Benchmark ZWB 7-29 CC1 User manual

Installation and Servicing Instructions
CC1
Wall mounted condensing boiler for central heating and mains
fed domestic hot water
6 720 610 577-00.10
ZWB 7-29 CC1 GC-Number: 47 108 05
6 720 610 599 GB (03.02) OSW

6 720 610 599 GB (03.02)
2
Contents
Contents
Safet precautions 3
S mbols 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 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
5.10 Digital Timer 26
5.10.1Basic Settings 26
5.10.2B tton F nctions 26
5.10.3Programming 26
5.10.4Setting time and day 26
5.10.5Setting the timed periods 26
5.10.6Changing the Operating Mode 27
5.10.7Deleting Settings 27
5.10.8Completing Programming 27
5.10.9Time Display 27
6 Individual settings 28
6.1 Mechanical settings 28
6.1.1 Checking the size of the expansion vessel 28
6.1.2 Setting the central heating flow temperat re 28
6.1.3 Changing the heating p mp characteristic 28
6.2 Settings on the Bosch Heatronic 29
6.2.1 Operating the Bosch Heatronic 29
6.2.2 Selecting the p mp control mode for central
heating mode (Service F nction 2.2) 29
6.2.3 Setting the anti-cycle time
(Service F nction 2.4) 29
6.2.4 Setting the maxim CH flow temperat re
(Service F nction 2.5) 30
6.2.5 Setting the switching difference
(Service F nction 2.6) 30
6.2.6 Setting the heating o tp t
(Service F nction 5.0) 30
6.2.7 Constant hot water cycle time
(Service F nction 6.8) 30
6.3 Setting the gas/air ratio 30
7 Converting the appliance to
different gas t pes 31
7.1 Setting the gas/air ratio 31
7.2 Testing comb stion air/fl e gas at
set heat o tp t 33
7.2.1 Testing the O
2
or CO
2
level in
the comb stion air 33
7.2.2 Testing CO and CO
2
33
8 Maintenance 33
8.1 Pre-Service Check List 34
8.2 Description of servicing operations 35
8.3 Replacement of Parts 38
8.3.1 PCB control board and transformer 38
8.3.2 Fan Assembly 39
8.3.3 P mp 39
8.3.4 3-way diverter valve 40
8.3.5 3-way diverter valve motor 40
8.3.6 Sensors 40
8.3.7 Gas Valve 41
8.3.8 Domestic Hot Water Heat Exchanger 41
8.3.9 Electrode assembly 41
8.3.10Press re ga ge 41
8.3.11Expansion vessel 41
8.3.12Press re Relief Valve 41
8.3.13B rner 41
8.3.14Flow switch 42
8.3.15Primary Heat Exchanger 42
9 Appendix 43
9.1 Fa lt Codes 43
9.2 Short parts list 44
9.3 Heating/hot water o tp t settings (N.G) 45
9.4 Heating/hot water o tp t settings (L.P.G) 45
9.5 Operational Flow diagrams 46
9.5.1 Domestic hot water f nction 46
9.5.2 Central heating f nction 47

6 720 610 599 GB (03.02)
Safet precautions
3
Safet precautions
If ou smell gas
B Turn o gas service cock at the meter.
B Open windows and doors.
B Do not operate any electrical switches.
B Extinguish any naked lames.
B Telephone your gas company.
If ou smell fumes from the appliance
B Switch o appliance (see page 23).
B Open windows and doors.
Fitting and modifications
B Fitting o the appliance or any controls to the appli-
ance may only be carried out by a competent engi-
neer in accordance with the Gas Sa ety (Installation
and Use) Regulations 1998.
B Flue systems must not be modi ied in any ways other
than as described in the itting instructions.
B This appliance is or use on sealed primary systems
only.
Maintenance
B The user is recommended: to have the system
regularly serviced in order to ensure that it unctions
reliably and sa ely.
B Use only original spare parts!
Combustible materials
B Do not store or use any combustible materials
(paper, thinners, paints etc.) in the vicinity o the
appliance.
Health and safet
B This appliance contains no asbestos products.
B There is no potential hazard due to the appliance
being electrically unsa e.
B There are no substances used in the construction
that are a potential hazard in relation to the COSHH
Regulations (Control o Substances Hazardous to
Health Regulations 1988).
Combustion air/Ambient atmosphere
B The combustion air/ambient atmosphere should be
kept ree o chemically aggressive substances (e.g.
halogenated hydrocarbons which contain chlorine or
luorine 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 mod-
i ications to the appliance or carry out any repairs on
it.
B These instructions are to be le t with the user or at
the Gas meter.
B Important: These instructions apply in the UK only.
S mbols
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.

