Viessmann VITOLIGNO 300-C Operating Instructions Manual page 48

Maintenance
Terminology
(continued)
48 48
Heating curve
Heating curves illustrate the relationship between the
outdoor temperature, room temperature (set value) and
boiler water or (heating circuit) supply temperature.
The lower the outdoor temperature, the higher the
boiler water or (heating circuit) supply temperature.
In order to guarantee sufficient heat and minimum fuel
consumption at any outdoor temperature, the conditions
of your building and your heating system must be taken
into consideration. The heating curve is set by your
heating contractor for this purpose.
Note: If your heating system includes heating circuits
with mixing valves, then the supply temperature
for the heating circuit without mixing valves is
higher by a selected differential than the supply
temperature for the heating circuits with mixing
valves.
The illustrated heating curves apply with the following
settings:
H Heating curve shift = 0
H Standard room temperature (set value) = 68°F (20ºC)
Example:
For outdoor temperature 5°F (-15°C):
A Underfloor heating system, slope 0.2 to 0.8
B Low temperature heating system, slope 0.8 to 1.6
C Heating system with a boiler water temperature in
excess of 167°F (75°C), slope 1.6 to 2.0
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.
Vitoligno 300-C Operating