Viessmann VITOTRONIC 100 GC1 Installation And Service Instructions Manual page 129

Wiring Diagrams
Line voltage motherboard (continued)
sÖ Control output
sA DHW pump
sL Shunt pump or boiler circuit pump
fÖ Power supply connection,
120 VAC
fA Burner connection
gÖ Compiled failure alarm
gS Boiler isolation valve
or
Boiler return valve
(continued)
lÖ Burner (2nd stage/modulating)
aBÖ External equipment
a External safety equipment
(remove jumper when
connecting)
b External controlled switch-off
(remove jumper when
connecting)
c External burner activation
aBA Safety circuit - emergency
shut-off
aBH Power supply connection for
accessories
Additional information
F1, F2 Fuses
F6 Fixed high limit "E"
120°C (99°C or 110°C) /
248°F (210°C or 230°F)
F7 adjustable high limit "R"
95°C (100°C or 110°C)
203°F (212°F or 230°F)
K1-K10 Relay
S1 Heating system on/off
switch "8"
S2 TUV button
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