6 720 610 599 GB (03.02)
4
Details of the appliance
1 Details of the appliance
1.1 EC Declaration of Conformit
This appliance is in accordance with the applicable
requirements o the Gas Appliance Directive, Boiler
E iciency Directive, Electromagnetic Compatibility
Directive and the Low Voltage Directive.
1.2 Standard package
• Gas condensing combination boiler or central heat-
ing and domestic hot water
• Wall mounting rame
• Clamp or securing lue duct kit
• Fixings (screws etc.)
• Set o documentation or appliance
• Pre-plumbing mani old
• Condensate drain pipe.
1.3 Description of appliance
• Wall-mounted appliance, siting not dependent on
room size
• Natural gas models are low-emission appliances
• Multi unction display
• Bosch Heatronic control system
• Digital timer with 2 channels
• Automatic ignition
• Modulating control
• Full sa ety systems incorporating Bosch Heatronic
with lame ionisation monitoring, solenoid valves and
temperature sensors
• Concentric lue/air duct with testing point or
CO
2
/CO
• Regulated speed an
• Pre-mix burner
• Temperature control or central heating
• Temperature sensor in domestic hot water
• Sa ety temperature limiter in 24 V electrical circuit
• Three-speed central heating pump with automatic
vent
• Relie valve, pressure gauge, expansion vessel
• Flue gas temperature limiter (105 °C)
• Hot water priority circuit
• Motorised 3-way valve
• Plate-type heat exchange
• Condensate Trap.
PIN CE-0085 BL 0507
Category
UK II
2H 3P
Appliance Type C
13
, C
33
Table 1

6 720 610 599 GB (03.02)
Details of the appliance
5
1.4 Accessories
• Standard horizontal lue kit at 100 mm outside
diameter or lues upto 4 m in length.
• Flue duct kits or horizontal (125 mm outside
diameter) or lue lengths upto 13 m and vertical lue
systems or lue lengths upto 15 m. Fitting instruc-
tions are sent with these kits.
• Heating programmers
• Security kit.
1.5 Casing dimensions
Fig. 1
13 Mani old assembly
101 Outer case
103 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 servicing the appliance
min.
5
min.
5
850
440 395
200
360
861
906
200
30
6 720 610 601- 01.3O
101
103
35
X
13
Y
120
600
Z
**
*
*

6 720 610 599 GB (03.02)
6
Details of the appliance
1.6 La out of appliance
Fig. 2
4 Heatronic control
6 Heat exchanger sa ety temperature limiter
6.1 Hot water NTC sensor
7 Testing point or gas supply pressure
8.1 Pressure gauge
9 Flue gas temperature limiter
15 Relie valve
18 Pump
18.1 Pump speed selector switch
20 Expansion vessel
27 Automatic air vent
29 Air gas Mixer unit
32.1 Electrode assembly
36 Temperature sensor in CH low
43 CH low
63 Adjustable gas low restrictor
64 Adjusting screw or min. gas low volume
88 3-way valve (combi)
98 DHW low switch (combi)
102 Inspection window
120 Fixing points
221.1 Flue duct
221.2 Combustion air intake
226 Fan assembly
295 Appliance type sticker
234 Testing point or combustion products
234.1 Testing point or combustion air
271 Flue duct
349 Cover plate or twin lue duct connection
355 Plate-type domestic hot water heat exchanger
358 Condensate trap
415 Cover plate or cleaning access
416 Condensate collector
417 Clip or ixing outer case
418 Data plate
422 Digital timer
423 Siphon
6 720 610 599-01.2O
CH
C
8.1
29
102
226
234.1
271
416
221.1
221.2
20
43
9
63
358
64
7
355
6.1
417
15
4
18
415
6
36
32.1
234
349
120
418
295
422
88
88
18.1
423
27

