Viessmann Vitodens 333 Service Instructions Manual page 78

Troubleshooting
Fault codes
(cont.)
Display Const. Weath.
fault comp.
code
Ed X X
F0 X X
F1 X X
F2 X X
F3 X X
F4 X X
F8 X X
78
System char- Cause
acteristics
Burner control Internal fault
unit fault
Burner Internal fault
blocked
Burner control Flue gas
unit fault temperature
limiter has
responded
Burner control The tem-
unit fault perature lim-
iter has
responded
Burner control Flame signal
unit fault is already
present at
burner start
Burner control No flame sig-
unit fault nal
Burner control The fuel
unit fault valve closes
too late
Remedy
Replace the con-
trol unit
Replace the con-
trol unit
Check flue gas
path/route; press
"E"
Check the heating
system fill level,
the circulation
pump, the tem-
perature limiter
and interconnect-
ing cables/leads;
vent the system;
press "E"
Check the ionisa-
tion electrode and
interconnecting
leads; press "E"
Check the ionisa-
tion electrode,
ignition, ignition
module, intercon-
necting cables
and leads, gas
pressure, gas
combination valve
and the ionisation
current; press
"E"
Check the gas
combination valve
and both control
paths; press "E"