64
Displayed fault
code
System characteristics
Cause
Measures
366, 367
Burner in a fault state
Gas valve power supply
does not turn off.
Replace the HBMU heat manage-
ment unit. See chapter "Replacing
the HBMU heat management unit".
369
Burner in a fault state
Flame is lost immediately
after flame formation (dur-
ing safety time)
Check gas supply (gas pressure
and gas flow switch).
Check balanced flue system for
flue gas recirculation.
Check ionisation electrode for the
following:
■
Clearance to burner gauze as-
sembly
■
Contamination on electrode
Reset the appliance.
370
Burner in a fault state
Gas valve or modulation
valve does not close.
Reset the appliance.
If fault occurs repeatedly, replace
fan unit.
371
Burner in a fault state
Fan speed too low
Check the fan.
Check the fan connecting cables.
Check the fan power supply.
Reset the appliance.
372
Burner in a fault state
Repeated flame loss dur-
ing calibration
■
Check ionisation electrode and
connecting cable.
■
Check plug-in connections for
loose contacts.
■
Check the flue system. Remove
flue gas recirculation if necessa-
ry.
■
Check system for condensate
backup.
■
Visually inspect gas solenoid
valve inlet and inlet strainer for
contamination.
Note
To prevent water damage, detach
fan unit before removing the burn-
er. Deposits on the electrodes indi-
cate foreign bodies in the combus-
tion air.
Check the installation room and
flue system for causes of the de-
posits. For example laundry deter-
gents, cleaning agents, toiletries,
deposits in the ventilation air sup-
ply (chimney). If burner gauze as-
sembly and ionisation electrode
have been replaced, also clean fan
unit, gas/air channel and Venturi
extension.
Reset the appliance.
Troubleshooting
Fault messages
(cont.)
6179762
Diagnosis
