Viessmann VITOCAL 151-A Installation And Service Instructions Manual page 37

Connecting the secondary circuit
This also particularly applies when connecting solar
thermal systems.
Connecting the secondary side
Note
So that the system can be filled and flushed via the
commissioning assistant, fit a three-way ball valve
into each of the following lines:
Flow and return lines for heating/cooling circuit 1/
■
heating water buffer cylinder
■ Flow and return lines to the outdoor unit
If required, install 1 shut-off valve in each flow and
return DHW cylinder.
Installing the hydraulic connection set (accesso-
ries)
"Hydraulic connection set" installation instruc-
tions
Note
The following diagram shows an example of the
hydraulic connection set for surface mounting with
upward connection.
(cont.)
Indoor unit with 1 integrated heating/cooling cir-
cuit
Fig. 28
Heating water return, heating/cooling circuit 1:
A
G 1 (female thread)
¼
DHW: G
B
Outdoor unit return (heating water outlet): G 1
C
(female thread)
Outdoor unit flow (heating water inlet): G 1
D
(female thread)
Cold water: G
E
Heating water flow, heating/cooling circuit 1: G 1
F
(female thread)
Making the hydraulic connections
1. If the expansion vessel fitted is insufficient, equip
the secondary circuit on site with an additional
expansion vessel.
Installation sequence
F
E
D
C
B
A
(female thread)
¾
(female thread)
¾
¼
¼
¼
37