Viessmann VITODENS 242-F Installation And Service Instructions Manual page 132

Troubleshooting
Fault codes
(cont.)
Displayed System characteris-
fault code tics
E1 Burner in a fault
state
E3 Burner in a fault
state
E4 Burner blocked
E5 Burner blocked
E6 Burner blocked
E7 Burner in a fault
state
132
Cause
Ionisation current
too high during cal-
ibration
Heat transfer too
low during calibra-
tion.
Temperature limit-
er has shut down.
Fault, 24 V supply
voltage
Fault, flame ampli-
fier
System pressure
too low
Ionisation current
too low during cali-
bration
Measures
Check gap between ioni-
sation electrode and burn-
er gauze assembly (see
page 61).
In open flue operation,
prevent high incidence of
dust in the combustion
air.
Press reset button R.
Ensure adequate heat
transfer.
Press reset button R.
Replace control unit.
Replace control unit.
Top up with water.
Check ionisation elec-
trode:
■ Distance to burner
gauze assembly (see
page 61)
■ Contamination of elec-
trode
■ Connecting lead and
plug-in connections
Check flue system; reme-
dy flue gas recirculation if
required.
Press reset button R.