Viessmann Vitocrossal 300 Service Instructions For Contractors page 100

Troubleshooting
Fault codes
(cont.)
Displayed System characteris-
fault code tics
dd Control mode without
room influence
dE Control mode without
room influence
dF Control mode without
room influence
E0 Control mode
E1 Burner in a fault
state
E3 Burner in a fault
state
E4 Burner blocked
E5 Burner blocked
100
Cause
Lead break, room
temperature sen-
sor, heating circuit
1 (without mixer)
Lead break, room
temperature sen-
sor, heating circuit
2 (with mixer)
Lead break, room
temperature sen-
sor, heating circuit
3 (with mixer)
Fault external LON
subscriber
Ionisation current
too high during cal-
ibration
Heat transfer too
low during calibra-
tion.
Temperature lim-
iter caused shut-
down.
Fault, supply volt-
age 24 V
Fault, flame ampli-
fier
Measures
Check room temperature
sensor for heating circuit 1
and remote control set-
tings (see page 125)
Check room temperature
sensor for heating circuit 2
and remote control set-
tings (see page 125)
Check room temperature
sensor for heating circuit 3
and remote control set-
tings (see page 125)
Check connections and
LON subscribers
Check gap between ioni-
sation electrode and
burner gauze assembly
(see page 21).
In open flue mode, pre-
vent very dusty conditions
for the combustion air.
Press reset button R
Ensure adequate heat
transfer.
Press reset button R
Replace control unit
Replace control unit