Dhw Circulation - Viessmann Vitodens 200 Technical Manual

1.4 DHW circulation

DHW circulation pipes increase DHW
convenience and reduce the water
consumption.
These advantages result from the
immediate DHW availability to the
consumer.
However, poor insulation of the DHW
circulation pipe can lead to substantial
heat losses.
Vitodens 200 and 300
WW KW
KW
Wall mounted DHW cylinder
Vitodens 333
The volume flow of the on-site DHW circulation pump must not exceed 1.5 l/min.
WW KW
Z
DHW circulation without DHW circulation
pump connection set
DHW circulation for gas fired combi boilers
Due to the low water content of plate
heat exchangers the connection of
DHW circulation pipes cannot be
VITODENS
From a pipe length of 7 m upwards, we
recommend the installation of a DHW
circulation with appropriate thermal
insulation in accordance with the Energy
Savings Order [Germany].
In accordance with the Energy Savings
Act, the DHW circulation pipe should
include a circulation pump, a check valve
and a time switch for shutting down the
circulation during the night.
WW
KW
Z
DHW cylinder installed below the boiler
KW
WW
Z
DHW circulation with DHW circulation
pump connection set (integrated into the
boiler)
recommended in the case of gas fired
combi boilers.
Even the low heat losses of thermally
1.4 DHW circulation
Key to symbols
KW Cold water
WW DHW
Z DHW circulation
WW
Z
KW
DHW cylinder installed adjacent
to the boiler
Vitodens 343
WW
Z
KW
insulated DHW circulation pipes (to EnEV)
lead to a higher cycling frequency for gas
fired combi boilers (reheating).
200
300
1
KW
45