6 720 610 599 GB (03.02)
Details of the appliance
7
1.7 Function
Fig. 3
4 Bosch Heatronic control
6 Temperature limiter, heat exchanger
6.1 Hot water NTC sensor
7Testing point or gas supply pressure
8.1 Pressure gauge
9Flue gas temperature limiter
13 Mani old
15 Sa ety valve
18 Central heating pump
20 Expansion vessel
26 Charging Valve
27 Automatic vent
29 Mixer unit
29.1 Bi-metallic thermostat or combustion air compensation
30 Burner
32 Flame sensing electrode
33 Igniter electrode
35 Heat exchanger with cooled combustion chamber
36 Temperature sensor in CH low
43 CH low
44 Hot water low
45 Gas inlet
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 gas low restrictor
64 Adjusting screw or min. gas inlet low volume
69 Control valve
84 Motor
88 3-way valve
90 Venturi
91 Pressure relie valve
93 Water low regulator
94 Diaphragm
95 Pushrod with switch cam
96 Microswitch
97 Valve or hot water low volume
98 Water valve
221 Flue duct
226 Fan
229 Inner casing
234 Testing point or lue gas
234.1 Testing point or combustion air
317 Display
355 Plate-type heat exchanger
358 Condensate trap
422 Digital timer
423 Siphon
443 Diaphragm
ϑ
33
29 30
32
226
229 234
234.1
9
35
221
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
ϑ
6.1 M
317
61
4
max
max
1
2
34
5
E
ECO
0
358
18
88
355
423
6 720 610 599-08.2O
CH
C
422
27
443

6 720 610 599 GB (03.02)
8
Details of the appliance
1.8 Electrical wiring diagram
Fig. 4
4.1 Ignition trans ormer
6Temperature limiter, heat exchanger
6.1 Hot water NTC sensor
9Flue gas temperature limiter
18 Pump
32 Flame sensing electrode
33 Ignition electrode
36 Temperature sensor in CH low
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 or CH low
151 Fuse, slow 2.5 A, AC 230 V
153 Trans ormer
161 Link
226 Fan
300 Code plug
302 Earth connection
310 Temperature control or hot water
312 Fuse, slow T 1,6 A
313 Fuse, slow T 0,5 A
314 Connector or programmer
315 Terminal block or programmer
317 Digital display
328 Terminal block or AC 230 V Mains supply
328.1 Link
363 Indicator lamp or burner
364 Indicator lamp or power supply
365 “Chimney sweep” button
366 Service button
367 ECO button
422 Digital timer
6
9
32
33
36
52.1
52
56
61
230 V
135
25 V
230V/AC
153 136
151 124789
315
161
M
226
300
LNLs
Ns
328
LR
302
310
312
313
314
317
318
363
364 365 366
ECO
367
4.1
328.1
M
6.1
18
96
84
M
6 720 610 599-07.2O
mains supply
422
r
r
bl
bl
bl
bl bl
o
oo
o
g
p
p
p
g
o - orange g - green bl - black r - red p - purple

