Viessmann Vitotronic 300-K Operating Instructions Manual page 44

Additional Information
Terminology
(continued)
Outside temperature
A Changing the slope:
The steepness of the heating curve changes
B Changing the shift:
The heating curves are shifted in parallel in a vertical
direction
Heating circuit
A heating circuit is a sealed circuit between the boiler and
radiators, in which the heating water circulates.
A heating system may comprise several heating circuits.
For example, one heating circuit for the rooms occupied
by you and one heating circuit for the rooms of a separate
apartment.
44
Vitotronic 200 and 300-K Operating
Heating circuit pump
Circulation pump for the circulation of the heating water
in the heating circuit.
Actual temperature
Current temperature at the time of the scan; e.g. actual
DHW temperature.
Mixing valve
A mixing valve mixes the water heated in the boiler
with the cooled water returning from the heating circuit.
The water, heated to the right temperature in line with
demand, is pumped to the heating circuit by the heating
circuit pump. The control unit adjusts the heating circuit
supply temperature via the mixing valve to the various
conditions, e.g. different outside temperature.
Night setback
See "Reduced heating mode".
Standard heating mode
When you are in the house during the day, you can heat
the rooms in standard heating mode. Set the periods
using the time program for central heating. During these
periods, the rooms are heated to the standard room
temperature.