Viessmann Vitoligno 300-P Service Instructions For Contractors page 115

Control functions
External blocking/external "Mixer
close"
Closing the zero volt contact causes the
burner to perform a regulated shutdown
or the mixer to be closed.
The return temperature raising pump (if
installed) is switched off.
Via coding address "99" (see page 63),
you can determine what input aVD
should affect.
!
Please note
The heating system has no frost
protection when the burner is
switched OFF.
Screed function
The screed function enables screeds to
be dried. For this, always observe the
details specified by the screed manufac-
turer.
When the screed drying function is ena-
bled, the heating circuit pump is switched
ON and the flow temperature is held at
the selected profile. After completion (30
days), the mixer circuit will again be
regulated automatically via the set
parameters. Observe EN 1264. The
report to be provided by the heating con-
tractor must contain the following heat-
up details:
(cont.)
External demand
Closing the zero volt contact starts the
burner subject to load. The boiler water
is heated to the selected set flow tem-
perature that is adjustable via coding
address "9B" (see page 63).
The flow temperature is limited via the
selected set value and the electronic
maximum temperature limiter (coding
address "C6").
■ Heat-up data with respective flow tem-
peratures
■ Max. flow temperature achieved
■ Operating condition and outside tem-
perature during handover
Various temperature profiles are adjust-
able via coding address "F1".
The function continues after power fail-
ure or after the control unit has been
switched OFF. "Heating and DHW" will
be started after the screed drying func-
tion has been terminated or if code
"F1:0" is manually adjusted.
Function description
115