6 720 610 599 GB (03.02)
Details of the appliance
9
1.9 Technical data
Units Natural gas Propane
Max. rated heat output net 40/30˚C centra heating
Max. rated heat output net 50/30˚C centra heating
Max. rated heat output net 80/60˚C centra heating
kW
kW
kW
31.2
30.9
29.2
31.2
30.9
29.2
Max. rated heat input net kW 29.5 29.5
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
8.4
8.3
7.4
11.6
11.4
10.5
Min. rated heat input net kW 7.6 10.8
Max. rated heat output net, domestic hot water kW 29.2 29.2
Max. rated heat input net, domestic hot water kW 29.5 29.5
Maximum gas flow rate – After 1 minutes from lighting
Natura gas G20 (CVnet 34.02 MJ/m
3
)m
3
/h 3.1 -
LPG (CVnet 88 MJ/m
3
) kg/h - 2.3
Gas supply pressure
Natura gas G20 (CVnet 34.02 MJ/m
3
) mbar 20 -
LPG (CVnet 88 MJ/m
3
) mbar - 37
Expansion vessel
Charge pressure bar 0.75 0.75
Tota capacity 10 10
Hot water specifications
Hot water f ow rate (factory setting) /min 8 8
Max. hot water f ow rate /min 14 14
Out et temperature range ˚C 40 - 60 40 - 60
Max. permissib e water supp y pressure bar 10 10
Min. in et pressure bar 0.2 0.2
Specific f ow rate /min 13.3 13.3
Flue
F ue gas temp. 80/60˚C, rated/min. oad ˚C 67/55 67/55
F ue gas temp. 40/30˚C, rated/min. oad ˚C 43/32 43/32
Residua de ivery pressure
(inc. pressure drop in air intake duct) Pa 80 80
CO
2
eve at max. rated heat output
CO
2
eve at min. rated heat output
%
%
9.2
8.8
10.8
10.5
NO
x
-c ass 5 5
SEDBUK figure, Band A % 90.6 90.6
Condensate
Max. condensation rate (t
R
= 30˚C) /h 2.5 2.5
pH-va ue, approx. 4.8 4.8
General Data
E ectrica power supp y vo tage AC ... V 230 230
Frequency Hz 50 50
Max. power consumption W 106 106
Noise output eve dB(A) 36 36
App iance protection rating IP X4D X4D
Max. CH f ow temperature ˚C nom. 90 nom. 90
Max. permissib e operating pressure (CH) bar 2.5 2.5
Permissib e ambient temperatures ˚C 0 - 50 0 - 50
Nomina capacity of app iance 3.75 3.75
Weight (exc uding packing) kg 46 46
Table 2

6 720 610 599 GB (03.02)
10
Installation regulations
Condensate anal sis, mg/l
Flue s stem
Elbow - 90 ° Equivalent length 2 m
Bend - 45 ° Equivalent length 1m
Gas suppl
Domestic water performance
2 Installation regulations
Gas Sa ety (Installation & Use) Regulations 1998: All
gas appliances must be installed by a competent per-
son. Failure to install correctly could lead to prosecu-
tion.
The manu acturers notes must not be taken, in any way,
as overriding statutory obligations.
The appliance must be installed in accordance with the
current IEE Wiring Regulations, local Building Regula-
tions, Building Standards (Scotland) (Consolidation),
bye-laws o the local Water Company, Health and
Sa ety Document 635 (Electricity at Work Regulations
1989) and any other local requirements.
Product Liability regulations indicate that, in certain cir-
cumstances, the installer can be held responsible, not
only or mistakes on his part but also or damage result-
ing rom the use o aulty materials. We advise the
installer to avoid any risk by using only quality approved
branded ittings.
The relevant British Standards should be ollowed i.e.
• BS 6798: Speci ication or the installation o gas
ired hot water boilers o rated input not exceeding
60kW
• BS 5449: Central Heating or Domestic Premises
• BS 5546: Installation o gas hot water supplies or
domestic purposes
• BS 5440:1: Flues and ventilation or gas appliances
o rated input not exceeding 70 kW (net): Flues
• BS 5440:2: Flues and ventilation or gas appliances
o rated input not exceeding 70 kW (net): Air
Supply
• BS 6891: Installation o low pressure gas pipework
installations up to 28mm (R1).
• BS 7074:1: Code o practice or domestic heating
and hot water supply
• BS 7671: Requirements or 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
Halogenated
hydrocarbons ≤ 0.002
Tin ≤ 0.01
Hydrocarbons 0.015 Vanadium ≤ 0.001
Copper 0.028 pH-value 4.8
Table 3
HORIZONTAL 100 mm – Standard
Overall Diameter o Duct mm 100
Max.
4 m
Flue Terminal / Duct
Assembly Length
mm 600
Extension Duct Length mm 1000
Table 4
ALTERNATIVE HORI ONTAL 125 mm FLUE
SYSTEM
Overall Diameter o Duct mm 125 Max.
13 m
(inclu-
ding
turret)
Flue Terminal / Duct Assembly mm 1030
Table 5
VERTICAL 125 mm FLUE SYSTEM
Overall Diameter o Duct mm 125 Max.
15 m
Flue Terminal / Duct Assembly mm 1360
Table 6
Total length of gas suppl pipe
(metres)
Pipe diameter
(mm)
369
Gas discharge rate (m3/h)
8.7 5.8 4.6 22
18.0 12.0 9.4 28
Table 7
Domestic
Water Flow
Rate l/min
Temperat re
Rise 30 °C
14.2
Temperat re
Rise 35 °C 12.1
Temperat re
Rise 40 °C 10.6
Maxim m Mains press re bar 10.0
Minim m Mains press re bar 0.2
Table 8

