Viessmann VITODENS 111-W Installation And Service Instructions Manual page 76

Troubleshooting
Fault messages
(cont.)
Displayed fault System characteristics
code
184 Burner in a fault state
185 Burner in a fault state
299 Date/time wrong
345 Burner locked out, automatic
enabling after appliance cool-
down. Independent restart
346 Burner in a fault state
347 Burner in a fault state
348 Burner in a fault state
76
Cause
Short circuit, flow temper-
ature sensor/high limit
safety cut-out
Lead break, flow tempera-
ture sensor/high limit safe-
ty cut-out
Real-time clock fault
Temperature limiter has
responded.
Ionisation current calibra-
tion error
Flue gas recirculation
Gas modulation valve
Measures
Check the flow temperature sen-
sor/high limit safety cut-out.
Check sensor lead. Replace faulty
component if required.
Reset the appliance.
Check the flow temperature sen-
sor/high limit safety cut-out. Re-
place faulty component if required.
Reset the appliance.
Check the date and time; amend if
necessary.
Ensure adequate heat transfer.
■
Check heating system fill level.
■
Check pre-charge pressure in di-
■
aphragm expansion vessel. Ad-
just to required system pressure.
Check whether flow rate is suffi-
■
cient (circulation pump).
Check function of 3-way diverter
■
valve. Vent the system.
If the fault occurs during DHW
heating: Check DHW cylinder or
plate heat exchanger for contami-
nation and scaling.
Check the gas supply pressure.
■
Check gas solenoid valve strain-
■
er on the inlet side for contami-
nation.
Check ionisation electrode for
■
contamination.
Check flue system. Remove flue
■
gas recirculation if required.
Check the condensate drain
■
(condensate blockage).
Reset the appliance.
Check the flue system for leaks;
■
remedy if necessary.
Check the flue system for flue
■
gas back pressure, e.g. caused
by an insufficient fall in the flue
system, constrictions or block-
ages. Rectify if necessary.
Reset the appliance.
If several heat generators are con-
nected to a common flue system:
Check whether "Multiple connec-
tions" is set in the commissioning
assistant.
Check the flue system for unre-
stricted flow.
If fault remains, replace gas fan
unit.