Worcester ZWBR 7-28 HE plus User guide

Installation and Servicing Instructions
GREENSTAR HE plus combi
Wall mounted condensing boiler for central heating and mains
fed domestic hot water
6 720 610 598-00.1
O
ZWBR 7-28 HE plus GC-Number: 47 311 56
ZWBR 11-35 HE plus
GC-Number: 47 311 57
6 720 610 597 GB (01.07) OSW

6 720 610 597 GB (01.07)
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 Layout of appliance 6
1.7 Function 7
1.8 Electrical wiring diagram 8
1.9 Technical data 9
2 Installation regulations 11
3 Installation 11
3.1 Important remarks 11
3.2 Domestic hot water 12
3.3 Sealed systems 12
3.4 Siting the appliance 13
3.5 Wall mounting frame assembly 14
3.6 Pre-piping the system 14
3.7 Fitting the appliance 15
3.8 Checking the connections 16
3.9 Flue Systems 16
3.9.1 Siting the Flue Terminal 17
3.9.2 Installation of the flue 18
3.9.3 Flue duct preparation and assembly 20
4 Electrical connections 21
4.1 Connecting the appliance 21
4.2 Connecting TR2 Room thermostat 22
4.3 Mains Voltage external controls connections 22
5 Commissioning 23
5.1 Commissioning 23
5.2 Switching the appliance on/off 24
5.3 Switching on the central heating 24
5.4 System controls 24
5.5 Setting the domestic
hot water temperature and flow rate 25
5.5.1 Domestic hot water temperature 25
5.5.2 Hot water flow rate 25
5.6 Summer mode (hot water only) 25
5.7 Frost protection 25
5.8 Pump anti-seize function 25
5.9 Fault Condition 26
6 Text Display 27
6.1 General Description 27
6.2 Programming 27
6.2.1 Deleting a setting 28
6.2.2 Resetting all parameters
to their original settings 28
6.3 Menu structure 28
6.4 Setting the time/day 29
6.4.1 Setting the time and day 29
6.4.2 Holidays 29
6.5 Heating 29
6.5.1 Heating programme 29
6.5.2 Setting the Economy temperature 30
6.6 Hot water 30
6.6.1 Hot water programme 30
6.6.2 Hot water immediately 30
6.7 i Info 30
6.8 Settings 31
6.8.1 Heating (TR 2) 31
6.8.2 Hot Water
(Storage Tank, ZSBR models only) 31
6.8.3 Service 31
6.9 Individual timer programmes 31
7 Individual settings 32
7.1 Mechanical settings 32
7.1.1 Checking the size of the expansion vessel 32
7.1.2 Setting the central heating flow temperature 32
7.2 Settings on the Bosch Heatronic 32
7.2.1 General description 32
7.2.2 Setting the anti-cycle time
(Service Function 2.4) 33
7.2.3 Setting the maximum CH flow temperature
(Service Function 2.5) 33
7.2.4 Setting the heating output
(Service Function 5.0) 33
7.2.5 Constant hot water cycle time
(Service Function 6.8) 33
7.2.6 Variable pump settings
(Service Function 7.0) 33
7.3 Setting the gas/air ratio 33
8 Converting the appliance
to different gas types 34
8.1 Setting the gas/air ratio 34
8.2 Testing combustion air/flue gas at
set heat output 35
8.2.1 Testing the O
2
or CO
2
level
in the combustion air 35
8.2.2 Testing CO and CO
2
36
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 Pump 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
9.3.10Pressure gauge 44
9.3.11Expansion vessel 44
9.3.12Pressure Relief Valve 44
9.3.13Burner 44
9.3.14Flow switch 45
9.3.15Primary Heat Exchanger 45
10 Appendix 46
10.1 Fault Codes 46
10.2 Short parts list 47
10.3 Heating/hot water output settings
ZWBR 7-28 N.G. 48
10.4 Heating/hot water output settings
ZWBR 11-28 L.P.G 48
10.5 Heating/hot water output settings
ZWBR 11-35 N.G. 49
10.6 Heating/hot water output settings
ZWBR 14-35 L.P.G 49
10.7 Operational Flow diagrams 50
10.7.1Domestic hot water function 50
10.7.2Central heating function 51