6 720 610 599 GB (03.02)
Installation
11
3 Installation
3.1 Important remarks
BAppliance should only be installed in sealed central
heating systems.
BTo avoid gas ormation in the system, galvanised
radiators or pipes must not be used.
BI a room thermostat is used: do not it a thermostatic
radiator valve on the radiator in the primary room.
BAdd a suitable anti- reeze luid compatible with alu-
minium to the water in the central heating system.
Suitable products are available rom Betz-Dearborn
Tel.: [phone] and Fernox Tel.: 01799
550811.
BIn our experience, the addition o sealing agents to
the water in the central heating system can cause
problems (deposits in the heat exchanger). For that
reason we advise against their use.
3.2 Domestic hot water
Any regulations speci ied by the local water company
must be observed.
The inal 600 mm o the mains cold water connection to
the applaince should be made in copper tube only.
The appliance is suitable or a mains supply having a
maximum pressure o 10 bar. A pressure reducing valve
must be itted, i necessary.
The hot water outlet temperature is set to be capable o
achieving a maximum o 60˚C. The maximum tempera-
ture and the requency o the recharge o the heat store
may be reset.
A water low rate o 10.6 l/min will give a temperature
rise o 40˚C. I a higher rise is required then the low
must be reduced at the tap and the discharge temper-
ature will rise up to the maximum set igure.
The temperature rise, upto the maximum set by the user,
is automatically maintained by the modulation o the
heat input. In winter, when the mains temperature is
very low, the water low, adjusted at the tap or shower,
should be reduced to maintain the required delivery
temperature.
It is suggested that long pipe runs to taps or showers
be insulated to prevent the rapid cooling o the water.
All types o single lever mixer taps and thermostatic
mixer units suitable or a mains pressure o up to 10 bar
can be used.
The head o a loose-head shower must not be allowed
to all within 25 mm o the top the bath to prevent the
risk o water being drawn back into the mains. Alterna-
tively the shower must be itted with an anti-syphonage
device at the point o the lexible hose connections.
Over-rim bidets may be connected to the appliance
provided that it is in accordance with the requirements
o the local water company. The outlet(s) should be
shrouded and unable to have any temporary hand held
spray attached. No anti-syphonage arrangements are
necessary.
In exceptionally hard water areas a device to prevent
scale ormation may be itted or, alternatively, the maxi-
mum temperature reset to about 45˚C which may
reduce the risk o scale ormation. The installation o a
scale inhibitor assembly should be in accordance with
the requirements o the local water company. Arti icially
so tened water must not be used to ill the central heat-
ing system. An isolating valve should be itted to allow
or servicing.
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 pre erred 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 s stems
The appliance must not be operated without the system
being ull o water, properly vented and pressurised.
The expansion vessel has a volume o 10 litres and is
charged to a pressure o 0.75 bar.
The water capacity o the system is shown in table 13,
page 28. I a greater capacity is required then an addi-
tional expansion vessel must be itted into the system
return as close to the appliance as possible. The system
pressure can be set up to a maximum o 1.5 bar with 1
bar being the normal setting.
I the system pressure is greater than 2.65 bar when the
appliance is operating at maximum temperature then an
additional expansion vessel must be itted into the sys-
tem return as close to the appliance as possible.
The illing point must be at low level and arranged as
shown in igs. 5 and 6.
The pressure relie valve is set to operate at 3 bar.
There must be no connection to the mains without the
approval o the local water company. All connections in
the system must be capable o withstanding a pressure
o up to 3 bar and the radiator valves con orm to the
requirements o BS 2767:10.
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.

