Buderus Logano plus GB402 Installation And Maintenance Instructions Manual page 48

10 Troubleshooting
Display
1)
Type code Fault code
B 6A 577
V 6L 561
B 7A 550
B 7A 551
B 7P 549
Tab. 22 Fault displays
1) V = locking; B = blocking
48
Cause Description
No flame within Ionisation current
the safety time. within the safety time
< 1.1 μA.
"Power up" The burner control unit
5 times (power was switched off 5
interruption times during the burner
during burner start.
start).
Undervoltage. The mains voltage is
too low.
Voltage There has been a brief
interruption. power failure.
The safety chain The continuity of the
has opened. external components
tied into the MC10
safety chain has been
interrupted.
Test procedure/cause
Gas supply pressure too low.
The gas governor is not adjusted
to the required gas volume.
Inadequately sized gas line cross-
sections (min. cross-section of
the gas supply pipe).
Air in the gas line.
Excessively high flue system
backpressure through
unfavourable layout (too many
diversions; cross-section
inadequate or too long; horizontal
sections too long).
Ignition/ionisation electrode
contaminated.
Check cabling between the SAFe
and the ionisation electrode for
contact separation, breaks and
damage.
Check electrode gaps and
ignition/ionisation electrode for
damage.
Check cabling between the
ignition transformer and ignition
electrode for contact separation
(on electrode and transformer),
breaks and damage.
SAFe burner control unit faulty.
Ignition transformer faulty (no or
delayed ignition spark, "hard
start").
Check the 230 V power supply to
the control unit.
The power supply must not fall
below 195 V.
Check the power cable for
possible loose contacts.
Check the wiring and correct
contacts of the mains plug at the
MC10 or SAFe.
Check the continuity of the
components.
Logano plus GB402 – 6 720 804 428 (2012/09)
Correction
Notify gas supplier if the supply
pressure is too low.
Install gas governor that is
adjusted to the required gas
volume or, if necessary, notify
gas supplier.
Install adequately sized gas
lines.
Purge the gas line.
Size and route the flue system
correctly.
Clean or replace ignition/
ionisation electrode.
Make the contacts correctly.
Replace cable if required.
Align burner rod or electrode.
Replace faulty electrode.
Make the contacts correctly.
Replace cable if required.
Replace the SAFe.
Replace the ignition
transformer.
Reset burner control unit.
Remedy problem with the
power supply.
Ensure the correct power
supply.
Remedy any contact problems.
If required, replace faulty
components.