Viessmann VITOTRONIC300 Installation And Service Instructions Manual page 75

Vitotronic 300, GW2B Installation and Service
Fault Display
(continued)
Displayed System characteristics Cause
fault code
bF Control mode.
No communication via
LON.
C1 Boiler cools down.
C2 Control mode.
C3 Control mode.
C8 Boiler cools down.
C9 Boiler cools down.
CA Boiler cools down
Cb Boiler cools down
Cd Control mode.
CE Control mode.
Incorrect LON communication module
External safety equipment at plug abÖ Check connection and external safety
Lead break, KM BUS to solar control
module or Vitosolic
Communication fault, extension AM1
Fault, low water
indicator at "X7" of plug-in adaptor 1
for external safety equipment.
Fault, maximum pressure limiter at
"X3" of plug-in adaptor 1 for external
safety equipment.
Fault, minimum or maximum pressure
limiter 2 at "X2" of plug-in adaptor 1
for external safety equipment.
Additional high limit safety cut-out
fault
or
temperature limiter at "X1" of plug-
in adaptor 1 for external safety
equipment.
Vitocom 100 communication fault
Communication fault, plug-in adaptor
1 for external safety equipment
Troubleshooting
Measures
Replace LON communication module.
equipment. (see page 43)
Check KM BUS cable and appliance.
Without solar control unit:
Set code "54:0" in the "General" group.
Check connections.
Without extension AM1:
Set code "32:0" in the "General" group.
Check the system water level of the
system; reset low water indicator
Check system pressure; reset maximum
pressure limiter
Check system pressure, reset minimum
or maximum pressure limiter 2.
Check system temperature; reset high
limit safety cut-out
Check connections and Vitocom 100
(see separate installation and service
instructions).
Without Vitocom 100: Set code "95:0"
in the "General" group.
Check plug-in adaptor
(see page 179).
Without plug-in adaptor:
Set code "30:0" in the "General" group
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