6 720 610 599 GB (03.02)
12
Installation
I Thermostatic Radiator Valves are itted then it is rec-
ommended that the the primary radiator is le t open.
Repeated venting probably indicates a leak and this
must be recti ied to ensure the proper operation o the
appliance.
No galvanised radiators or pipes must be used.
If an s stem water treatment is required then
onl products suitable for use with Aluminium
shall be used i.e Fernox- Copal or Superconcen-
trate or Sentinal X100, in accordance with the
manufacturers instructions. The use of an other
substances will invalidate the guarantee. The pH
value of the s stem water must be less than 8 or
the appliance guarantee will be invalidated.
A drain cock to BS2879 must be itted to the lowest
point o the system.
IMPORTANT: Check that no dirt is left in the
water pipework as this could damage the appli-
ance. Thoroughl flush the heating s stem and
the mains water suppl 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 regulations must be complied with
section 3.9.1.
BConsult the installation instructions or details o min-
imum clearances required.
Combustion air
In order to prevent corrosion, the combustion air must
not contain any corrosive substances.
Substances classed as corrosion-promoting include
halogenated hydrocarbons which contain chlorine and
luorine compounds and are contained in some sol-
vents, paints, adhesives, aerosol propellants and
household cleaners, or example.
Surface temperature
The max. sur ace temperature o the casing and the lue
is less than 85 °C.
This means that, no special sa ety precautions are
required with regard to lammable building materials
and itted urniture. The speci ied clearences must be
maintained.
Cupboard/Compartment
The appliance can be installed in a cupboard/compart-
ment need or airing clothes providing that the require-
ments o BS6798 and BS5440:2 are ollowed. The low
casing losses rom the appliance eliminate the need or
ventilation openings in the compartment.
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

6 720 610 599 GB (03.02)
Installation
13
3.5 Wall mounting frame assembl
BTake the wall mounting rame out o the package and
screw together with 6 screws as shown in ig. 7. Use
the inner lugs on the top and bottom horizontal sec-
tions or the appliances that are 440 mm wide.
Fig. 7
BHold the wall-mounting rame against the wall ensur-
ing that it is vertical.
BMark the position o the lue duct hole i a rear lue is
to be used. Re er to ig. 1 and 16.
BMark the holes or the wall mounting rame onto the
wall, drill and plug the holes and screw the wall
mounting rame to the wall with the screws provided.
Fig. 8
BScrew the pre-plumbing mani old with two screws to
the wall mounting rame.
Fig. 9
3.6 Pre-piping the s stem
Fig. 10 Mani old
43 CH low
47 CH return
112 Gas cock
171 Domestic hot water
172 Cold water relie
BA drain tap should be itted at the lowest point o the
central heating system.
BWRAS approved illing loop must be itted.
6 720 610 576-04.1O
6 720 610 576-05.1O
6 720 610 576-11.1O
200
260
6 720 610 576-06.1O
35
120-130
50
4743 172112
171

6 720 610 599 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 rom the appliance with a con-
stant all o 2.5 ° or 40 mm in every metre.
The condensate pipe can terminate into any o our
areas:
Fig. 11
Whilst all o 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 or any external condensate pipe runs which can
be susceptible to reezing in extreme weather.
Fig. 12 Position o the condensate drain
External condensate pipework
All British Gas/Bosch condensing boilers have within a
syphonic condensate trap. Rather than the condensate
constantly dripping into the discharge pipe, the con-
densate is collected into a trap which releases it in
100 ml quantities.
This will help prevent reezing occurring.
I there is no alternative and the condensate pipe has to
be externally run, the ollowing 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
ground or drain, whilst still allowing the condensate
to sa ely disperse. This would prevent wind blowing
up the pipe.
• The pipework should be installed with the minimum
o horizontal runs and with a downward slope o at
least 2.5 °.
3.7 Fitting the appliance
BRemove packing, taking care to observe the instruc-
tions on the packing.
BLie the boiler on its back.
Removing the outer case
BTurn the clips with a screwdriver.
BSlide the outer case upwards and then orwards to
remove.
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 two clips (electrical
safety).
Always sec re the o ter case with those
clips again after refitting.

