Viessmann VG III - Page 30

30
Troubleshooting
Diagnostics (cont.)
Fault/behaviour
of the system
Flashing
code red
Cause Remedy
Burner starts up,
but no flame is
formed
2Ă× Insufficient
combustible gas
mixture available
Vent gas supply line to
the outside. Check with
a test burner, whether
sufficient combustible
gas is available.
2Ă× Gas solenoid
valves fail to open
Check electrical
connection, voltage
across gas train (230 V).
Replace gas train if
voltage is present at
valve.
Burner starts up
and ignition is
OK, but burner
enters a fault
2Ă× Start gas volume
poorly adjusted
Adjust start gas volume
or opening
characteristics (see page
14)
state after expiry
of safety time
2Ă×
Ionisation current
too low (<4 µA)
Check position of
ionisation electrode (see
page 21)
Burner starts up
and ignition is
OK, but burner
enters a fault
state after expiry
of safety time
2Ă× While gas train is
opened, voltage
briefly dips below
180ĂV
Check electrical
installation
Burner starts,
flame is
established, but
system is shut
down after a
short while (not a
fault shutdown)
Lack of gas Clean or replace gas
filter.
Check gas governor
settings.
Check gas flow
pressure.
5692Ă534ĂGB