Extensions For External Connections (Accessories) - Viessmann VITODENS 343-F WS4A Installation And Service Instructions Manual

Extensions for external connections (accessories)

Internal extension H2
The internal extension is integrated
into the control unit housing. The fol-
lowing alternative functions can be
connected to relay output sK. The
function is allocated via coding
address "53":
Central fault message (coding
address "53:0")
DHW circulation pump (coding
address "53:1") (only for weather-
compensated operation)
Function description
Heating circuit pump for heating cir-
cuit without mixer (coding address
"53:2")
Cylinder primary pump (coding
address "53:3")
An extractor can be switched OFF via
connection aBJ when the burner
starts.
117