Viessmann VITOLIGNO 300-C Installation And Service Instructions Manual page 179

Control functions
(cont.)
Extended economy mode
The heating circuit pump is switched off and the set
flow temperature is set to 0 °C if one of the following
criteria is met:
The outside temperature exceeds the value selected
■
via coding address "A6".
The set room temperature is reduced via coding
■
address "A9".
Flow temperature control
90
80
70
60
50
40
30
10
Fig. 108
Example for outside temperature of -14 °C:
Underfloor heating system, slope 0.2 to 0.8
A
Low temperature heating system, slope 0.8 to 1.6
B
C Heating system with a boiler water temperature in
excess of 75 °C, slope 1.6 to 2.0
Upper control range limit
Electronic maximum temperature limit
Setting range: 10 to 100 °C
Change via coding address "C6"
Note
The maximum temperature limit is no substitute for the
underfloor heating system temperature limiter.
■
■
Frost protection
If the outside temperature falls below +1 °C, a flow
temperature of at least 10 °C is ensured. For changes,
see coding address "A3", variable frost protection limit
Slope
0 -10 -20
-14
Outside temperature in °C
Temperature limiter for underfloor heating:
If the selected value is exceeded, the temperature lim-
iter stops the heating circuit pump. The flow tempera-
ture is only slowly reduced in this situation, i.e. it may
be several hours before the system restarts automati-
cally.
Lower control range limit
Electronic minimum temperature limit
Setting range: 10 to 100 °C
Change via coding address "C5"
Only enabled during operation with standard room
temperature
The mixer has been closed for 12 min. (mixer econ-
omy function, coding address "A7").
The actual room temperature exceeds the value
selected via coding address "B5".
1.4
C
1.2
1.0
B
0.8
0.6
0.4
A
0.2
-30
Function description
179