Boiler Water Temperature Control; Brief Description - Viessmann Vitotronic 200 Installation And Service Instructions Manual

Function description

Boiler water temperature control

Brief description

The boiler water temperature is
regulated by starting and stopping
the burner or through modulation.
The set boiler water temperature is
determined from the following para-
meters:
Set flow temperature of the sys-
tem circuit (heating circuit A1) or
the heating circuits connected via
the LON
External demand
Set DHW temperature
The set boiler water temperature is
subject to the boiler and the heat-
ing/control versions.
The boiler coding card defaults a
minimum boiler water temperature
that must be maintained to protect
the boiler.
Functions
The boiler water temperature is cap-
tured by the following equipment:
High limit safety cut-out (STB)
(liquid expansion)
TR control thermostat (liquid expan-
sion)
Boiler water temperature sensor
(change in resistance PT 500)
66
In conjunction with Therm-Control:
The set boiler water will be
increased when the actual tempera-
ture at the Therm-Control sensor
falls below the set temperature.
When the DHW cylinder is heated
up, a set boiler water temperature is
defaulted that lies 20 K above the
set DHW temperature (adjustable
via coding address "60").
Coding addresses that influence
the regulation of the boiler water
temperature:
02 to 1C, 60, 99, 9b, 9F, A0 to Fb
For a description, see the coding
overview.
Upper control range limits
High limit safety cut-out STB 110/
100 ºC
Control thermostat TR 95/100/
110 ºC
Electronic maximum temperature
limit:
Setting range: 20 to 127 ºC
Changes via coding address "06"
Lower control limits
In standard mode and when frost
protection is enabled, the boiler
water temperature will be regulated
subject to the respective boiler