supply pressure bar 10 10 10 10
Min. inlet pressure bar 0.2 0.2 0.2 0.2
Specific flow rate l/min 13.7 13.7 16.9 16.9
Flue
Flue as temp. 80/60˚C, rated/min. load ˚C 78/57 78/57 87/58 87/58
Flue as temp. 40/30˚C, rated/min. load ˚C 58/35 58/35 65/43 65/43
Residual delivery pressure
(inc. pressure drop in air intake duct) Pa 90 90 100 100
CO2 level at max. rated heat output
CO2 level at min. rated heat output
%
%9.4 9.2 11.0 11.0 9.2 9.2 11.0 11.0
NOx-class 5 5 5 5
SEDBUK fi ure, Band A % 90.3 90.3 90.3 90.3
Condensate
Max. condensation rate (tR = 30˚C) l/h 2.6 2.6 3.2 3.2
pH-value, approx. 4.8 4.8 4.8 4.8
General Data
Electrical power supply volta e AC ... V 230 230 230 230
Frequency Hz 50 50 50 50
Max. power consumption W 156 156 161 161
Noise output level dB(A) 39 39 41 41
Appliance protection ratin IP X4D X4D X4D X4D
Max. CH flow temperature ˚C nom. 90 nom. 90 nom. 90 nom. 90
Max. permissible operatin pressure (CH) bar 2.5 2.5 2.5 2.5
Permissible ambient temperatures ˚C 0 - 50 0 - 50 0 - 50 0 - 50
Nominal capacity of appliance l 3.75 3.75 3.75 3.75
Wei ht k 53 53 53 53
Table 2

6 720 610 602 GB (03.02)
10
Installation regulations
Condensate analysis, mg/l
Flue system
Elbow - 90 ° Equivalent len th 2 m
Bend - 45 ° Equivalent len th 1m
Gas supply
Domestic water performance
2 Installation regulations
Gas Safety (Installation & Use) Re ulations 1998: All
as appliances must be installed by a competent per-
son. Failure to install correctly could lead to prosecu-
tion.
The manufacturers notes must not be taken, in any way,
as overridin statutory obli ations.
The appliance must be installed in accordance with the
current IEE Wirin Re ulations, local Buildin Re ula-
tions, Buildin Standards (Scotland) (Consolidation),
bye-laws of the local Water Company, Health and
Safety Document 635 (Electricity at Work Re ulations
1989) and any other local requirements.
Product Liability re ulations indicate that, in certain cir-
cumstances, the installer can be held responsible, not
only for mistakes on his part but also for dama e result-
in from the use of faulty materials. We advise the
installer to avoid any risk by usin only quality approved
branded fittin s.
The relevant British Standards should be followed i.e.
•BS 6798: Specification for the installation of as
fired hot water boilers of rated input not exceedin
60kW
•BS 5449: Central Heatin for Domestic Premises
•BS 5546: Installation of as hot water supplies for
domestic purposes
•BS 5440:1: Flues and ventilation for as appliances
of rated input not exceedin 70 kW (net): Flues
•BS 5440:2: Flues and ventilation for as appliances
of rated input not exceedin 70 kW (net): Air
Supply
•BS 6891: Installation of low pressure as pipework
installations up to 28mm (R1).
•BS 7074:1: Code of practice for domestic heatin
and hot water supply
•BS 7671: Requirements for Electrical Installation.
These instructions must be followed.
