Viessmann FB2B Installation And Service Instructions Manual page 109

Fault codes
(cont.)
Displayed System characteris-
fault code tics
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
E6 Burner blocked
E7 Burner in a fault
state
Cause Measures
Lead break, room Check room temperature
temperature sen- sensor for heating circuit 3
sor, heating circuit and remote control set-
3 (with mixer) tings (see page 143)
Fault external LON Check connections and
subscriber LON subscribers
Ionisation current Check gap between ioni-
too high during cal- sation electrode and
ibration burner gauze assembly
(see page 40).
In open flue mode, pre-
vent very dusty conditions
for the combustion air.
Press reset button R.
Heat transfer too Ensure adequate heat
low during calibra- transfer.
tion. Press reset button R.
Temperature lim-
iter caused shut-
down.
Fault, supply volt- Replace the control unit.
age 24 V
Fault, flame ampli- Replace the control unit.
fier
System pressure Top up with water.
too low
Ionisation current Check ionisation elec-
too low during cali- trode:
bration ■ Distance to burner
■ Contamination of elec-
■ Connecting lead and
Check flue system; rem-
edy flue gas recirculation
if required.
Press reset button R.
Troubleshooting
gauze assembly (see
page 40)
trode
plug-in connections
109