Viessmann Vitoligno 300-P Service Instructions For Contractors page 107

Control functions
Control sequence
Mixer circuit
The mixer motor will not be controlled
within the "neutral zone" (±1 K).
Flow temperature drops
(Set value −1 K)
The mixer motor receives the signal
"Mixer open". The signal duration length-
ens with an increasing control differen-
tial. The duration of pauses reduces with
an increasing control differential.
Flow temperature rises
(Set value +1 K)
The mixer motor receives the signal
"Mixer close". The signal duration
lengthens with an increasing control dif-
ferential. The duration of pauses
reduces with an increasing control differ-
ential.
Systems without heating circuit with
mixer at the Vitoligno 300-P
When installing the Vitoligno 300-P as
part of an existing system with sealed
unvented heating circuits with mixer, no
additional mixers need to be fitted to the
Vitoligno 300-P. Coding addresses "02"
and "03" must be set to "0".
(cont.)
Note
If a solar thermal system is connected,
select code "03:2".
For "System circuit" only a few parame-
ters can be set.
System circuit
The system circuit can be regulated as
follows:
■ weather-compensated (with outside
temperature sensor, code "9E:1" is set
automatically)
or
■ with constant boiler water temperature
(without outside temperature sensor,
coding address "9E" must be set to
"0")
Function description
107