Viessmann Vitocal 252-A Series - Overview of Internal Components

141
Indoor unit with 2 integrated heating/cooling circuits
A
B
E
C
D
F
G
L
K
H
ONM
Fig. 93
A
Expansion vessel
B
Integrated buffer cylinder
C
Water pressure sensor
D
4/3-way valve
E
High limit safety cut-out (STB), instantaneous
heating water heater
F
Flow sensor
G
Heating/cooling circuit 1 heating circuit pump
H
Instantaneous heating water heater
K
Safety valve
L
Heating/cooling circuit 2 heating circuit pump
M
Heating/cooling circuit 2 flow temperature sensor
N
Heating/cooling circuit 1 flow temperature sensor
O
Return temperature sensor
Draining indoor unit on the secondary side
Danger
Heating water escaping uncontrolled may cause
scalding.
Allow the heating system to cool down before
draining.
1. Connect hoses to all drain valves. Open drain
valves.
2. Set the 4/3-way valve in turn to , and until
water no longer comes out.
Indoor unit maintenance
Overview of internal components (cont.)
6222080
Maintenance