Viessmann Vitodens 222-F B2TA Installation And Service Instructions Manual page 131

Fault codes
(cont.)
Dis- Const.
played
fault
code
E7 X
E8 X
Weath.- System char-
comp. acteristics
X Burner in a fault
state
X Burner in a fault
state
Troubleshooting
Cause Measures
Ionisation Check ionisation
current too electrode:
low during ■ Distance to burn-
calibration er gauze assem-
bly (see page 52)
■ Contamination of
electrode
■ Connecting lead
and plug-in con-
nections
Check flue system;
remedy flue gas re-
circulation if re-
quired.
Press reset button
R
The ionisa- Check gas supply
tion current (gas pressure and
lies outside gas flow switch),
the permissi- gas train and con-
ble range necting lead.
Check allocation of
gas type (see
page 44).
Check ionisation
electrode:
■ Distance to burn-
er gauze assem-
bly (see page 52)
■ Contamination of
electrode
Press reset button
R
131