Bosch Condens 7000 FP Installation And Service Instructions Manual page 59

1)
Type Fault Sub Cause
code code
B 6A 577 No flame detected
within the safety
time.
V 6A 578 No flame detected
within the safety
time.
V 6C 576 Ionisation current
> 0.9 μA during
preventilation.
B 6L 514 Loss of flame
during the flame
stabilization
period.
B 6L 515 Loss of ionisation
signal when boiler
is running.
V 6L 561 5 power-up
sequences (power
supply
disconnection
during burner
start).
Condens 7000 FP – 6721846699 (2022/12)
Description Test procedure/Cause
Ionisation current Air in gas line.
< 1.1 μA during safety
Excessively high flue system
time.
backpressure due to unfavourable
layout (too many deflections; cross-
section inadequate or too long;
horizontal sections too long).
Inadequately sized gas line cross-
sections (min. cross-section of the
gas supply pipe)
The gas pressure regulator is not
appropriate for the required gas
volume.
Gas supply pressure too low.
Check whether the plug-in connector
for the compensation/ionisation line
is correctly installed.
Check the connecting lead between
the burner control unit and the
monitoring electrode for poor
contacts, breaks and damage.
Check the connecting lead between
the ignition transformer and ignition
electrode for poor contacts (on
electrode and transformer), breaks
and damage.
Check electrode gaps and ignition/
monitoring electrode for damage.
Ignition/monitoring electrode dirty.
Ignition transformer faulty (no
ignition spark or delayed ignition
spark, "hard start").
Burner control unit defective.
No flame signal was If the service code is still displayed,
detected during the check the temperature switch
safety time. (Chapter 15).
Flue gas and/or supply
air route blocked.
Interlock following 3rd
attempt.
No flame signal was Electrode dirty or faulty.
detected within the
preventilation phase.
No flame signal was -
detected within the
flame stabilization
period.
Ionisation signal is lost -
when the burner is in
operation.
The burner control unit Check the 230 V power supply to the
was switched off 5 control unit.
times during the burner
start.
Operating and fault displays
Action
▶ Venting the gas line.
▶ Install properly dimensioned and
configured flue system.
▶ Install adequately dimensioned
gas lines.
▶ Install a gas pressure governor
that is appropriate for the
required gas volume and, if
necessary, notify the gas
supplier.
▶ If pressure too low, inform gas
company.
▶ Establish good electrical contact.
Replace cables if necessary.
▶ Align burner rod or electrode.
Replace defective electrode.
▶ Clean or replace ignition/
monitoring electrode.
▶ Replace ignition transformer.
▶ Replace burner control unit.
▶ Replace the temperature switch
if required.
▶ Clean the electrode and, if
necessary, replace it.
If replacing the electrode does
not resolve the issue, the burner
control unit must be replaced.
▶ None, the burner control unit
tries to start again.
▶ None, the burner control unit
tries to start again.
▶ Reset the burner control unit at
the reset button.
▶ Rectify power supply problem.
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