Viessmann Vitopend 100-W Installation And Service Instructions Manual page 37

Fault messages on the display
Displayed System characteris-
fault code tics
F3 Burner in a fault
state
F4 Burner in a fault
state
F5 Burner control unit
fault
F30 Burner blocked
F38 Burner blocked
F50 No DHW heating
F51 No DHW heating
(cont.)
Cause
Flame signal is al-
ready present at
burner start
No flame signal
The air pressure
switch is closed
during the burner
start or does not
close when the ig-
nition load has
been reached
Short circuit, boiler
water temperature
sensor
Lead break, boiler
water temperature
sensor
Short circuit, cylin-
der temperature
sensor (gas sys-
tem boiler)
Short circuit, outlet
temperature sen-
sor (gas combi
boiler)
Troubleshooting
Measures
Check ionisation elec-
trode and connecting ca-
ble.
Switch ON/OFF switch
8 OFF and ON again (or
reset, see F2).
Check the ionisation elec-
trode and connecting ca-
bles, check the gas pres-
sure, check the gas train,
check the ignition and ig-
nition module.
Switch ON/OFF switch
8 OFF and ON again (or
reset, see F2).
Check the flue gas/venti-
lation air system, hoses,
air pressure switch and
connecting cables.
Switch ON/OFF switch
8 OFF and ON again (or
reset, see F2).
Check the boiler water
temperature sensor (see
page 40).
Check the boiler water
temperature sensor (see
page 40).
Check the sensor (see
page 40).
Check the sensor (see
page 40).
37