Ammonium 1.2 Nickel 0.15
Lead ≤ 0.01 Mercury ≤ 0.0001
Cadmium ≤ 0.001 Sulphate 1
Chromium ≤ 0.005 Zinc ≤ 0.015
Halo enated
hydrocarbons ≤ 0.002
Tin ≤ 0.01
Hydrocarbons 0.015 Vanadium ≤ 0.001
Copper 0.028 pH-value 4.8
Table 3
HORIZONTAL 1 mm – Standard
Overall Diameter of Duct mm 100
Max. 4 m
Flue Terminal / Duct
Assembly Len th
mm 600
Extension Duct Len th mm 1000
Table 4
ALTERNATIVE HORIZONTAL 125 mm FLUE SYSTEM
Overall Diameter of Duct mm 125 Max. 13 m
(ZWBR 8-30)
Max. 10 m
(ZWBR 11-37)
includin turret
Flue Terminal / Duct
Assembly mm 1030
Table 5
VERTICAL 125 mm FLUE SYSTEM
Overall Diameter of Duct mm 125 Max. 15 m
(ZWBR 8-30)
Max. 12 m
(ZWBR 11-37)
Flue Terminal / Duct
Assembly mm 1360
Table 6
Total length of gas supply pipe
(metres)
Pipe diameter
(mm)
369
Gas dischar e rate (m3/h)
8.7 5.8 4.6 22
18.0 12.0 9.4 28
Table 7
ZWBR
8-30 ZWBR 11-37
Domestic
Water Flow
Rate l/min
Tempera-
ture Rise
30 °C 14.6 18.0
Tempera-
ture Rise
35 °C 12.5 15.4
Tempera-
ture Rise
40 °C 11.0 13.5
Maximum Mains pressure bar 10.0 10.0
Minimum Mains pressure bar 0.2 0.2
Table 8

6 720 610 602 GB (03.02)
Installation
11
3 Installation
3.1 Important remarks
BAppliance should only be installed in sealed central
heatin and hot water systems.
BTo avoid as formation in the system, alvanised
radiators or pipes must not be used.
BIf a room thermostat is used: do not fit a thermostatic
radiator valve on the radiator in the primary room.
BThis appliance uses an automatically variable pump.
An auto-bypass must not be fitted.
BAdd a suitable anti-freeze fluid to the water in the
central heatin system.
Suitable products are available from Betz-Dearborn
Tel.: [phone] and Fernox Tel.: 01799
550811.
BIn our experience, the addition of sealin a ents to
the water in the central heatin system can cause
problems (deposits in the heat exchan er). For that
reason we advise a ainst their use.
3.2 Domestic hot water
Any re ulations specified by the local water company
must be observed.
The final 600 mm of the mains cold water connection to
the applaince should be made in copper tube only.
The appliance is suitable for a mains supply havin a
maximum pressure of 10 bar. A pressure reducin valve
must be fitted, if necessary.
The hot water outlet temperature is set to be capable of
achievin a maximum of 60˚C. The maximum tempera-
ture and the frequency of the rechar e of the heat store
may be reset.
The water flow rate of 11.0 l/min (ZWBR 8-30) and
13.5 l/min (ZWBR 11-37) will ive a temperature rise
of 40˚C. If a hi her rise is required then the flow must
be reduced at the tap and the dischar e temperature
will rise up to the maximum set fi ure.
The temperature rise, upto the maximum set by the user,
is automatically maintained by the modulation of the
heat input. In winter, when the mains temperature is
very low, the water flow, adjusted at the tap or shower,
should be reduced to maintain the required delivery
temperature.
It is su ested that lon pipe runs to taps or showers
be insulated to prevent the rapid coolin of the water.
All types of sin le lever mixer taps and thermostatic
mixer units suitable for a mains pressure of up to 10 bar
can be used.
The head of a loose-head shower must not be allowed
to fall within 25 mm of the top the bath to prevent the
risk of water bein drawn back into the mains. Alterna-
tively the shower must be fitted with an anti-syphona e
device at the point of the flexible hose connections.
Over-rim bidets may be connected to the appliance
provided that it is in accordance with the requirements
of the local water company. The outlet(s) should be
shrouded and unable to have any temporary hand held
spray attached. No anti-syphona e arran ements are
necessary.