6 720 610 599 GB (03.02)
Installation
15
BRemove the plastic caps rom the boiler connec-
tions.
Fig. 13
Fixing the appliance
BFit the washers onto the gas and water connections.
BLi t the boiler onto the wall-mounting rame. The lugs
pass through the rectangular holes in the boiler back
panel.
BTake care not to disturb the washers on the connec-
tions.
Connecting the flue duct
BFit lue duct connector onto appliance lue spigot.
BSecure with the two screws supplied.
Fig. 14
BFor remaining installation o lue assembly, re er to
the relevant installation instructions.
3.8 Checking the connections
Water connections
BCheck that the O-rings or seals are in place be ore
tightening the connection.
BTurn on the service valves or central heating low
and return and ill the heating system through a
WRAS approved illing loop.
BCheck all seals and unions or leaks (testing pres-
sure max. 3.0 bar as indicated by pressure gauge).
BTurn on cold water service cock and ill hot water
system (testing pressure max. 10 bar).
BCheck all connections or leaks.
Gas suppl pipe
BCheck that the seal is in place be ore tightening the
connection.
BTurn o gas cock to protect gas valve against dam-
age rom excessive pressure.
BCheck gas supply pipe.
BRelease the pressure on the gas supply pipe.
3.9 Flue S stems
The only lue systems that may be used are those sup-
plied with the boiler.
The lue system must be installed in accordance with
the requirements o BS5440:1.
Standard 100 mm flue s stem
The standard concentric lue system provides or a hor-
izontal length o upto 4 m. Full instructions or itting this
lue are in Subsection 3.9.2 “Installation o the lue”.
Alternative 125 mm diameter flue s stems
Installation instructions or the alternative lue systems
are sent with the appropriate lue kit.
Systems are available to give a maximum horizontal
length o 13 m.
A vertical lue system upto a height o 15 metres is avail-
able.
45° and 90° lue bends can be used with a correspond-
ing reduction in lue length o 2m or each 90° bend and
1 m or each 45° bend used.
IMPORTANT: Any horizontal lue system itted to a
condensing boiler must incline towards the appliance at
an angle o 3 % (30 mm per metre length) to prevent
condensate dripping rom the lue 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.
6 720 610 599-02.1O
CH
C
6 720 610 332-09.2R
1
3
2
4
1 .
2 .

6 720 610 599 GB (03.02)
16
Installation
3.9.1 Siting the Flue Terminal
The lue must be installed in accordance with
BS 5440:1 and the Building Regulations. 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 ig. 15 and table 9.
The terminal will, at times, give out a plume o water
vapour and consideration must be given to this when
choosing a terminal position. Keep clear o security
lighting, activated by passive in ra-red sensing heads.
I the terminal is less than 2 m above a sur ace to which
people have access then a guard must be itted. The
guard must be evenly spaced about the terminal with a
space o 50 mm in each direction and ixed with plated
screws.
A guard Type K6 or the standard horizontal lue, can be
obtained rom Tower Flue Components, Vale Rise, Ton-
bridge TN9 1TB.
Fig. 15
Minimum dimensions of flue terminal positions (all t pes) (see fig. 15)
Dimension Terminal Position (kW input expressed in net) Balanced flues room sealed: Fanned draught
A1) Directly below an opening, air brick, opening windows, etc. 300 mm
B 1) Above an opening, air brick, opening window, etc. 300 mm
C 1) Horizontally to an opening, air brick, opening window, etc. 300 mm
D Below gutters, soil pipes or drain pipes 75 mm
E Below eaves 200 mm
F 2) Below balconies or car port roo (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 ground roo or balcony level 300 mm
J From a sur ace acing the terminal 600 mm
K From a terminal acing the terminal 1200 mm
L From an opening in the car port (e. g. door, window) into the dwelling 1200 mm
M Vertically rom a terminal on the same wall 1500mm
N Horizontally rom 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 roo Not applicable
Q Above intersection with roo Not applicable
Table 9
1) In addition, the terminal should not be nearer than 150 mm ( anned draught) to an opening in the building abric ormed or the purpose o accommo-
dating a built-in element such as a window rame.
2) Not recommended.

