Bosch ZSB18 - 2A Installation And Servicing Instructions page 14

14 | Pre-installation
S and Y plan systems:
NOTE: The boiler is fitted with its own
internal bypass.
1 Diverter valve
2 Radiator valve (flow)
3 Lock shield valve (return)
4 Bypass
Tab. 9
NOTE:
B A drain point should be fitted at the
lowest part of the heating circuit and
beneath the boiler.
Optional diverter valve
This boiler is designed to operate on a sealed system
only and will require a second return pipe from the water
cylinder to the wall mounting frame.
6 720 646 195a (2010/11)
S plan layout
4
Fig. 7 S plan
Y plan layout
with external diverter valve
1
M
Fig. 8 Y plan
System layout
with optional internal diverter valve
(not supplied with boiler)
Boiler flow
Cylinder return
Heating return
Fig. 9 System layout
AU/NZ
2
1
M
6720644743-05.1Wo
2
6720644743-06.1Wo
(
2
6720644743-07.1Wo
3
3
)
3