Viessmann VITODENS 200-W Type B2HA Technical Manual page 20

Vitodens 200-W
Note
If the residual head of the circulation pump available as an acces-
sory is insufficient to overcome the following system pressure drop
values, install an additional, external circulation pump on site. In this
1
case, either the heating circuit connection with integral low loss
header, a system separation or a heating water buffer cylinder must
be used.
Pressure drop on the heating water side
For sizing a circulation pump (accessories or on-site provision)
600
60
500 50
400
40
300 30
200 20
100 10
0 0
0
Flow rate in l/h
Note
When the heating circuit pump and circulation pump for cylinder
heating are operated in parallel mode (no DHW priority control), we
recommend the installation of a DHW cylinder in the secondary side
(downstream of the system separation or the heating water buffer
cylinder) of the heating system.
VIESMANN
20
(cont.)
1000 2000 3000 4000 5000 6000 7000
VITODENS 200-W