Viessmann VITODENS 200-W Installation And Service Instructions Manual page 66

Troubleshooting
Fault codes
(cont.)
Fault code dis- System characteristics
played
E1 Burner in a fault state
E2 Burner in a fault state
E3 Burner in a fault state
E4 Burner blocked
E5 Burner blocked or in a fault
state
E7 Burner in a fault state
66
Cause
Ionisation current too high
during calibration
No calibration as flow rate
too low
Heat transfer too low dur-
ing calibration
Temperature limiter has
shut down.
24 V power supply fault
Flame amplifier fault
Ionisation current too low
during calibration
Measures
Check gap between ionisation
electrode and burner gauze as-
sembly (see page 35).
Check whether there is a lot of
dust in the ventilation air (e.g. from
construction work).
Note
Deposits on the electrodes indicate
foreign bodies in the ventilation air.
Check the installation room and
flue system for causes of the de-
posits. For example: Laundry de-
tergents, cleaning agents, toilet-
ries, deposits in the ventilation air
supply (chimney).
If burner gauze assembly and ioni-
sation electrode have been re-
placed, also clean fan unit, gas/air
channel and Venturi extension.
Ensure adequate heat transfer.
Press reset button R.
Ensure adequate heat transfer.
Check circulation pump for faults,
scale or blockages.
Press reset button R.
Replace control unit.
Press reset button R.
Replace control unit if fault is per-
manent.
Check the ionisation electrode and
connecting lead (see page 35).
Check plug-in connections for
loose contacts.
Check flue system; remove flue
gas recirculation if required.
Press reset button R.
Note
Deposits on the electrodes indicate
foreign bodies in the combustion
air. Check the installation room and
flue system for causes of the de-
posits. For example: Laundry de-
tergents, cleaning agents, toilet-
ries, deposits in the ventilation air
supply (chimney).
If burner gauze assembly and ioni-
sation electrode have been re-
placed, also clean fan unit, gas/air
channel and Venturi extension.