Cylinder Temperature Control - Viessmann VITOTRONIC 100 Installation And Service Instructions Manual

Function description
Heating circuit control
DHW heating with priority control:
The heating circuit pump is
switched OFF.
DHW heating without priority con-
trol:
The heating circuit pump remains
switched ON.
The boiler water temperature for
DHW cylinder heating is also
passed onto the heating circuit.
Burner and heating circuit pump con-
trol:
Room thermostat Vitotrol 100,
type UTD at plug a-D:
The burner will be switched ON or

Cylinder temperature control

Brief description
The cylinder thermostat operates
with a constant temperature. It is the
result of starting and stopping the
cylinder primary pump.
The switching differential is ±2.5 K.
When the DHW cylinder is being
heated up, a set boiler water tem-
perature is defaulted that lies 20 K
above the set DHW cylinder tem-
perature (adjustable via coding
address 60).
Functions
Frost protection:
The DHW cylinder will be heated to
20 ºC if the DHW temperature falls
below 10 ºC.
34
(cont.)
OFF by the Vitotrol 100, type UTD;
the heating circuit pump runs con-
stantly (code 01:0).
The burner and heating circuit
pump will be switched ON or OFF
via the Vitotrol 100, type UTD;
heating circuit pump with run-on
(code 01:1).
External burner start via plug X12:
The heating circuit pump will only
run, if the burner starts under exter-
nal control.
Heating circuit pump with run-on
(code 01:2)
During cylinder heating, central
heating is switched OFF (optional
cylinder priority control).
Coding addresses that influence
the cylinder temperature control:
55, 56, 58, 60 to 63, A2.
For a description, see the coding
overview.