62
Displayed fault
code
System characteristics
Cause
Measures
184
Burner in a fault state
Short circuit, flow temper-
ature sensor/high limit
safety cut-out
Check the flow temperature sen-
sor/high limit safety cut-out.
Check sensor lead. Replace faulty
component if necessary.
Reset the appliance.
299
Date/time wrong
Real-time clock fault
Check time and date and set if
necessary.
346
Burner in a fault state
Ionisation current calibra-
tion error
■
Check the gas supply pressure.
■
Check gas solenoid valve inlet
strainer for contamination.
■
Check ionisation electrode for
contamination.
■
Check the flue system. Remove
flue gas recirculation if necessa-
ry.
■
Check the condensate drain
(condensate backup).
Reset the appliance.
347
Burner in a fault state
Flue gas recirculation
Remove flue gas recirculation.
Check entire flue gas path for the
following:
■
Flue gas back pressure caused
by water pocket (if flue system
fall is insufficient), constriction,
blockage.
■
Repair flue system if necessary.
Reset the appliance.
348
Burner in a fault state
Gas modulation valve
If several heat generators are con-
nected to a common flue system:
Check whether
"Multiple connec-
tion"
is set in the commissioning
assistant.
Check the flue system for unre-
stricted flow.
If fault remains, replace gas fan
unit.
349
Burner in a fault state
Air mass rate flow not de-
tected correctly in fan unit.
■
Check for dust contamination in
the ventilation air.
■
Check burner gauze assembly
for contamination.
Reset the appliance. If the fault oc-
curs repeatedly, replace the gas
fan unit.
350, 351
Burner in a fault state
Ionisation current lies out-
side the permissible range
Replace the HBMU heat manage-
ment unit. See chapter "Replacing
the HBMU heat management unit".
Troubleshooting
Fault messages
(cont.)
6179762
Diagnosis
