Viessmann Vitosol
100 Technical Manual page 48

3.2 Sizing pipe diameters and circulation pump
Connection from the r.h. side
For larger systems
48
Connection from the l.h. side (preferred version)
C C
A
15x1
B
C
A
22x1
B
18x1
B
15x1
A
A Flow
B Return
C Air vent valve
VITOSOL