Function Sequence And Possible Faults - Viessmann Vitodens 242-F Installation And Service Instructions Manual

Commissioning, inspection, maintenance

Function sequence and possible faults

Control unit issues a heat
demand
Yes
Fan starts
Yes
Ignition
Yes
Gas train opens
Yes
Ionisation current builds
Symbol
A
Yes
Burner in operation
Yes
Automatic calibration of
the combustion controller
For further details regarding faults, see page 93.
46
Display
No
No
After approx. 51 s fault F9
No
Fault EE
No Fault EE
No Fault EE
No Shuts down below the set
boiler water temperature and
restarts immediately
Fault E3
No
Fault Eb
Measure
Increase set value and en-
sure heat is drawn off
Check the fan, fan connect-
ing cables, power at the fan
and fan control
Check ignition module (con-
trol voltage 230 V across
plugs "X2.1" and "X2.2").
Check the gas supply.
Check the gas train (control
∼
voltage 230 V ); check the
gas supply pressure.
Check setting of ionisation
electrode.
Purge the gas line.
Check the flue system for
tightness (flue gas recircula-
tion); check the gas flow
pressure.
Ensure adequate heat trans-
fer. Press reset button R.
Check gap between ionisa-
tion electrode and burner
gauze assembly.
Check allocation of gas type
(coding address 82, gas train
setting).
Check flue system; remedy
flue gas recirculation if re-
quired.
Press reset button R.