Viessmann Vitodens 333 Service Instructions Manual page 110

Designs
Connection and wiring diagrams
A3 Optolink
A4 Burner control unit
A5 Programming unit
A6 Coding card
A7 Connection adaptor
A8 LON communication module
A9 Internal extension H1
S1 ON/OFF switch
S2 Reset button
X... Electrical interfaces
! Outside temperature sensor
110
external . . .
(cont.)
? Flow temperature sensor, low
loss header
% Cylinder temperature sensor
sÖ Internal circulation pump
sK Primary pump
dG Gas solenoid valve
fÖ Power supply
lH Power supply accessories and
Vitotrol 100
a-Ö Fan motor
aYA Gas governor
aVG KM BUS