Viessmann VITOTRONIC 100 GC1 Installation And Service Instructions Manual page 103

Diagnosis
(continued)
Faults with fault display on the programming unit (continued)
Fault
Behaviour of system
code in
display
c4
Control mode
c8
Boiler cools down
c9 Boiler cools down
ca Boiler cools down
cb
Boiler cools down
cd
Controlled operation
cE e
Controlled operation
cf Controlled operation
d1
Boiler cools down
d4
Boiler cools down
d6 Controlled operation
d7 Controlled operation
d8
Controlled operation
e0
Controlled operation
Cause of fault
Faulty communication with Input
Module
0 to 10 V
Error
Low water indicator
Error
Maximum pressure limiter
Error
Minimum pressure limiter or
maximum pressure limiter 2
Error
Additional fixed high limit or limit
thermostat or flue gas damper
Communication error
Vitocom
Communication error
Plug-in adaptor for external
safety equipment
Error
LON communication module
Burner fault
Fixed high limit has operated
Fault at "DE1" in the plug-in
adaptor for external safety
equipment
Fault at "DE2" in the plug-in
adaptor for external safety
equipment
Fault at "DE3" in the plug-in
adaptor for external safety
equipment
Open circuit
LON communication module
Troubleshooting
Action
Check connections and
cables/leads; replace Input
Module, if required
(see page 126)
Without Input Module:
Set coding 9d: 0
Check water level of system,
reset low water indicator
Check system pressure, reset
maximum pressure limiter
Check system pressure, reset
minimum or maximum pressure
limiter
Check system pressure, reset
fixed high limit or flue gas
damper
Check connections and
Vitocom
Replace communication
module
Check burner
Check fixed high limit reset to
25° C (+/- 5.0° C)
Cooler than the high limit set
Check connection at inputs
"DE1" to "DE3"
Check connection
103