External Extension H - Viessmann Vitodens 333-F Service Instructions Manual

External extensions for external connections . . .

External extension H2

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
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
107