Viessmann Vitovalor PT2 E11T Installation And Service Instructions Manual page 110

Troubleshooting
Fault messages for gas condensing module
Fault number System characteristics
on the display
F.351 Burner in a fault state
F.352 Burner in a fault state
F.353 Burner locked out
F.354 Burner in a fault state
F.355 Burner in a fault state
110
(cont.)
Cause
Ionisation current check
CO limit within appliance
exceeded
Retraction function
Gas train faulty, modula-
tion valve control faulty or
flue gas path blocked
Flame signal is already
present at burner start.
Measures
Check ignition electrodes and con-
necting cables.
Check ionisation electrode and
connecting cable.
Reset burner.
Check entire flue gas path for the
following:
Flue gas recirculation
■
Leaks
■
Flue gas back pressure caused
■
by water pocket (if flue system
fall is insufficient)
Constrictions
■
Blockages
■
Repair flue system if necessary.
Reset burner.
Check ignition electrodes and con-
necting cables.
Check ionisation electrode and
connecting cable.
Reset burner.
Check connecting cables to the
gas train for damage.
Check gas train.
Check flue system for blockages or
constrictions.
Reset burner.
Check system for condensate
backup.
Note
To prevent water damage, detach
fan unit before removing the burn-
er.
Check ionisation and ignition elec-
trode for damage and earth faults
(e.g. contact with the thermal insu-
lation ring).
Check connecting cables from ioni-
sation and ignition electrode.
Test static gas pressure and gas
flow pressure. Check that on-site
gas line and gas flow switch are
correctly sized.
Note
If the building pressure regulator
has a leak, you may notice rising
pressure when the burner is idle.
When the system is restarted, the
gas flow switch may trip.
Reset burner.