Viessmann Vitorond 100 VR1 Series Installation And Service Instructions Manual page 52

Connections
Installation Examples - Vitotronic
Legend
A Heating circuit
B Spring-loaded flow check valve
C Circulation pump
D Automatic air vent, (field supplied),
pressure relief valve, and temperature pressure gage
E Expansion tank
F Domestic hot water storage tank (indirect-fired)
G 4-Way mixing valve
H Low water cut-off (if required)
52
Vitorond 100, VR1-22 to -33 Installation and Service
(continued)
With one low-temperature circuit with 4-way mixing valve,
and with domestic hot water production
e.g. with Vitotronic 200, Model KW2 combined with
one mixing valve actuator accessory kit