Bosch ZBR16-3A Installation And Service Instructions Manual page 17

Key to Fig. 7:
1 Ignition transformer
2 Boiler high limit dial
3 120 VAC connection
4 DHW tank primary pump or 3-way valve
5 External heating pump for unmixed heating circuit (secondary circuit)
6 Fuse T 6.3 A (120 VAC)
7 DHW thermostat
8 External safety high limit or low water cut off (LWCO)
9 BUS connection, e.g. heating control
10 Room thermostat – dry contact
11 Outdoor temperature sensor
12 Code plug
13 Diagnostic interface
14 ON/OFF switch
15 Transformer
16 Gas valve
17 Fan
18 Flue gas temperature limiter
19 Supply temperature sensor
20 Flame rod electrode
21 Ignition electrode
22 Boiler block temperature limiter
23 DHW tank temperature sensor (NTC)
24 Boiler circulator
25 Additional supply temperature limiter
26 External system supply temperature sensor
1) Set the service function 1.F,
2) Set the service function 5.E,
Copyright (optional information)
1)
page 67
page 71
Information about the appliance | 17
2)
or DHW recirculation pump
2)
6 720 643 068 (2011/06)