Viessmann Vitodens 200-W Installation Instructions Manual page 147

Internal extensions (accessories)
The internal extension is integrated into
the control unit casing. The following
alternative functions can be connected
to relay output sK. The function is
assigned via coding address "53" in
group "General":
■ Central fault message (code "53:0")
■ DHW circulation pump (code "53:1")
(only for weather-compensated oper-
ation)
Function description
(cont.)
■ Heating circuit pump for heating circuit
without mixer (code "53:2")
■ Circulation pump for cylinder heating
(code 53:3)
An extractor fan can be switched off via
connection aBJ when the burner starts.
147