Viessmann Vitodens 200-W Installation Instructions Manual page 30

Constant temperature control unit
DHW heating with gas fired combi boilers
If the flow switch detects that hot water is
being drawn (>3 l/min) then the burner, cir-
culation pump and 3-way valve are
switched on or changed over.
DHW heating with gas fired system boilers - utilising Viessmann DHW sensor
The burner, the circulation pump and the
3-way valve are started or changed over if
the cylinder temperature falls 2.5 K below
the set cylinder temperature.
30
(cont.)
The burner modulates according to the
DHW outlet temperature (max. 57ºC) and
is limited by the temperature limiter (82ºC)
on the primary side.
In the delivered condition, the set boiler
water temperatures is 20K higher than
the set DHW temperature (adjustable via
coding address "60"). The burner will be
switched OFF and the circulation pump
run-on time will begin, if the actual
cylinder temperature exceeds the set
cylinder by 2.5K.