Buderus Logano plus GB402 Installation And Maintenance Instructions For Contractors page 52

11 Troubleshooting
1)
Type Display code Fault Code
B 8L 534
V 8P 580
V 8U 581
V 9Y 500
501
502
503
V CY 566
V CY 567
V CO 568
V CO 569
Table 23 Fault displays
1) V = locking; B = blocking
52
Reason Description:
No gas pressure There is no gas
or additional flue pressure although
gas pressure solenoid valve 1 should
limiter (pressure have opened. The
> 7.5 bar) has burner makes three
responded. successive attempts at
starting, then it waits
for one hour before
making three more
start attempts.
Solenoid valve 1 The valve test system
leaking has detected an
unacceptably high
leakage rate on
solenoid valve 1.
Solenoid valve 2 The valve test system
leaking has detected an
unacceptably high
leakage rate on
solenoid valve 2.
Internal SAFe Internal SAFe
relay faulty. electronics faulty.
Return The control unit
temperature receives unrealistic
values from the return
< -5 °C
sensor.
(interruption)
Return The control unit
temperature receives unrealistic
values from the return
> 130 °C (short
sensor.
circuit)
Water pressure Water pressure sensor
sensor fault interruption (voltage >
(cable break). 3.5 V).
Water pressure Water pressure sensor
sensor fault short circuit (voltage <
(short circuit). 0.5 V).
Test procedure/cause
Check that the gas isolator is
open.
Check whether there is gas
pressure.
Check whether the flue gas
pressure limiter has responded.
Check electrode.
Check ignition transformer.
Check gas filter for
contamination.
Check the gas valve for
contamination.
Gas filter fitted.
Check the gas valve for
contamination.
Gas filter fitted.
Press "Reset" and wait to see if
the fault has been removed.
Check cabling between SAFe and
return sensor.
Check electrical connection of the
SAFe cable.
Check the resistance values of the
temperature sensor against the
table.
Check voltage at the temperature
sensor terminals inside the SAFe
according to table.
Check cabling between SAFe and
return sensor.
Check electrical connection of the
SAFe cable.
Check the resistance values of the
temperature sensor against the
table.
Check voltage at the temperature
sensor terminals inside the SAFe
according to table.
Check lead to water pressure
sensor.
Check water pressure sensor.
Check lead to water pressure
sensor.
Check water pressure sensor.
Logano plus GB402 – 6 720 820 700 (2018/01)
Corrective measure
Replace the gas valve if
required.
Check the gas pressure.
Reset the flue gas pressure
limiter.
Check the flue gas path for
blockages.
Replace electrode if required.
Replace ignition transformer if
required.
Replace gas filter if required.
Replace the gas valve.
Replace the gas valve.
Replace the SAFe if the fault
persists after "Reset" has been
pressed.
Replace cable if required.
Remedy contact problem if
required.
Replace temperature sensor if
required.
Replace SAFe if resistance
values of the temperature
sensor are correct, but voltage
values are incorrect.
Replace cable if required.
Remedy contact problem if
required.
Replace temperature sensor if
required.
Replace SAFe if resistance
values of the temperature
sensor are correct, but voltage
values are incorrect.
Eliminate any interruption.
Replace water pressure
sensor.
Remedy any short circuit.
Replace water pressure
sensor.