Viessmann VITODENS 242-F Installation And Service Instructions Manual page 135

Fault codes
(cont.)
Displayed System characteris-
fault code tics
F0 Burner blocked
F1 Burner in a fault
state
F2 Burner in a fault
state
F3 Burner in a fault
state
F7 Burner blocked
F8 Burner in a fault
state
F9 Burner in a fault
state
FA Burner in a fault
state
FC Burner in a fault
state
Fd Burner in a fault state
and additional fault
b7 is displayed
Cause
Internal fault
Flue gas tempera-
ture limiter has re-
sponded.
Temperature limit-
er has responded.
Flame signal is al-
ready present at
burner start.
Short circuit or lead
break, water pres-
sure sensor
Fuel valve closes
too late.
Fan speed too low
during burner start
Fan not in idle
state
Gas train faulty,
faulty modulation
valve control or flue
gas path blocked
Boiler coding card
is missing
Troubleshooting
Measures
Replace control unit.
Check heating system fill
level. Vent the system.
Press reset button R after
flue system has cooled
down.
Check heating system fill
level. Check circulation
pump. Vent the system.
Check temperature limiter
and connecting cables.
Press reset button R.
Check ionisation elec-
trode and connecting ca-
ble.
Press reset button R.
Check the water pressure
sensor and the connect-
ing cable.
Check gas train. Check
both control paths.
Press reset button R.
Check fan, fan connecting
cables and power supply;
check fan control.
Press reset button R.
Check fan, fan connecting
cables and fan control.
Press reset button R.
Check gas train. Check
flue system.
Press reset button R.
Insert the boiler coding
card.
Press reset button R.
Replace control unit if
fault persists.
135