Viessmann VITODENS 343-F WS4A Installation And Service Instructions Manual page 96

Troubleshooting
Fault codes
(cont.)
Fault code System character-
on the dis- istics
play
dA Control mode with-
out room influence
db Control mode with-
out room influence
dd Control mode with-
out room influence
dE Control mode with-
out room influence
E4 Burner blocked
E5 Burner blocked
E8 Burner in a fault
state
E9 Burner in a fault
state
96
Cause Measures
Room tempera- Check the room tem-
ture sensor, heat- perature sensor, heating
ing circuit A1 circuit A1.
shorted out
Room tempera- Check the room tem-
ture sensor, heat- perature sensor, heating
ing circuit with circuit with mixer M2.
mixer M2 shorted
out
Room tempera- Check the room tem-
ture sensor, heat- perature sensor, heating
ing circuit A1 lead circuit A1 and the re-
broken mote control DIP switch
settings (see page 126)
Room tempera- Check the room tem-
ture sensor, heat- perature sensor, heating
ing circuit with circuit with mixer M2
mixer M2 lead and the remote control
broken DIP switch settings (see
page 126)
Internal fault Replace the control unit.
Internal fault Check the ionisation
electrode and cables.
Check the flue gas sys-
tem for soundness.
Press "E RESET"; re-
place the control unit, if
required.
The ionisation Check the ionisation
current lies out- electrode and cable.
side the permissi- Press "E RESET".
ble range
The ionisation Check the ionisation
current lies out- electrode and cable.
side the permissi- Press "E RESET".
ble range during
calibration