In exceptionally hard water areas a device to prevent
scale formation may be fitted or, alternatively, the maxi-
mum temperature reset to about 45˚C which may
reduce the risk of scale formation. The installation of a
scale inhibitor assembly should be in accordance with
the requirements of the local water company. Artificially
softened water must not be used to fill the central heat-
in system. An isolatin valve should be fitted to allow
for servicin .
Devices, such as water meters or back-flow pre-
vention valves, capable of preventing the flow of
expansion water must not be fitted unless sepa-
rate arrangements have been made.
A Zilmet Z160 expansion vessel is the preferred type. A
thread sealant compatible with potable water must be
used. The vessel should be connected into the cold
water mains inlet pipe as close as possible to the appli-
ance.
3.3 Sealed systems
The appliance must not be operated without the system
bein full of water, properly vented and pressurised.
The expansion vessel has a volume of 10 litres and is
char ed to a pressure of 0.75 bar.
The water capacity of the system is shown in table 11,
pa e 31. If a reater capacity is required then an addi-
tional expansion vessel must be fitted into the system
return as close to the appliance as possible. The system
pressure can be set up to a maximum of 1.5 bar with
1 bar bein the normal settin .
If the system pressure is reater than 2.5 bar when the
appliance is operatin at maximum temperature then an
additional expansion vessel must be fitted into the sys-
tem return as close to the appliance as possible.
The fillin point must be at low level and arran ed as
shown in fi s. 5 and 6.
The pressure relief valve is set to operate at 3 bar.
There must be no connection to the mains without the
approval of the local water company. All connections in
the system must be capable of withstandin a pressure
BAlways t rn off the gas cock before car-
rying o t any work on components
which carry gas.
iFixing of the appliance, gas and fl e con-
nections, commissioning of the system
and electrical connections may only be
carried o t by competent persons a thor-
ised by CORGI.

6 720 610 602 GB (03.02)
12
Installation
of up to 3 bar and the radiator valves conform to the
requirements of BS2767:10.
If Thermostatic Radiator Valves are fitted then it is rec-
ommended that the primary radiator is left open.
Repeated ventin probably indicates a leak and this
must be rectified to ensure the proper operation of the
appliance.
No galvanised radiators or pipes must be used.
If any system water treatment is required then
only products suitable for use with Aluminium
shall be used i.e Fernox- Copal or Superconcen-
trate or Sentinal X1 , in accordance with the
manufacturers instructions. The use of any other
substances will invalidate the guarantee. The pH
value of the system water must be less than 8 or
the appliance guarantee will be invalidated.
A drain cock to BS2879 must be fitted to the lowest
point of the system.
IMPORTANT: Check that no dirt is left in the
water pipework as this could damage the appli-
ance. Thoroughly flush the heating system and
the mains water supply before fitting the appli-
ance to the wall in accordance with the recom-
mendations of BS7593:1992.
Fig. 5 Sealed primary water system
Fig. 6
3.4 Siting the appliance
Regulations concerning the Installation Site
BRelevant national re ulations must be complied with
section 3.9.1.
BConsult the installation instructions for details of min-
imum clearances required.
Combustion air
In order to prevent corrosion, the combustion air must
not contain any corrosive substances.
Substances classed as corrosion-promotin include
halo enated hydrocarbons which contain chlorine and
fluorine compounds and are contained in some sol-
vents, paints, adhesives, aerosol propellants and
household cleaners, for example.
Surface temperature
The max. surface temperature of the casin and the flue
is less than 85 °C.
This means that, no special safety precautions are
required with re ard to flammable buildin materials
and fitted furniture. The specified clearences must be
maintained.
Domestic
hot water Central heating flow Radiator
valve
Lockshield
valve
Central heating return
A drain cock should be fitted at
the lowest point of the heating
circuit and the appliance
Water
main
BS stop valve.
