External "Mixing Valve Closed"/"Mixing Valve Open; External Heating Program Changeover - Viessmann VITOTRONIC 300 Installation And Service Instructions Manual

Installation, Vitotronic 300-K

External "Mixing Valve Closed"/"Mixing Valve Open"

Legend
A External "Mixing valve open" (floating contact)
B External "Mixing valve closed" (floating contact)

External Heating Program Changeover

Legend
A Floating contact
B Plug aVD of the control unit
Legend
A Floating contact
B Extension EA1
Preselected heating program
(Contact open)
9
or
w
or
w
36
Coding
Central heating OFF/ D5:0
DHW OFF (factory set condition)
D5:1
Central heating
OFF/DHW ON
Central heating
ON/DHW ON
Vitotronic 300, GW5B & MW1B Installation and Service
Connection at plug aVD.
Note: 'Live' contacts lead to short circuits or phase failure.
The external connection must be floating.
Codes
External "Mixing valve
open"
Via coding address "9A"
in the "General" group,
this function is assigned
to the heating circuits.
Connection
Note: 'Live' contacts lead to short circuits or phase
failure. The external connection must be floating.
Connection options:
H Plug aVD
H Extension EA1 (accessory, see page 112)
Codes
Plug aVD
This function is assigned
to the heating circuits via
coding address "91" in the
"General" group.
Changed heating program
(Contact closed)
Permanent operation with reduced room

temperature/DHW OFF
Constant operation with standard room

temperature, DHW in accordance with
coding address "64"
External "Mixing valve
closed"
Via coding address "99"
in the "General" group,
this function is assigned
to the heating circuits.
Extension EA1
Set "5D", "5E" or "5F" in
the "General" group to 1.
This function can be
assigned to the heating
circuits via coding address
"D8" in the "Heating
circuit..." group.