Bosch Condens 7000 FP Installation And Service Instructions Manual page 61

1)
Type Fault Sub Cause
code code
B 8L 579 No gas supply
pressure.
V 8P 580 Solenoid valve 1
leaking.
V 8U 581 Solenoid valve 2
leaking.
B 8U 584 No diverter
module feedback
V 9Y 500 Fault in the
internal relay of
501
the burner control
502
unit.
503
V A01 800 Outside
temperature
sensor is faulty
V A01 808 Control device
receiving invalid
values from DHW
temperature
sensor
Condens 7000 FP – 6721846699 (2022/12)
Description Test procedure/Cause
Although the solenoid Check that the gas isolator is open.
valve 1 must have
Measure the gas supply pressure.
opened, there is no gas
if applicable, Replace air/gas ratio
supply pressure. The
control valve.
burner makes three
successive attempts at
starting, then waits for
one hour before making
three more start
attempts.
The valve test system Check the air/gas ratio control valve
has detected an for contamination.
unacceptably high
Gas filter fitted.
leakage rate on solenoid
valve 1.
The valve test system Before replacing the air/gas ratio
has detected an control valve, check the function of
unacceptably high the siphon and condensate drain
leakage rate on solenoid (condensate back-up).
valve 2.
Check the air/gas ratio control valve
for contamination.
Gas filter fitted.
Diverter module does No feedback from external
not receive feedback components.
within the specified
Power cable damaged or faulty.
time.
Faulty external component.
Internal electronic fault Press the "Reset" button and wait to
in the burner control see if the fault is eliminated.
unit.
Temperature sensor Check configuration.
incorrectly connected
Check the sensor port and sensor
or installed.
lead.
Breakage or short
Check installation of sensors.
circuit in the sensor
Check resistance values of
lead.
temperature sensor against table.
Temperature sensor is
defective.
Temperature sensor Check the sensor port and sensor
incorrectly connected lead.
or installed.
Check the sensor mounting on the
Breakage or short cylinder.
circuit in the sensor
Check resistance values of
lead.
temperature sensor against table.
Temperature sensor is
defective
Operating and fault displays
Action
▶ If necessary, replace the air/gas
ratio control valve.
▶ Check whether there is any gas
supply pressure.
▶ Replace air/gas ratio control
valve.
▶ Replace air/gas ratio control
valve.
▶ Check flue gas damper or other
connected component.
▶ Check diverter module.
▶ Check the plug-in connection.
▶ Replace power cable if
necessary.
▶ Replace external component if
necessary.
▶ If the fault persists after "Reset",
the burner control unit must be
replaced.
▶ Change configuration.
▶ If necessary, eliminate the
contact problem.
▶ Replace the temperature sensor
if necessary.
▶ If the connecting lead, contacts
and resistance values are all OK,
replace the control unit.
▶ If necessary, eliminate the
contact problem.
▶ Replace the temperature sensor
if necessary.
▶ If the connecting lead, contacts
and resistance values are all OK,
replace the control unit.
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