Viessmann Vitoladens 300-C Service Instructions Manual page 89

Connection and wiring diagram – internal...
sÖ
Heating circuit pump for the heat-
ing circuit without mixer
sA Circulation pump for cylinder heat-
ing
sK DHW circulation pump
fÖ Power supply [terminals]
gÖ
Central fault message
aXA Oil preheater
aVD ■ External blocking
(terminals 2 - 3)
■ External demand
(terminals 1 - 2)
■ External heating program
changeover (terminals 1 - 2)
(only for weather-compensated
operation)
The allocation of function "Exter-
nal heating program change-
over" is set via coding address
"91".
aVF External set value 0 to 10 V
aVG KM BUS
Designs
(cont.)
89