*****INTERNAL*****30 R_D proof- 26.10.2022 / 09:15:46- VaillantGroup\DOC-agt\Brand\VIH_QW_190_6\ENG\OI-II_GB_0020291525
0020291525_04 Installation and maintenance instructions 45
Appendix
A Functional diagram
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1 Automatic air vent
2 Flow temperature sensor: Electric back-up heater
output
3 Building circuit, flow
4 Building circuit, return
5 Back-up heater
6 Heating flow from the outdoor unit
7 Heating return to the outdoor unit
8 Prioritising diverter valve
9 Protection anode
10 Cylinder temperature sensor
11 Manometer
12 Filling/draining cock
13 Isolation valve
14 Draining cock, heat pump and heating circuit
15 Domestic hot water cylinder's draining cock
16 Diaphragm expansion vessel
17 Cold water
18 Domestic hot water