Adjusting The Heating Curves - Viessmann Vitocrossal 300 Service Manual

Vitocrossal 300 CU3A 26 to 57 Service

Adjusting the Heating Curves

The heating curves illustrate the relationship between
the outdoor temperature and the boiler water or supply
temperature.
To put it simply, the lower the outside temperature, the
higher the boiler water or supply temperature.
The room temperature, again, depends on the boiler water
or the supply temperature.
Note: If the heating system includes heating circuits with
mixing valves, then the supply temperature of the
heating circuit without mixing valve is higher by a
selected differential (8 K in the delivered condition)
than the supply temperature of the heating circuits
with mixing valves. The differential temperature can
be changed at coding address 9F.
Settings in the delivered condition:
Slope = 1.4

Shift = 0

Legend
A Heating curve slope for underfloor heating systems
B Heating curve slope for low temperature heating
systems
C High temperature heating system, e.g. fintube
radiation, fan coils
Changing the slope and shift
Legend
A Changing the slope
B Changing the shift (vertical parallel offset of the
heating curve)
Extended menu:
1. å
2. "Heating"
3. Select heating circuit.
4. "Heating curve"
5. "Slope" or "Shift"
6. Select heating curve according to the system
requirements.
Service
45