Maintenance; Putting The Control Unit Into The Service Position - Viessmann Vitodens 222-F Installation And Service Instructions For Contractors

Fault codes
(cont.)
Fault code dis- System characteristics
played
FC Burner in a fault state
Fd Burner in a fault state
FE Burner blocked or in a fault
state
FE Burner in a fault state and ad-
ditional fault B7 is displayed
FF Burner blocked or in a fault
state

Maintenance

!
Please note
Residual water will escape when the boiler or
one of the following components is fitted or
removed:
■ Water-filled pipework
Circulation pumps
■
Plate heat exchanger
■
Components fitted in the heating water or
■
DHW circuit
Water ingress can result in damage to other
components.
Protect the following components against
ingress of water:
■ Control unit (in particular in the service posi-
tion)
■ Electrical components
■ Plug-in connections
Cables and leads
■

Putting the control unit into the service position

If required for commissioning and servicing, the control
unit can be put into a different position.
Cause
Gas train faulty, modula-
tion valve control faulty or
flue gas path blocked
Burner control unit fault
EEPROM error, PCB
Boiler coding card missing Insert the boiler coding card.
Internal fault or reset but-
ton R disabled
Troubleshooting
Measures
Check connecting cables to the
gas train for damage.
Check gas train.
Check flue system for blockages or
constrictions.
Press reset button R.
Check ignition electrode, ionisation
electrode and connecting cables.
Check whether a strong interfer-
ence (EMC) field exists near the
appliance.
Press reset button R.
If the fault occurs sporadically, re-
place the coding card.
Replace control unit if fault is per-
manent.
Press reset button R. Replace con-
trol unit if fault persists.
Press reset button R.
Replace control unit if fault per-
sists.
Restart the appliance. Replace the
control unit if the appliance will not
restart.
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