Adjusting Heating Curves - Viessmann Vitodens 222-F Installation And Service Instructions For Contractors

Adjusting heating curves

Only for weather-compensated control units
The heating curves illustrate the relationship between
the outside temperature and the boiler water or flow
temperature.
To put it simply, the lower the outside temperature, the
higher the boiler water or flow temperature.
The boiler water or flow temperature in turn affects the
room temperature.
Settings in the delivered condition:
■ Slope = 1.4
Level = 0
■
90
80
70
60
50
40
30
10
Fig. 45
Slope setting ranges:
■ Underfloor heating systems: 0.2 to 0.8
■ Low temperature heating systems: 0.8 to 1.6
Selecting the set room temperature
Individually adjustable for each heating circuit.
The heating curve is offset along the axis of the set
room temperature. With the heating circuit pump logic
function enabled, the curve modifies the starting and
stopping characteristics of the heating circuit pump.
Slope
5 0 -5 -10 -15 -20
Outside temperature in °C
Commissioning, inspection, maintenance
Note
If the heating system includes heating circuits with mix-
ers, then the flow temperature of the heating circuit
without mixer is higher by a selected differential (8 K in
the delivered condition) than the flow temperature of
the heating circuits with mixers.
The differential temperature is adjustable via coding
address "9F" in the "General" group.
1.4
1.2
1.0
0.8
0.6
0.4
0.2
-25 -30
Standard set room temperature
90
A
C
D
Fig. 46 Example 1: Adjustment of the standard set
room temperature from 20 to 26 °C
Boiler water temperature or flow temperature in °C
A
Outside temperature in °C
B
Set room temperature in °C
C
Heating circuit pump "OFF"
D
Heating circuit pump "ON"
E
Changing the standard set room temperature
Operating instructions
-20
B
E
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