Fixed spindle type
APPLIANCE
Refer to Fig.1
Appliance
water flow
diagram
WRAS approved
filling loop
6 720 610 576 -09.3O
Heating return
Non return
valve Non return valve Hose union
Test cock Temporary hose
Stop cock
Auto
air vent
Heating return
Stop
cock
Fill point
Non return
valve
Make up
vessel
1000mm (39 in)
above the highest
point of the system.
Sealed system filling and make up
6 720 611 137 - 29.1O

6 720 610 602 GB (03.02)
Installation
13
Cupboard/Compartment
The appliance can be installed in a cupboard/compart-
ment need for airin clothes providin that the require-
ments of BS6798 and BS5440:2 are followed. The low
casin losses from the appliance eliminate the need for
ventilation openin s in the compartment.
3.5 Wall mounting frame assembly
BTake the wall mountin frame out of the packa e and
screw to ether with 6 screws as shown in fi . 7. Use
the outer lu s on the top and bottom horizontal sec-
tions for the appliances that are 512 mm wide.
Fig. 7
BHold the wall-mountin frame a ainst the wall ensur-
in that it is vertical.
BMark the position of the flue duct hole if a rear flue is
to be used. Refer to fi . 1 and 16.
BMark the holes for the wall mountin frame onto the
wall, drill and plu the holes and screw the wall
mountin frame to the wall with the screws provided.
Fig. 8
BScrew the pre-plumbin manifold with two screws to
the wall mountin frame.
Fig. 9
3.6 Pre-piping the system
Fig. 10 Mani old
43 CH flow
47 CH return
112 Gas cock
171 Domestic hot water
172 Cold water relief
BA drain tap should be fitted at the lowest point of the
central heatin system.
BWRAS approved fillin loop must be fitted.
6 720 610 597-06.1O
6 720 610 597-07.1O
6 720 610 597-08.1O
200
260
6 720 610 576-06.1O
35
120-130
50
4743 172112
171

6 720 610 602 GB (03.02)
14
Installation
Condensate Termination and Route
The condensate connection on the British Gas/Bosch
appliances is in 22 mm plastic. The pipe should be
extended and run away from the appliance with a con-
stant fall of 2.5 ° or 40 mm in every metre.
The condensate pipe can terminate into any of four
areas:
Fig. 11
Whilst all of the above methods are acceptable it is
always the best practice to terminate the condense
pipe via an internal waste system.This will eliminate the
need for any external condensate pipe runs which can
be susceptible to freezin in extreme weather.
Fig. 12 Position o the condensate drain
External condensate pipework
All British Gas/Bosch condensin boilers have within a
syphonic condensate trap. Rather than the condensate
constantly drippin into the dischar e pipe, the con-
densate is collected into a trap which releases it in
100 ml quantities.
This will help prevent freezin occurrin .
If there is no alternative and the condensate pipe has to
be externally run, the followin should be considered:
•The pipe run should take the shortest practical route.
•The pipework should be insulated with weather
resistant insulation.
•The pipe should terminate as close as possible to the
round or drain, whilst still allowin the condensate
to safely disperse. This would prevent wind blowin
up the pipe.
•The pipework should be installed with the minimum
of horizontal runs and with a downward slope of at
least 2.5 °.
3.7 Fitting the appliance
BRemove packin , takin care to observe the instruc-
tions on the packin .
BLie the boiler on its back.
Removing the outer case
BRemove retainin screw on left hand side (1).
BPress both catch levers backwards (2).
Boiler
Boiler
Sink
Ø 22 min.
Ø 22 min.
Ø 22 min.
Ø 22 min.
Siphon
Siphon
75 min. trap
Invert
No length
restriction
No length
restriction
No length
restriction
Internal soil
and vent stack
The gradient of the discharge pipe
should be 2.5°(40 mm/m) minimum
The gradient of the discharge pipe
should be 2.5°(40 mm/m) minimum
The gradient of the discharge pipe
should be 2.5°(40 mm/m) minimum
An internal waste system An external waste system
The rainwater system An external purpose made soakaway
The gradient of the discharge pipe should be
2.5°(40 mm/m) minimum
Use waterproof pipe work
insulation in very exposed
positions
External length of
pipe 2m min.
