Function Sequence And Possible Faults (Gas Condensing Module) - Viessmann Vitovalor PT2 E11T Installation And Service Instructions Manual

Checking the static pressure and supply pressure
Supply pressure (flow pressure)
Below 17.4 mbar (1.74 kPa)
17.4 to 25 mbar (1.74 to 2.5 kPa)
Above 25 mbar (2.5 kPa)

Function sequence and possible faults (gas condensing module)

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
Measures
Do not commission the appliance. Notify the gas supply utility.
Start up the appliance.
Connect the separate gas pressure governor upstream of the system and
set the pre-charge pressure to 20 mbar (2.0 kPa). Notify the gas supply
utility.
Display
No
No After approx. 51 s fault F.71
No Fault F.65, F.359, F.379
No
Fault F.65, F.357, F.379
No
Fault F.65, F.361, F.379
No
Shuts down below the set
boiler water temperature and
restarts immediately
Commissioning, inspection, maintenance
(cont.)
Measure
Increase set value and en-
sure heat is drawn off
Check the fan, fan connect-
ing cables, power to the fan
and fan control
Check ignition module (con-
trol voltage 230 V across
plugs "X18.1" and "X18.3" on
the burner control unit).
Check the gas supply.
Check the gas train (control
voltage 230 V
gas supply pressure.
Check setting for ionisation
electrode.
Purge the gas line.
Check the flue system for
tightness (flue gas recircula-
tion); check the gas flow
pressure.
∼
); check the
63