Viessmann VITOCAL 222-S Installation And Service Instructions Manual page 84

Parts lists, internal unit
Internal unit hydraulics
Pos. Part
0045 Only for type AWT/AWT-AC 221.A04 to A07:
Reducers (set)
0046 Liquid line 10 mm
7
0047 Hot gas line
7
0048 Connection set
84
(cont.)
15 mm