Open end of pipe
direct into gully,
below ground but
above water level.
Open end of pipe
direct into gully,
below ground but
above water level
Open end of pipe direct
into gully, below ground
but above water level
75 min. trap
450 min.
Siphon
75 min. trap
Boiler
6 720 610 596 -03.1O
Boiler
Sink
6 720 610 602 - 03.1O
Benchmark: For optim m performance
after installation, this boiler and its asso-
ciated central heating system m st be
fl shed in accordance with the g ide-
lines given in BS5793:1992 “Treatment
of water in domestic hot water central
heating systems”.
iThe o ter case is sec red against na -
thorised removal by a retaining bracket
(electrical safety) at the bottom left.
Always sec re the o ter case with this
bracket again after refitting.

6 720 610 602 GB (03.02)
Installation
15
BLift off the top fixin lu s and slide the case forwards
and remove (3).
Fig. 13
Fixing the appliance
BFit the washers onto the as and water connections.
BLift the boiler onto the wall-mountin frame. The lu s
pass throu h the rectan ular holes in the boiler back
panel.
BTake care not to disturb the washers on the connec-
tions.
Connecting the flue duct
BFit flue duct connector onto appliance flue spi ot.
BSecure with the two screws supplied.
Fig. 14
BFor remainin installation of flue assembly, refer to
the relevant installation instructions.
3.8 Checking the connections
Water connections
BCheck that the O-rin s or seals are in place before
ti htenin the connection.
BTurn on the service valves for central heatin flow
and return and fill the heatin system throu h a
WRAS approved fillin loop.
BCheck all seals and unions for leaks (testin pres-
sure max. 3.0 bar as indicated by pressure au e).
BTurn on cold water service cock and fill hot water
system (testin pressure max. 10 bar).
BCheck all connections for leaks.
Gas supply pipe
BCheck that the seal is in place before ti htenin the
connection.
BTurn off as cock to protect as valve a ainst dam-
a e from excessive pressure.
BCheck as supply pipe.
BRelease the pressure on the as supply pipe.
3.9 Flue Systems
The only flue systems that may be used are those sup-
plied with the boiler.
The flue system must be installed in accordance with
the requirements of BS5440:1.
Standard 1 mm flue system
The standard concentric flue system provides for a hor-
izontal len th of upto 4 m. Full instructions for fittin this
flue are in Subsection 3.9.2 “Installation of the flue”.
Alternative 125 mm diameter flue systems
Installation instructions for the alternative flue systems
are sent with the appropriate flue kit.
Systems are available to ive a maximum horizontal
len th of 13 m (ZWBR 8-30) and 10 m (ZWBR 11-37).
A vertical flue system upto a hei ht of 15 m (ZWBR 8-
30) and 12 m (ZWBR 11-37) is available.
45° and 90° flue bends can be used with a correspond-
in reduction in flue len th of 2 m for each 90° bend
and 1 m for each 45° bend used.
IMPORTANT: Any horizontal flue system fitted to a
condensin boiler must incline towards the appliance at
an an le of 3 % (30 mm per metre len th) to prevent
condensate drippin from the flue terminal. This
means that the clearance above the appliance
must be increased to match the duct length.
Refer to fig. 1 on page 5.
1.
2
6 720 610 597 -09.1O
.
2.
3.
6 720 610 332-09.2R
1
3
2
4
1 .
2 .

6 720 610 602 GB (03.02)
16
Installation
3.9.1 Siting the Flue Terminal
The flue must be installed in accordance with
BS 5440:1 and the Buildin Re ulations. Flue termi-
nals in carports and under balconies are to be avoided.
The terminal must be positioned so that it does not
cause an obstruction nor the combustion products a
nuisance. See fi . 15 and table 9.
