Viessmann MatriX Service Instructions For Contractors page 27

Fault codes
(cont.)
Fault code on System characteristics
display
F F4 Flame does not form during
safety time, no signal repor-
ted by ionisation flame moni-
tor.
F F4 Flame does not form during
safety time, no signal repor-
ted by ionisation flame moni-
tor.
F F4 Flame does not form during
safety time, no signal repor-
ted by ionisation flame moni-
tor.
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 Deviating fan speed
F F9 No fan feedback
Cause
Incorrect gas type selec-
ted
Gas train does not open.
Combustion parameters
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 parameters
not ideal
Fan faulty; cables are faul-
ty or broken
Internal fault; fan cannot
reach its set value.
Fan faulty, cable " A"
a-Ö
faulty or broken
Fan faulty, external power
supply to fan not connec-
ted or faulty, cable " a-Ö A"
faulty or broken, fan
blocked (poss. by foreign
body).
Troubleshooting
Measures
Adjust gas type (see page 7)
Check connecting cable; check
gas train and replace if required.
Adjust the burner (see from
page 12; 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 outlet (chimney).
Replace air pressure switch 1.
Adjust gas type (see page 7)
Check burner gauze assembly; re-
place if damaged.
Adjust burner (see from page 12)
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"
a-Ö
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