Viessmann Vitodens 333 Service Instructions Manual page 94

Function description
Weather–compensated control unit
The heating circulation pump is
switched ON and the three-way diver-
ter valve is changed over, if the cylin-
der primary temperature sensor
captures a temperature lower than the
set temperature.
At a boiler water temperature ≥ set
&
DHW temperature, the cylinder pri-
mary pump will be switched ON.
At a boiler water temperature ≤ set
&
DHW temperature, the burner will
be switched ON and, after the
required boiler water temperature
has been reached, the cylinder pri-
mary pump will be switched ON.
94
(cont.)
The DHW is regulated to the set tem-
perature via the cylinder primary tem-
perature sensor.
The cylinder continues to be heated
up after the draw-off process has
ended, until the set DHW temperature
has been reached at the cylinder pri-
mary temperature sensor.
The cylinder primary pump and the
three-way diverter valve remain ON
for a further 30 s.