The terminal will, at times, ive out a plume of water
vapour and consideration must be iven to this when
choosin a terminal position. Keep clear of security
li htin , activated by passive infra-red sensin heads.
If the terminal is less than 2 m above a surface to which
people have access then a uard must be fitted. The
uard must be evenly spaced about the terminal with a
space of 50 mm in each direction and fixed with plated
screws.
A uard Type K6 for the standard horizontal flue, can be
obtained from Tower Flue Components, Vale Rise, Ton-
brid e TN9 1TB.
Fig. 15
Minimum dimensions of flue terminal positions (all types) (see fig. 15)
Dimension Terminal Position (kW input expressed in net) Balanced fl ues room sealed: anned draught
A1) Directly below an openin , air brick, openin windows, etc. 300 mm
B 1) Above an openin , air brick, openin window, etc. 300 mm
C 1) Horizontally to an openin , air brick, openin window, etc. 300 mm
D Below utters, soil pipes or drain pipes 75 mm
E Below eaves 200 mm
F 2) Below balconies or car port roof (lowest point) 200 mm
G From a vertical drain pipe or soil pipe 150 mm
H From an internal or external corner 300 mm
I Above round roof or balcony level 300 mm
J From a surface facin the terminal 600 mm
K From a terminal facin the terminal 1200 mm
L From an openin in the car port (e. . door, window) into the dwellin 1200 mm
M Vertically from a terminal on the same wall 1500 mm
N Horizontally from a terminal on the same wall 300 mm
O From the wall on which the terminal is mounted Not applicable
P From a vertical structure on the roof Not applicable
Q Above intersection with roof Not applicable
Table 9
1) In addition, the terminal should not be nearer than 150 mm (fanned drau ht) to an openin in the buildin fabric formed for the purpose of accommo-
datin a built-in element such as a window frame.
2) Not recommended.

6 720 610 602 GB (03.02)
Installation
17
3.9.2 Installation of the flue
The standard 100 mm diameter horizontal flue system
is suitable for len ths upto 4 m.
Flues upto 650 mm do not require an extension duct
assembly.
Flues between 1600 mm and 4000 mm require exten-
sion duct assemblies.
NOTE: Flue len ths between 650 mm and 730 mm
cannot be accomodated. Refer to fi . 17, 18, 19.
Standard system comprise: Flue turret - Flue turret
clamp - Terminal assembly - Wall sealin - plates.
Extension kit comprises: Air duct - Flue duct - Duct
clamp. Refer to fi . 20.
Instructions for fittin other flue systems are packed
with the relevant flue kit.
Check that the position chosen for the appliance is sat-
isfactory. Refer to fi . 16.
Fig. 16 Marking the position o the side lue opening
Fig. 17 Standard Flue
Appliance
120
Drilling point for
flue duct opening
3 %
(30 mm/metre)
Centre
line of
flue
opening
and
appliance
Centre line of
flue/air duct
Top of the
wall
mounting
frame
H
H
Standard Horizontal Flue 158 mm
Optional Horizontal Flue 121 mm 6 720 610 602-07.2O
Flue
Turret
No
Clamp
Maximum 650 mm
Terminal
Assembly
Outer
Wall
6 720 610 602 - 08.1O

6 720 610 602 GB (03.02)
18
Installation
Fig. 18 Flue with One Extension
Fig. 19 Flue with Extensions
Fig. 20 Flue Components
Maximum 1600mm
Flue
Turret
No
Clamp
Terminal
Assembly
Outer
Wall
Extension
Duct
6 720 610 602 - 09.1O
Clamp
Flue
Turret
No
Clamp
Clamp
Extension
Duct
Clamp
Extension
Duct
Terminal
Assembly
Outer
Wall
6 720 610 602 - 10.1O
Extension Air Duct
Extension Flue Duct
Terminal Assembly
Duct Clamp
Wall Sealing Plates
6 720 610 602 - 11.1O
Flue
Turret

6 720 610 602 GB (03.02)
Installation
19
3.9.3 Flue duct preparation and assembly
Measure the flue len th L. Refer to fi . 21, 22.
