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

Troubleshooting
Fault codes
(cont.)
Fault code dis- System characteristics
played
FE Burner in a fault state and ad-
ditional fault B7 is displayed.
FE Burner blocked or in a fault
state
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
■ Heat exchanger
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 components (especially in the
service position)
■ 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.
94
Cause
Boiler coding card miss-
ing.
Boiler coding card or main
PCB faulty, or incorrect
boiler coding card
Internal fault or reset but-
ton R blocked.
Measures
Insert the boiler coding card.
Press reset button R.
Replace control unit if fault per-
sists.
Press reset button R. If the fault
persists, check the boiler coding
card and replace boiler coding card
or control unit if necessary.
Restart the appliance. Replace the
control unit if the appliance will not
restart.