6 720 610 597 GB (01.07)
Safety precautions
3
Safety precautions
If you smell gas
y Turn off gas service cock at the meter.
y Open windows and doors.
y Do not operate any electrical switches.
y Extinguish any naked flames.
y Telephone your gas company.
If you smell fumes from the appliance
y Switch off appliance (see page 24).
y Open windows and doors.
Fitting and modifications
y Fitting of the appliance or any controls to the appli-
ance may only be carried out by a competent engi-
neer in accordance wth the Gas Safety (Installation
and Use) Regulations 1998.
y Flue systems must not be modified in any ways other
than as described in the fitting instructions.
y This appliance is for use on sealed primary systems
only.
Maintenance
y The user is recommended: to have the system
regularly serviced in order to ensure that it functions
reliably and safely.
y Use only original spare parts!
Combustible materials
y Do not store or use any combustible materials
(paper, thinners, paints etc.) in the vicinity of the
appliance.
Health and safety
y This appliance contains no asbestos products.
y There is no potential hazard due to the appliance
being electrically unsafe.
y There are no substances used in the construction
that are a potential hazard in relation to the COSHH
Regulations (Control of Substances Hazardous to
Health Regulations 1988).
Combustion air/Ambient atmosphere
y The combustion air/ambient atmosphere should be
kept free of chemically aggressive substances (e.g.
halogenated hydrocarbons which contain chlorine or
fluorine compounds). This will prevent corrosion.
Instructions to the customer
y Explain to the customer how the appliance works and
how to operate it.
y Advise the user that he/she must not make any modi-
fications to the appliance or carry out any repairs on it.
y These instructions are to be left with the user or at
the Gas meter.
y Important: These instructions apply in the UK only.
Symbols
Safety instructions in this document
are identified by a warning-triangle sym-
bol and are printed on a grey back-
ground.
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.

6 720 610 597 GB (01.07)
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 Effi-
ciency Directive, Electromagnetic Compatibility Direc-
tive and the Low Voltage Directive.
1.2 Standard package
• Gas condensing combination boiler for central
heating and domestic hot water
• Control panel cover
• Wall mounting frame
• Clamp for securing flue duct kit
• Fixings (screws etc.)
• Set of documentation for appliance
• Pre-plumbing manifold
• Condensate drain pipe
• Filling loop.
1.3 Description of appliance
• Wall-mounted appliance, siting not dependent on
room size
• Natural gas models are low-emission appliances
• Multifunction display
• Bosch Heatronic control system with integrated
textdisplay for servicefunctions and faults
• 3-channel - digital timer for one heating circuit
• variable pump
• Automatic ignition
• Modulating control
• Full safety systems incorporating Bosch Heatronic
with flame ionisation monitoring, solenoid valves and
temperature sensors
• Concentric flue/air duct with testing point for
CO
2
/CO
• Regulated speed fan
• Pre-mix burner
• Temperature control for central heating
• Temperature sensor in domestic hot water
• Safety temperature limiter in 24 V electrical circuit
• Relief 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 BL0507
Category
UK II
2H 3P
Appliance Type C
13
, C
33
Table 1

6 720 610 597 GB (01.07)
Details of the appliance
5
1.4 Accessories
• Standard horizontal flue kit at 100 mm outside
diameter for flues upto 4 m in length.
• Flue duct kits for horizontal (125 mm outside
diameter) for flue lengths upto 10 m (ZWBR 11-35)
or 13 m (ZWBR 7-28) and vertical flue systems for
flue lengths 12 m (ZWBR 11-35) or 15m (ZWBR 7-
28). Fitting instructions are sent with these kits.
• Heating programmer
• Security kit.
1.5 Casing dimensions
Fig. 1
13 Manifold 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
min.
100 min.
100
512
850
101
103
6 720 610 602 - 01.1O
200
30
13
395 250
360
861
906
35
X
120
Y
Z

