Viessmann Vitotronic 200 KW2 Installation And Service Instructions Manual page 55

Cylinder temperature control
Control sequence
Pump run−on
H The cylinder primary pump runs on
after cylinder heating, until
the difference between the boiler
water and the DHW temperature
is less than 7 K
or
the weather−compensated set
boiler water temperature has
been reached or
or
the set DHW temperature has
been exceeded by 5 K
or
the maximum run−on time
(adjustable via coding
address 62) has been reached.
H Without the cylinder primary pump
running on for cylinder heating
(code 62:0).
Code 55:0
Cylinder heating
DHW cylinder goes cold
(set value 2.5 K, adjustable via
coding address 59)
The set boiler water temperature is
adjusted 20 K higher than the set
DHW temperature (adjustable via
coding address 60).
H Starting the cylinder primary pump
subject to boiler temperature (code
61:0):
The cylinder primary pump starts
when the boiler water temperature
is 7 K higher than the DHW
temperature.
H Immediate start of the cylinder
primary pump (code 61:1).
(cont.)
The DHW cylinder is hot
(set value +2.5 K)
The set boiler water temperature is
returned to the weather−
compensated value.
Code 55:1
Adaptive cylinder heating
With adaptive cylinder heating, the
speed of the temperature rise during
DHW heating is taken into account.
Also taken into account is the
question of whether the boiler will
be required to supply heat after the
cylinder has been heated up or
whether residual boiler heat should
be transferred to the DHW cylinder.
Accordingly, the control unit
determines the burner and cylinder
primary pump shutdown point to
prevent the set DHW temperature
being substantially exceeded after
the cylinder has been heated up.
Function description
55