Viessmann C3TB, Installation And Service Instructions For Contractors

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119
Fault code dis-
played System characteristics Cause Measures
CF Control mode
No communication via LON Communication error,
LON communication mod-
ule Check LON communication mod-
ule and replace if required.
If no LON communication module
is installed, set code "76:0" in
"General" group.
d6 Control mode Input DE1 at EA1 exten-
sion reports a fault. Remedy fault at appliance con-
cerned.
d7 Control mode Input DE2 at EA1 exten-
sion reports a fault. Remedy fault at appliance con-
cerned.
d8 Control mode Input DE3 at EA1 exten-
sion reports a fault. Remedy fault at appliance con-
cerned.
dA Control mode without room
influence Short circuit, room tem-
perature sensor, heating
circuit 1 (without mixer) Check room temperature sensor,
heating circuit 1.
db Control mode without room
influence Short circuit, room tem-
perature sensor, heating
circuit 2 (with mixer) Check room temperature sensor,
heating circuit 2.
dC Control mode without room
influence Short circuit, room tem-
perature sensor, heating
circuit 3 (with mixer) Check room temperature sensor,
heating circuit 3.
dd Control mode without room
influence Lead break, room temper-
ature sensor, heating cir-
cuit 1 (without mixer) Check room temperature sensor,
heating circuit 1 and remote control
configuration (see page 175).
dE Control mode without room
influence Lead break, room temper-
ature sensor, heating cir-
cuit 2 (with mixer) Check room temperature sensor,
heating circuit 2 and remote control
configuration (see page 175).
dF Control mode without room
influence Lead break, room temper-
ature sensor, heating cir-
cuit 3 (with mixer) Check room temperature sensor,
heating circuit 3 and remote control
configuration (see page 175).
E0 Control mode External LON subscriber
error Check connections and LON sub-
scribers.
E1 Burner in a fault state Ionisation current too high
during calibration Check gap between ionisation
electrode and burner gauze as-
sembly (see page 78).
In open flue operation, prevent
high levels of dust in the combus-
tion air.
Press reset
R .
E2 Burner in a fault state Heat transfer too low dur-
ing calibration. Ensure adequate heat transfer.
Press reset
R .
E3 Burner in a fault state Heat transfer too low dur-
ing calibration.
Temperature limiter has
shut down. Ensure adequate heat transfer.
Press reset
R .
E4 Burner blocked 24 V power supply fault Replace control unit.
E5 Burner blocked Flame amplifier fault Replace control unit.
E6 Burner blocked System pressure too low Top up with water.
Troubleshooting
Fault codes for gas condensing module
(cont.)
5775 636 GB
Diagnosis