6 720 610 597 GB (01.07)
6
Details of the appliance
1.6 Layout of appliance
Fig. 2
4 Heatronic control
6 Heat exchanger safety temperature limiter
6.1 Hot water NTC sensor
7 Testing point for gas supply pressure
8.1 Pressure gauge
9 Flue gas temperature limiter
15 Relief valve
18 Pump
20 Expansion vessel
27 Automatic air vent
29 Air gas Mixer unit
32.1 Electrode assembly
36 Temperature sensor in CH flow
43 CH flow
63 Adjustable gas flow restrictor
64 Adjusting screw for min. gas flow volume
88 3-way valve (combi)
98 DHW flow 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 for combustion products
234.1 Testing point for combustion air
271 Flue duct
349 Cover plate for twin flue duct connection
355 Plate-type domestic hot water heat exchanger
358 Condensate trap
396 Hose Condensate trap
400 Textdisplay
415 Cover plate for cleaning 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
6 720 610 597 - 02.1O

6 720 610 597 GB (01.07)
Details of the appliance
7
1.7 Function
Fig. 3
4Bosch Heatronic control
6Temperature limiter, heat exchanger
6.1 Hot water NTC sensor
7Testing point for gas supply pressure
8.1 Pressure gauge
9Flue gas temperature limiter
13 Manifold
15 Safety valve
18 Central heating pump
20 Expansion vessel
26 Charging valve
27 Automatic vent
29 Mixer unit
29.1 Bi-metallic thermostat for combustion air compensation
30 Burner
32 Flame sensing electrode
33 Igniter electrode
35 Heat exchanger 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 gas flow restrictor
64 Adjusting screw for min. gas flow volume
69 Control valve
84 Motor
88 3-way valve
90 Venturi
91 Pressure relief valve
93 Water flow regulator
94 Diaphragm
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 Testing point for flue gas
234.1 Testing point for combustion air
317 Display
355 Plate-type heat exchanger
358 Condensate trap
400 Textdisplay
423 Siphon
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
345
E
ECO
0
317
61
4400
32
9
35
221
ϑ
27
6.1
6 720 610 597- 03.1O
423

6 720 610 597 GB (01.07)
8
Details of the appliance
1.8 Electrical wiring diagram
Fig. 4
4.1 Ignition transformer
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 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
300 Code plug
302 Earth connection
310 Temperature control for hot water
312 Fuse, slow T 1,6 A
313 Fuse, slow T 0,5 A
317 Digital 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
400 Textdisplay
422 Connecting 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
oog
g
p
p
p

