Table Of Contents - Worcester benchmark ZWB 7-25 R 25 HE Design, Installation And Servicing Instructions

Contents
Contents
Safety precautions
Symbols
1 Details of the appliance
1.1 EC Declaration of Conformity
1.2 Standard package
1.3 Description of appliance
1.4 Accessories
1.5 Casing dimensions
1.6 Layout of appliance
1.7 Function
1.8 Electrical wiring diagram
1.9 Technical data
2 Installation regulations
3 Installation
3.1 Important remarks
3.2 Domestic hot water
3.3 Sealed systems
3.4 Siting the appliance
3.5 Wall mounting frame assembly
3.6 Pre-piping the system
3.7 Fitting the appliance
3.8 Checking the connections
3.9 Flue Systems
3.9.1 Siting the Flue Terminal
3.9.2 Installation of the flue
3.9.3 Flue duct preparation and assembly
4 Electrical connections
4.1 Connecting the appliance
4.2 Mains Voltage external controls connections 22
5 Commissioning
5.1 Commissioning
5.2 Switching the appliance on/off
5.3 Switching on the central heating
5.4 System controls
5.5 Setting the domestic hot water temperature and
flow rate
5.5.1 Domestic hot water temperature
5.5.2 Hot water flow rate
5.6 Summer mode (hot water only)
5.7 Frost protection
5.8 Pump anti-seize function
5.9 Fault Condition
6 Individual settings
2
6.1 Mechanical settings
6.1.1 Checking the size of the expansion vessel
6.1.2 Setting the central heating flow temperature 27
6.1.3 Changing the heating pump characteristic
3
6.2 Settings on the Bosch Heatronic
6.2.1 Operating the Bosch Heatronic
6.2.2 Setting the anti-cycle time
3
(Service Function 2.4)
6.2.3 Setting the maximum CH flow temperature
4
(Service Function 2.5)
4
6.2.4 Setting the switching difference
4
(Service Function 2.6)
4
6.2.5 Setting the heating output
5
(Service Function 5.0)
5
6.2.6 Constant hot water cycle time
6
(Service Function 6.8)
7
6.3 Setting the gas/air ratio
8
9
7 Converting the appliance to different gas
types
11
7.1 Setting the gas/air ratio
7.2 Testing combustion air/flue gas at set heat out-
put
12
7.2.1 Testing the O2 or CO2 level in the combustion
12
air
12
7.2.2 Testing CO and CO2
12
13
14
8 Maintenance
14
8.1 Pre-Service Check List
15
8.2 Description of servicing operations
16
8.3 Replacement of Parts
16
8.3.1 PCB control board and transformer
17
8.3.2 Fan Assembly
18
8.3.3 Pump
19
8.3.4 Diverter valve
8.3.5 Diverter valve motor
8.3.6 Sensors
21
8.3.7 Gas Valve
21
8.3.8 Domestic Hot Water Heat Exchanger
8.3.9 Electrode assembly
8.3.10Pressure gauge
8.3.11Expansion vessel
23
8.3.12Pressure Relief Valve
23
8.3.13Burner
24
8.3.14Flow switch
24
8.3.15Primary Heat Exchanger
24
25
9 Appendix
25
9.1 Fault Codes
25
9.2 Short parts list
25
9.3 Heating/hot water output settings (N.G)
25
9.4 Heating/hot water output settings (L.P.G)
25
9.5 Operational Flow diagrams
26
9.5.1 Domestic hot water function
9.5.2 Central heating function
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6 720 611 441 GB (03.11)