Viessmann C3TB, Installation And Service Instructions For Contractors

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120
Fault code dis-
played System characteristics Cause Measures
E7 Burner in a fault state Ionisation current too low
during calibration Check ionisation electrode:
■
Distance to burner gauze assem-
bly (see page 78)
■
Electrode soiled
■
Connecting cable and plug-in
connections
Check flue system; remove flue
gas recirculation if required.
Press reset
R .
E8 Burner in a fault state Ionisation current lies out-
side the permissible range Check gas supply (gas pressure
and gas flow switch), gas train and
connecting cable.
Check ionisation electrode:
■
Distance to burner gauze assem-
bly (see page 78)
■
Electrode soiled
Press reset R .
EA Burner in a fault state Ionisation current outside
permissible range during
calibration (excessive de-
viation from previous lev-
el) Check flue system; remove flue
gas recirculation if required.
In open flue operation, prevent
high levels of dust in the combus-
tion air.
Press reset
R .
Following several unsuccessful re-
set attempts, replace the coding
card and press reset
R .
Eb Burner in a fault state Repeated flame loss dur-
ing calibration Check gap between ionisation
electrode and burner gauze as-
sembly (see page 78).
Check flue system; remove flue
gas recirculation if required.
Press reset
R .
EC Burner in a fault state Parameter error during
calibration Press reset R or
replace coding card and press re-
set
R .
Ed Burner in a fault state Internal fault Replace control unit.
EE Burner in a fault state Flame signal at burner
start not present or insuffi-
cient. Check gas supply (gas pressure
and gas flow switch).
Check gas train.
Check ionisation electrode and
connecting cable.
Check ignition:
■
Connecting leads to ignition
module and ignition electrode
■
Ignition electrode gap and soiling
(see page 78).
Check condensate drain.
Press reset
R .
Troubleshooting
Fault codes for gas condensing module
(cont.)
5775 636 GB
Diagnosis