6 720 610 597 GB (01.07)
Details of the appliance
9
1.9 Technical data
Units
ZWBR 7-28
Natural gas
ZWBR 11-28
Propane
ZWBR 11-35
Natural gas
ZWBR 14-35
Propane
Max. rated heat output net 40/30 °C central heating
Max. rated heat output net 50/30 °C central heating
Max. rated heat output net 80/60 °C central heating
kW
kW
kW
30.1
29.8
28.2
30.1
29.8
28.2
37.5
37.1
35.1
37.5
37.1
35.1
Max. rated heat input net kW 28.5 28.5 35.5 35.5
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
12.9
12.8
11.4
16.2
16.1
14.3
Min. rated heat input net kW 7.6 10.8 11.8 14.8
Max. rated heat output net, domestic hot water kW 28.2 28.2 35.1 35.1
Max. rated heat input net, domestic hot water kW 28.5 28.5 35.5 35.5
Maximum gas flow rate – After 10 minutes from lighting
Natural gas G20 (HiB = 9,5 kWh/m3)m
3/h 3.0 3.7
LPG (Hi= 12,8 kWh/kg) kg/h 2.2 2.5
Gas supply pressure
Natural gas G20 mbar 20 - 20 -
LPG mbar - 37 - 37
Expansion vessel
Charge pressure bar 0.75 0.75 0.75 0.75
Total capacity l 18 18 10 10
Hot water specifications
Hot water flow rate (factory setting) l/min 8 8 8 8
Max. hot water flow rate l/min 14 14 14 14
Outlet temperature range °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 16.0 16.0
Flue
Flue gas temp. 80/60 °C, rated/min. load °C 67/55 67/55 87/58 87/58
Flue gas temp. 40/30 °C, rated/min. load °C 43/32 43/32 65/43 65/43
Residual delivery pressure
(inc. pressure drop in air intake duct) Pa 80 80 100 100
CO2level at max. rated heat output
CO2level at min. rated heat output
%
%
9.5
9.2
11.3
11.0
9.2
9.2
11.0
11.0
NOx-class 5 5 5 5
SEDBUK figure, Band A % 90.6 90.6 90.3 90.3
Condensate
Max. condensation rate (tR= 30 °C) l/h 2.4 2.4 3.0 3.0
pH-value, approx. 4.8 4.8 4.8 4.8
General Data
Electrical power supply voltage AC ... V 230 230 230 230
Frequency Hz 50 50 50 50
Max. power consumption W 121 121 151 151
Noise output level dB(A) 37 37 40 340
Appliance protection rating IP X4D X4D X4D X4D
Max. CH flow temperature °C nom. 90 nom. 90 nom. 90 nom. 90
Max. permissible operating pressure (CH) bar 2.5 2.5 2.5 2.5
Permissible ambient temperatures °C 0 - 60 0 - 60 0 - 60 0 - 60
Nominal capacity of appliance l 3.75 3.75 3.75 3.75
Weight kg 53 53 53 53
Table 2

6 720 610 597 GB (01.07)
10
Details of the appliance
Condensate analysis, mg/l
Flue system
Elbow - 90 ° Bend - 45 °
Equivalent length 2 m Equivalent length 1m
Gas supply
Domestic water performance
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 of Duct mm 100
Max. 4 m
Flue Terminal / Duct
Assembly Length
mm 750
Extension Duct Length mm 1000
Table 4
ALTERNATIVE HORIZONTAL 125 mm FLUE SYSTEM
Overall Diameter of Duct mm 125
Max. 13 m
(ZWBR 7-28)
Max. 10 m
(ZWBR 11-35)
including turret
Flue Terminal / Duct
Assembly
mm 550
Extension Duct Length -
Fixed
mm 200
Extension Duct Length -
Fixed
mm 450
Extension Duct Length -
Fixed
mm 950
Extension Duct Length -
Fixed
mm 1950
Extension Duct Length -
Telescopic
mm 265-
375
Extension Duct Length -
Adjustable (Cut to length)
mm 200
Table 5
VERTICAL 125 mm FLUE SYSTEM
Overall Diametter of Duct mm 125
Max. 15 m
(ZWBR 7-28)
Max. 12 m
(ZWBR 11-35)
Flue Terminal / Duct
Assembly
mm 1360
Extension Duct Length mm 200
Extension Duct Length -
Fixed
mm 450
Extension Duct Length -
Fixed
mm 950
Extension Duct Length -
Fixed
mm 1950
Extension Duct Length -
Telescopic
mm 265-
375
Extension Duct Length -
Adjustable (Cut to length)
mm 450
Table 6
Total length of gas supply 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
ZWBR
7-28
ZWBR
11-35
Domestic
Water Flow
Rate l/min
Temperature
Rise
30 °C 13.7 17.0
Temperature
Rise
35 °C 11.7 14.6
Temperature
Rise
40 °C 10.3 12.8
Maximum Mains pressure bar 10.0 10.0
Minimum Mains pressure bar 0.2 0.2
Table 8