Buderus Logano plus GB312 Installation And Maintenance Instructions Manual page 60

10
Troubleshooting
Display Fault
1)
Type code code
V 3C 537
V 3C 538
V 3C 540
V 4A 520
Tab. 28 Fault displays
1) V = locking; B = blocking
60
Cause Description
No speed. The SAFe receives
no speed
feedback,
although the fan
is supposed to be
running.
Fan speed too The detected
low. speed is lower
than the specified
speed.
Excessively The detected
high fan speed is higher
speed. than the specified
speed.
Intelligent high The flow
limit safety temperature has
cut-out in flow. reached a value of
100 °C.
Test procedure/cause
Check cabling between the
SAFe and the fan for
contact separation, breaks
and damage.
Check plug-in connection
at the SAFe and the fan.
Fan contaminated.
Fan faulty.
Check PWM signal/SAFe
cabling for contact
separation, breaks or
damage.
Check plug-in connections
for damage.
The boiler temperature
sensor monitors the
temperature increase in the
boiler. This results in a
timely burner shutdown.
Therefore, this fault
message can generally not
appear.
Unfavourable hydraulics in
two-boiler systems: boilers
influence each other, e.g.
via the return or flow.
Logano plus GB312 - Subject to technical modifications.
Action
Make the contacts
correctly. Replace cable
if required.
If power is available (no
fan start), replace fan.
Clean fan if required.
Replace fan.
Make the contacts
correctly. Replace cable
if required.
Replace fan.
Check hydraulics.