Fig. 21 Flue length - rear
Fig. 22 Flue length - side
Mark off the len ths shown onto the ducts and cut to
len th. The cuts must be square and free from burrs.
Terminal assembly outer (air) duct - L- 70 mm, inner
(flue) duct - L- 50 mm.The measurement is made from
the rid e at the terminal indicatin the outer face of the
wall. Refer to fi . 23.
Extension air duct - L- 70mm, flue duct - L- 50 mm.
The measurement is from the formed end.
Fig. 23 Flue terminal position
Assemble flue system completely. Push the ducts fully
to ether and clamp in the positions. The slope of the
terminal outlet must face downwards.
The assembly will be made easier if a solvent free
rease is li htly applied i.e Vaseline, to the male end of
the ducts.
NOTE: An inner wall sealing plate is provided
which should be fitted to the ducts before assem-
bly.
Push the assembly throu h the wall and fix the turret to
the appliance with the clamp. Refer to fi . 24.
Fig. 24 Flue turret
Ensure that the turret is fully entered into the socket on
the boiler. From the outside fix the outer wall plate to the
terminal and, after ensurin the duct is properly i nclined
towards the boiler, fix the plate to the wall.
If the terminal is within 2 m of the round where there is
access then an approved terminal uard must be fitted.
The uard must ive a clearance of at least 50 mm
around the terminal an be fixed with corrosion resistant
screws.
NOTE: THE FLUE MUST BE INCLINED T O THE
BOILER
L
120
6 720 610 602 - 12.1O
NOTE: THE FLUE MUST BE INCLINED T O THE
BOILER
L
6 720 610 602 - 13.1O
Outer
Wall
Face Flue Terminal
Raised Ring
locating the
terminal relative
to the outside
wall face
6 720 610 576 - 20.1O
Air and
Flue Duct
Entry into
silicone
rubber seals
Flue Turret
Clamp
Flue Socket
on Boiler 6 720 610 602 - 14.1O

6 720 610 602 GB (03.02)
20
Electrical connections
4 Electrical connections
All control and safety systems are built into the appli-
ance.
BAllow mains cable to protrude at least 50 cm from
wall.
BTo make splash-water proof (IP): cut the cable rom-
met hole size to match diameter of cable, see fi . 27.
It must be possible to isolate the appliance. The appli-
ance must be earthed.
The appliance must be connected to the mains throu h
a 6 A double pole isolator with a contact separation
3 mm in all poles and supplyin the appliance and con-
trols only. The wirin must comply with the current
requirements of the IEE Wirin Re ulations and any
local re ulations which apply.
•Supply: 230 V ~ 50 Hz, 140 Watts
• Mains cable: PVC insulated 0.75 mm2
(24 x 0.20 mm) to BS6500-Table 6.
Temperature rated 100˚C.
•Protection IPX4D
•External fuse 3 A.
4.1 Connecting the appliance
To ain access to the mains connection remove the
drop down facia cover. The drop down cover is
removed by lowerin it to the horizontal position and
pushin firmly upwards at the rear of the supports to
release the cover. Lift cover from the appliance.
After installation (or in the event of an electrical fault) the
electrical system shall be checked for short circuits,
fuse failure, incorrect polarity of connections, earth con-
tinuity and resistance to earth.
BPull out cover panel at the bottom and remove. Refer
to fi . 25.
Fig. 25
BRemove screw and slide terminal cover forwards to
remove. Refer to fi . 26.
Fig. 26
BAlways disconnect the power s pply to
the appliance at the mains before carry-
ing o t any work on the electrical sys-
tems and components.
0
1
2
34
5
E
6 720 610 332-10.1R
0
1
2
34
5
E
6 720 610 336 -18.1R