6 720 610 599 GB (03.02)
Installation
17
3.9.2 Installation of the flue
The standard 100 mm diameter horizontal lue system
is suitable or lengths 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 lengths between 650 mm and 730 mm
cannot be accomodated. Re er to Fig. 17, 18, 19.
Standard system comprise: Flue turret - Flue turret
clamp - Terminal assembly - Wall sealing - plates.
Extension kit comprises: Air duct - Flue duct - Duct
clamp. Re er to Fig. 20.
Instructions or itting other lue systems are packed
with the relevant lue kit.
Check that the position chosen or the appliance is sat-
is actory Re er to Fig. 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

6 720 610 599 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

6 720 610 599 GB (03.02)
Installation
19
3.9.3 Flue duct preparation and assembly
Measure the flue length L. Refer to fig. 21, 22.
Fig. 21 Flue length - rear
Fig. 22 Flue length - side
Mar off the lengths shown onto the ducts and cut to
length. 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 ridge at the terminal indicating the outer face of the
wall. Refer to fig. 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
together and clamp in the positions. The slope of the
terminal outlet must face downwards.
The assembly will be made easier if a solvent free
grease is lightly applied i.e Vaseline, to the male end of
the ducts.
NOTE: An inner wall sealing plate is provided
w ic s ould be fitted to t e ducts before assem-
bly.
Push the assembly through the wall and fix the turret to
the appliance with the clamp. Refer to fig. 24.
Fig. 24 Flue turret
Ensure that the turret is fully entered into the soc et on
the boiler. From the outside fix the outer wall plate to the
terminal and, after ensuring the duct is properly i nclined
towards the boiler, fix the plate to the wall.
If the terminal is within 2 m of the ground where there is
access then an approved terminal guard must be fitted.
The guard must give a clearance of at least 50 mm
around the terminal an be fixed with corrosion resistant
srews.
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

6 720 610 599 GB (03.02)
20
Electrical connections
4 Electrical connections
All control and sa ety systems are built into the appli-
ance.
BAllow mains cable to protrude at least 50 cm rom
wall.
BTo make splash-water proo (IP): cut the cable grom-
met hole size to match diameter o cable, see Fig. 27.
It must be possible to isolate the appliance. The appli-
ance must be earthed.
The appliance must be connected to the mains through
a 6 A double pole isolator with a contact separation
3 mm in all poles and supplying the appliance and con-
trols only. The wiring must comply with the current
requirements o the IEE Wiring Regulations and any
local regulations 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 use 3 A.
4.1 Connecting the appliance
To gain access to the mains connection remove the
drop down acia cover. The drop down cover is
removed by lowering it to the horizontal position and
pushing irmly upwards at the rear o the supports to
release the cover. Li t cover rom the appliance.
A ter installation (or in the event o an electrical ault) the
electrical system shall be checked or short circuits,
use ailure, incorrect polarity o connections, earth con-
tinuity and resistance to earth.
BPull out cover panel at the bottom and remove. Re er
to ig. 25.
Fig. 25
BRemove screw and slide terminal cover orwards to
remove. Re er to ig. 26.
Fig. 26
BCut cable grommet to diameter o cable.
Fig. 27
BFeed cable through cable grommet and connect the
mains supply cable, see ig. 28.
BSecure cable in cable grommet by means o cable
grip.
Fig. 28
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
6 720 610 599 -03.1
O
CH
C
0
1
2
34
5
E
6 720 610 332-12.1R
13-14
10-12
8-9
5-7
LNNLL
R
SS
4130-14.1R