Viessmann Vitocrossal 300 CA3 2.5 Installation And Service Instructions Manual page 197

Vitocrossal 300 CA3 Series 2.5 to 6.0 Installation/Service
Fault Codes
(continued)
Displayed System Characteristics
Fault Code
No flame formation during
F F4
safety time; ionization flame
monitor reports no flame signal
No flame formation during
F F4
safety time; ionization flame
monitor reports no flame signal
Poor start-up characteristics,
F F4
rotary damper does not close,
solenoid valve does not switch
No flame builds during safety
F F4
time; ionization flame monitor
reports no signal
No flame builds during safety
F F4
time; ionization flame monitor
reports no signal
No flame builds during safety
F F4
time; ionization flame monitor
reports no signal
Air pressure switch 1, LDW1
F F5
shows no air pressure, fan does
not operate
Air pressure switch 1, LDW1
F F5
switches off during operation
Gas pressure switch 1, GDW1
F F6
shows no gas pressure
Fan pressure is created during
F F7
the idle state check of air
pressure switch 1, LDW1
Contact of air pressure switch
F F7
1, LDW1 not closed in idle
state
Flame extinguishes during
F F8
operation
Flame extinguishes during
F F8
operation
Cause
Ignition electrode not set
correctly; electrodes grounded;
ignition unit faulty; burner control
unit faulty
Insulation body of ignition or
ionization electrode cracked
Servomotor faulty, servomotor
connecting cable faulty, solenoid
valve faulty, burner control unit
output relay faulty
Incorrect gas type selected
Gas valve does not open
Combustion characteristics not
ideal
Air pressure switch 1, LDW1
faulty, incorrectly connected or
incorrectly set
Flue gas back pressure;
condensate built up; air pressure
switch 1, LDW1 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, LDW1
faulty
Burner gauze assembly faulty
Combustion characteristics not
ideal
Burner Control Unit
Measures
Adjust ignition electrodes (see page
114); replace ignition unit; replace
burner control unit
Replace ignition or ionization
electrode
Replace connecting cable; replace
servomotor; replace solenoid
valve; replace burner control unit
Adjust gas type (see page 190)
Check the connecting cable;
check the gas valve and replace
if required
Adjust the burner (see pages 93
and 94, if necessary, also adjust
the setting screws when the
burner is OFF to be able to start
the burner)
Replace air pressure switch 1,
connect or set correctly
Remove flue gas back pressure;
check if condensate banked up;
reset 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 valve
Check flue outlet or (chimney)
Replace air pressure switch 1,
LDW1
Check burner gauze assembly;
replace if damaged
Adjust burner (see pages 93 and 94)
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