Viessmann VITODENS 333 Service Instructions Manual page 80

Troubleshooting
Checking and acknowledging faults
Fault code Const.
in the dis-
play
dd
dE
E4 X
E5 X
E6 X
F0 X
F1 X
80
Weat- System
h. character-
comp. istics
X
X
X Burner
blocked
X Burner
blocked
X Burner in
fault state
X Burner
blocked
X Burner in
fault state
(cont.)
Cause Remedy
Room temperature Check the
sensor heating cir- room tem-
cuit A1 lead break perature sen-
sor - heating
circuit A1
Heating circuit M2 Check the
room temperature room tem-
sensor lead break perature sen-
sor - heating
circuit M2
Fault - supply vol- Replace con-
tage trol unit
Internal error Check the
ionisation
electrode and
leads. Check
flue gas sys-
tem for
soundness.
Press E.
Flue gas/air supply Check the
system blocked flue gas/air
supply sys-
tem. Check
the differen-
tial pressure
sensor.
Press E.
Internal error Replace con-
trol unit
Flue gas tempera- Check the
ture limiter has heating sys-
responded tem water
level. Vent
the heating
system.
Press reset
E no sooner
than after
20 minutes.