Viessmann Vitocrossal 200 Service Instructions For Contractors page 39

Fault codes
(cont.)
Fault code dis- System characteristics
played
F F4 Flame does not build during
the safety time, no signal re-
ported by the ionisation flame
monitor.
F F4 Flame does not build during
the safety time, no signal re-
ported by the ionisation flame
monitor.
F F4 Flame does not build during
the safety time, no signal re-
ported by the ionisation flame
monitor.
F F5 Air pressure switch 1 reports
no air pressure, fan not run-
ning.
F F5 Air pressure switch 1
switches off during operation
F F6 Gas pressure switch reports
no gas pressure.
F F7 Fan pressure is created dur-
ing the idle state check of air
pressure switch 1.
F F7 Contact of air pressure switch
1 not in idle state
F F8 Flame extinguishes during
operation
F F8 Flame extinguishes during
operation
F F8 Flame extinguishes during
operation
F F9 Fan not running; fan speed
not reached.
F F9 Status duration too long, fan
ramp-up
F F9 Fan speed deviation
F F9 No feedback from fan
Cause
Incorrect gas type selec-
ted
Gas train does not open.
Combustion characteris-
tics not ideal
Air pressure switch 1 faul-
ty, incorrectly connected
or incorrectly set
Flue gas back pressure,
condensate banked up, air
pressure switch 1 hose
faulty, connecting hose
leaking
Gas shut-off valve closed;
gas pressure switch faulty;
multiple problems with gas
supply
Wind influence on fan
Air pressure switch 1 faul-
ty
Incorrect gas type selec-
ted
Burner gauze assembly
faulty
Combustion characteris-
tics not ideal
Fan faulty; cables are faul-
ty or broken
Internal fault; fan cannot
reach its set value.
Fan faulty, cable " a-Ö A"
faulty or broken
Fan faulty, external fan
power supply not connec-
ted or faulty, cable " A"
a-Ö
faulty or broken, fan
blocked (poss. by foreign
bodies)
Troubleshooting
Measures
Adjust gas type (see page 11).
Check connecting cable; check
gas train and replace if required.
Adjust burner setting. If necessary
also adjust the setting screws
when the burner is off to facilitate
the burner start.
Replace air pressure switch 1, con-
nect or adjust correctly.
Remove flue gas back pressure;
check if condensate banked up; re-
set burner control unit; replace
hose.
Open gas shut-off valve; check gas
flow pressure; replace gas filter if
required; reset burner control unit;
replace gas train.
Check the flue draught (stack).
Replace air pressure switch 1.
Adjust gas type (see page 11).
Check the burner gauze assembly.
Replace the burner gauze assem-
bly if it is damaged.
Adjust burner (see from page 16).
Check cables and replace the fan if
required.
Replace fan or burner control unit.
Check cable, replace cable "
or fan if necessary.
Check cable " A", check exter-
a-Ö
nal power supply, replace cable or
fan, remove foreign body.
a-Ö A"
39