Viessmann Vitodens 050-W Installation And Service Instructions Manual page 63

Fault messages
(cont.)
Displayed fault System characteristics
code
352 Burner in a fault state
353 Shutdown with restart if de-
mand exists
354 Burner in a fault state
355 Burner in a fault state
359 Burner in a fault state
361 Burner in a fault state
364 Burner in a fault state
365 Burner in a fault state
Cause
Combustion CO limit ex-
ceeded
Insufficient gas supply,
burner output reduced
Gas modulation valve tol-
erance outside permissi-
ble range
Analogue signal reference
check: Flame signal is al-
ready present at burner
start.
No ignition spark
Flame signal is not
present or insufficient at
burner start.
Internal fault.
Gas valve relay contact
feedback implausible (re-
lay contact is "welded up")
Troubleshooting
Measures
Check entire flue gas path for the
following:
Leaks
■
Flue gas back pressure caused
■
by water pocket (if flue system
fall is insufficient)
Constrictions
■
Blockages
■
Repair flue system if necessary.
Reset the appliance.
Check the gas supply.
Visually inspect gas solenoid valve
inlet strainer for contamination.
Reset the appliance.
Replace gas fan unit.
Replace the HBMU heat manage-
ment unit. See chapter "Replacing
the HBMU heat management unit".
Check whether the ignition elec-
■
trode insulation is damaged.
Check for a voltage of 230 V∼ at
■
the ignition module during the ig-
nition phase. If not, replace the
HBMU heat management unit.
If 230 V~ is present at the igni-
■
tion module but there is still a
fault, replace the ignition module.
Check connecting cables and
■
leads from ignition module and
ignition electrode.
Reset the appliance.
Check ionisation electrode and
connecting cable. Check plug-in
connections for loose contacts.
Note
Deposits on the electrodes indicate
foreign bodies in the combustion
air. Check the installation room and
flue system for causes of the de-
posits. For example: Laundry de-
tergents, cleaning agents, toilet-
ries, deposits in the ventilation air
supply (chimney)
Reset the appliance.
Replace the HBMU heat manage-
ment unit.
Replace the HBMU heat manage-
ment unit.
63