Viessmann B2TF - Page 89

89
Displayed fault
code
System characteristics Cause Measures
F.386 Burner in a fault state BCU burner control unit
faulty
Replace BCU burner control unit:
See page 100.
Reset the appliance.
F.387 Burner in a fault state Earth fault, ionisation cur-
rent. BCU burner control
unit faulty.
Check ionisation electrode and
connecting cable. If fault persists,
replace BCU burner control unit:
See page 100.
Reset the appliance.
F.388 Burner in a fault state BCU burner control unit
faulty
Replace BCU burner control unit:
See page 100.
Reset the appliance.
F.395 Burner in a fault state IO electrode earth fault,
BCU burner control unit
faulty
Check ignition electrode for earth
fault. If fault persists, replace BCU
burner control unit: See page 100.
Reset the appliance.
F.396 Burner in a fault state BCU burner control unit
faulty
Replace BCU burner control unit:
See page 100.
Reset the appliance.
F.399 Burner in a fault state IO electrode earth fault,
BCU burner control unit
faulty
Check IO electrode for earth fault.
If fault persists, replace BCU burn-
er control unit: See page 100.
Reset the appliance.
F.400 Burner in a fault state BCU burner control unit
faulty
Replace BCU burner control unit:
See page 100.
Reset the appliance.
F.401 Burner in a fault state IO electrode earth fault,
BCU burner control unit
faulty
Check IO electrode for earth fault.
If fault persists, replace BCU burn-
er control unit: See page 100.
Reset the appliance.
F.402 Burner in a fault state BCU burner control unit
faulty
Replace BCU burner control unit:
See page 100.
Reset the appliance.
F.403 Burner in a fault state Ionisation electrode earth
fault, BCU burner control
unit faulty
Check IO electrode for earth fault.
If fault persists, replace BCU burn-
er control unit: See page 100.
Reset the appliance.
F.404 Burner in a fault state BCU burner control unit
faulty
Replace BCU burner control unit:
See page 100.
Reset the appliance.
F.405 Burner in a fault state Ionisation electrode earth
fault, BCU burner control
unit faulty
Check IO electrode for earth fault.
If fault persists, replace BCU burn-
er control unit: See page 100.
Reset the appliance.
F.406, F.408,
F.410
Burner in a fault state BCU burner control unit
faulty
Replace BCU burner control unit:
See page 100.
Reset the appliance.
F.416 Burner locked out Flue gas temperature sen-
sor incorrectly positioned
Fit flue gas temperature sensor
correctly. See "Repairs".
Carry out mains reset after fault
has been remedied.
F.417, F.418 Burner in a fault state BCU burner control unit
faulty
Replace BCU burner control unit:
See page 100.
Reset the appliance.
Troubleshooting
Fault messages (cont.)
6151778
Service