Viessmann Vitocrossal 200 Service Instructions For Contractors page 53

Fault codes
(cont.)
Displayed System characteris-
fault code tics
F F8 Flame tears off dur-
ing operation
F F9 Fan not running; fan
speed not reached
F F9 Status duration too
long, fan ramp-up
F F9 Varying fan speed
F F9 No fan feedback
F FA Fan runs without de-
mand; burner control
unit in a fault state
F Fb Burner does not start Excessive com-
Cause
Combustion char-
acteristics not ide-
al
Fan faulty; cables
are faulty or bro-
ken
Internal fault; fan
cannot reach its set
value
Fan faulty, cable
"a-ÖA" faulty or
broken. Check ca-
ble "a-ÖA"; check
external power
supply; replace the
cable or fan; re-
move foreign bod-
ies
Fan faulty, external
fan power supply
not connected or
faulty "a-ÖA" or
cable faulty or bro-
ken, fan blocked
(poss. by foreign
bodies)
Fan does not reach
idle state, cable
"a-ÖA" faulty, fan
faulty, faulty burner
control unit
bustion chamber
pressure (LDW2);
flue gas path or
condensate path
blocked
Troubleshooting
Measures
Adjust burner (see from
page 19)
Check cables; replace fan
if required
Replace fan or burner
control unit
Check cable, possibly re-
place cable "a-ÖA" or
fan
Check cable "a-ÖA",
check external power
supply, replace cable or
fan, remove foreign bod-
ies
Fan subject to wind influ-
ence, check flue outlet
and fan, replace cable
"a-ÖA", replace fan, re-
place burner control unit
Check condensate drain
and flue gas path for
blockages
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