Specifications

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Index
Index
1 Warning 3
2 Appliance details 5
2.1 Features 5
2.2 Specifications (Technical data) 5
2.3 Unpacking the heater 6
2.4 General rules to follow for safe operation 7
2.5 Dimensions and Min. installation clearances 8
3 Installation requirements 9
3.1 Specialized tools 9
3.2 Introduction 9
3.3 Proper location for installing your heater 9
4 Installation using Outdoor Kit (BTOK) 10
4.1 Warnings 10
4.2 Installing outdoor vent cap on the appliance 10
4.3 Selecting heater location 12
4.4 Mounting instructions 13
5 Installation using the Recess
Box (7 736 500 043) 14
5.1 Heater placement and clearances 14
6 Installation instructions 17
6.1 Gas piping & connections 17
6.2 Water connections 20
6.3 Water quality 20
6.4 Domestic hot water recirculation 21
6.5 Space heating applications 22
6.6 Measuring gas pressure 24
7 Electrical connections 25
7.1 Electrical power supply 25
7.2 Position of the fuses in control unit 25
8 Operation instructions 26
8.1 Description of LCD display 26
8.2 For your safety read before operating
your water heater 27
8.3 Power 27
8.4 Temperature selection 27
8.5 Use of optional remote control accessory
(part no. TSTAT2) 28
8.6 Operation 28
8.7 Reset button 28
8.8 Fan speed 29
8.9 Program button 31
8.10 Locked condition 31
9 Maintenance and service 31
9.1 Annual maintenance 31
9.2 Winterizing for seasonal use 32
9.3 Mineral scale build-up 32
9.4 Adjusting CO2 33
9.5 Program values 35
9.6 Control board diagnostics 36
10 Troubleshooting 37
10.1 Introduction 37
10.2 Burner does not ignite when hot
water is turned ON 37
10.3 Water is too hot 37
10.4 Water is not hot enough 37
10.5 Low water flow/pressure 38
10.6 Hot water temperature fluctuates
or goes cold at tap 38
10.7 Noisy burner/heater during operation 38
11 Problem solving 39
11.1 Error code diagnostics 39
12 Electrical diagram 43
13 Sensor resistance charts 44
14 GWH 940 ESO Functional scheme 46
15 Interior components diagram
and parts list 47
15.1 Interior components 47
15.2 Components diagram 49
16 Protecting the environment 55
17 Limited Warranty 56