Viessmann Vitotronic 300 Installation And Service Instructions Manual page 50

Function Description
Heating Circuit Control Unit
Room temperature
In conjunction with the remote control and room
temperature hook-up (coding address "B0" in the
"Heating circuit..." group): Compared with the outside
temperature, the room temperature has a greater
influence on the set boiler water temperature (changed
via coding address "B2" in the "Heating circuit..." group).
In conjunction with heating circuits with mixing valve:
For control differentials (actual value deviation) above
2 K room temperature, the influence can be increased
again (coding address "B6" in the "Heating circuit..."
group):
Quick heat-up
The set room temperature must be raised by at least
2K by the following measures:
– Activating party mode
– Changing from central heating with reduced
temperature to central heating with standard
temperature
– Start optimization (coding address "B7" in the
"Heating circuit..."group)
Quick heat-up will stop when the set room temperature
has been reached.
Quick setback
The set room temperature must be reduced by at
least 2 K by the following measures:
– Activating economy mode
– Changing from central heating with standard
temperature to central heating with reduced
temperature
– Stop optimization (coding address "C1" in the
"Heating circuit..." group)
Quick setback ends when the set room
temperature has been reached.
50
(continued)
Heating circuit pump logic – Economy circuits
The heating circuit pump is switched off
[set supply temperature set to 32° F (0° C)] if one
of the following criteria is met:
The outside temperature exceeds the value selected
via coding address "A5" in the "Heating circuit..."
group.
The adjusted outside temperature exceeds the
value selected via coding address "A6" in the
"Heating circuit..." group.
The mixing valve has been attempting to close for
more than 12 min. (mixing valve economy function,
coding address "A7" in the "Heating circuit..." group).
The duration of the pump idle time selected via
coding address "A9" in the "Heating circuit..." group
has been reached.
Precondition:
– There is no risk of frost.
– Coding address "B0" in the "Heating circuit..."
group must be set to 0.
Note: If, during the pump idle time, the system is
The actual room temperature exceeds the value
selected via coding address "B5" in the "Heating
circuit..." group.
Vitotronic 300, GW5B Installation and Service
switched to heating mode or the set room
temperature is increased, the heating circuit
pump is switched ON, even if the time has not
yet elapsed.