Control Functions - Viessmann VITODENS 200-W WB2B Service Instructions For Contractors

Extensions for external connections . . .
The external extension is connected
to the boiler control unit via the KM
BUS. The following functions can be
controlled or processed simulta-
neously via the extension:
A ON/OFF switch (on site)
sK DHW circulation pump (only for
weather-compensated opera-
tion)
fÖ Power supply

Control functions

External heating program changeover
The "External heating program chan-
geover" function is connected via
external extension input "aVD". You
can select which heating circuits the
heating program changeover affects
in coding address "91":
Heating program changeover
No changeover
Heating circuit without mixer A1
Heating circuit with mixer M2
Heating circuit without mixer and heating circuit with mixer 91:3
You can select which direction the
heating program changeover takes in
coding address "d5":
Heating program changeover
Changeover towards "Permanently reduced" or "Perma-
nent standby" mode (subject to the selected set value)
Changeover towards "Constant heating mode"
Function description
(cont.)
aVD External blocking
(terminals 2 - 3)
External demand
(terminals 1 - 2)
External heating program
changeover (terminals 1 - 2)
(only for weather-compen-
sated operation)
The allocation of the function
"External heating program
changeover" is set via coding
address "91".
aVG KM BUS
Coding
91:0
91:1
91:2
Coding
d5:0
d5:1
95