Viessmann VITODENS 100-W Installation And Service Instructions Manual page 57

Fault messages
(cont.)
Displayed fault System characteristics
code
396 Burner in a fault state
399 Burner in a fault state
400 Burner in a fault state
401 Burner in a fault state
402 Burner in a fault state
403 Burner in a fault state
404 Burner in a fault state
405 Burner in a fault state
406, 408, 410 Burner in a fault state
416 Burner locked out
417, 418 Burner in a fault state
Cause
HBMU heat management
unit faulty
IO electrode earth fault,
HBMU heat management
unit faulty
HBMU heat management
unit faulty
IO electrode earth fault,
HBMU heat management
unit faulty
HBMU heat management
unit faulty
Ionisation electrode earth
fault, HBMU heat man-
agement unit faulty
HBMU heat management
unit faulty
Ionisation electrode earth
fault, HBMU heat man-
agement unit faulty
HBMU heat management
unit faulty
Flue gas temperature sen-
sor incorrectly positioned
HBMU heat management
unit faulty
Troubleshooting
Measures
Replace the HBMU heat manage-
ment unit. See chapter "Replacing
the HBMU heat management unit".
Reset the appliance.
Check IO electrode for earth fault.
If the fault persists, replace the
HBMU heat management unit. See
chapter "Replacing the HBMU heat
management unit".
Reset the appliance.
Replace the HBMU heat manage-
ment unit. See chapter "Replacing
the HBMU heat management unit".
Reset the appliance.
Check IO electrode for earth fault.
If the fault persists, replace the
HBMU heat management unit. See
chapter "Replacing the HBMU heat
management unit".
Reset the appliance.
Replace the HBMU heat manage-
ment unit. See chapter "Replacing
the HBMU heat management unit".
Reset the appliance.
Check IO electrode for earth fault.
If the fault persists, replace the
HBMU heat management unit. See
chapter "Replacing the HBMU heat
management unit".
Reset the appliance.
Replace the HBMU heat manage-
ment unit. See chapter "Replacing
the HBMU heat management unit".
Reset the appliance.
Check IO electrode for earth fault.
If the fault persists, replace the
HBMU heat management unit. See
chapter "Replacing the HBMU heat
management unit".
Reset the appliance.
Replace the HBMU heat manage-
ment unit. See chapter "Replacing
the HBMU heat management unit".
Reset the appliance.
Fit flue gas temperature sensor
correctly. See "Repairs".
Carry out mains reset after fault
has been remedied.
Replace the HBMU heat manage-
ment unit. See chapter "Replacing
the HBMU heat management unit".
Reset the appliance.
57