Extensions For External Connections (Accessories) - Viessmann VITOLADENS333-F Service Instructions Manual

Extensions for external connections (accessories)

External extension H1
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)
sÖ Heating circuit pump for the
heating circuit without mixer
sA Cylinder primary pump
sK DHW circulation pump (only for
weather-compensated opera-
tion)
fÖ Power supply
gÖ Central fault message
Function description
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".
aVF External set value 0 to 10 V
aVG KM BUS
85