Viessmann Vitotronic 200 KW2 Installation And Service Instructions Manual page 51

Heating circuit control
Flow temperature control
Differential temperature:
The differential temperature may be
adjusted via coding address 05.
As delivered condition: 8K.
The boiler water temperature should
be higher than the currently required
flow temperature of the mixer circuit
by a minimum value, called the
differential temperature.
H System with only one mixer circuit:
The set boiler water temperature
will be automatically held 8 K
above the set flow temperature.
H System with a heating circuit
without mixer and with a mixer
circuit:
The set boiler water temperature
operates in accordance with a
special heating curve. The
differential temperature of 8 K
towards the set flow temperature is
set up at the factory.
(cont.)
A Max. boiler water temperature
B Slope = 1.8 boiler circuit A1
C Slope = 1.2 mixer circuit M2
D Boiler water temperature
(with differential temperature = 8 K)
E Lower boiler water temperature
Function description
Outside temperature in °C
51