Viessmann VG III - Page 29

29
Troubleshooting
Diagnostics (cont.)
Fault/behaviour
of the system
Flashing
code red
Cause Remedy
Burner does not
start (demand
3Ă× Burner motor
faulty
Replace burner motor
(
lamp illuminates)
Actuator faulty
(zero volt at
terminal 4)
Replace actuator
Burner does not
run and goes into
a fault state after
approx. 65 s
4Ă× Air pressure
switch
Check air pressure
switch settings and
replace switch if
necessary
pp
4Ă× Earth connection
at ionisation cable
or electrode
Remedy short-circuit
Burner motor
starts, but a fault
3Ă× Dirty air pressure
switch connection
Clean connection
,
shutdown occurs
during pre-purge
phase
3Ă×
Air pressure
switch incorrectly
set or faulty
Adjust or replace air
pressure switch (see
page 18)
3Ă× Air pressure too
low
Clean impeller (see
page 19)
Burner starts up,
but no flame is
2Ă× Ignition electrode
poorly adjusted
Adjust correctly (see
page 21)
formed
2Ă×
Ignition electrode
damp and
contaminated
Clean ignition electrode
2Ă× Insulation of
ignition electrode
cracked
Replace ignition
electrode
2Ă× Ignition
transformer faulty
Replace ignition
transformer
2Ă× Ignition cable
earthing
Replace ignition cable
5692Ă534ĂGB