Heating Mode - Viessmann VITODENS 200-W Installation And Service Instructions Manual

Control unit

Heating mode

The control unit determines a set boiler water tempera-
ture subject to outside temperature or room tempera-
ture (if a room temperature-dependent remote control
is connected) and to the slope
curve.
The determined set boiler water temperature is trans-
ferred to the burner control unit. From the set and
actual boiler water temperatures, the burner control
unit calculates the modulation level and regulates the
burner accordingly.
DHW heating with gas condensing combi boiler
If the flow switch detects a hot water draw-off
( 3 l/min), the burner, circulation pump and 3-way
>
valve are switched on or changed over. The burner
modulates to reach the DHW outlet temperature and is
limited on the boiler side by the temperature limiter.
DHW heating with gas condensing system boiler
The burner, circulation pump and 3-way valve are
switched on or changed over if the cylinder tempera-
ture lies 2.5 K below the set cylinder temperature.
Boosting DHW heating
This function is activated by specifying a second set
DHW temperature via parameter 58 in the "DHW"
group and activating the fourth DHW phase for DHW
heating.
level of the heating
/
The electronic temperature limiter inside the burner
control unit limits the boiler water temperature.
In the delivered condition, the set boiler water temper-
ature is 20 K higher than the set DHW temperature
(adjustable via parameter "60" in the "DHW" group). If
the actual cylinder temperature exceeds the set cylin-
der temperature by 2.5 K, the burner is switched off
and circulation pump run-on begins.
Heating is boosted during the periods selected in this
time phase.
Function description
141