Buderus Logano plus GB312 Installation Manual page 77

Type Display
1)
code Fault code Cause
V 4U 524
V 4A 575
B 5L 542
Tab. 17 Fault messages
1) V = locking; B = inhibiting; BC = operating code
Logano plus GB312 - Technical specifications are subject to change without prior notice
Description
Flow temperature sen- Temperature at flow
sor short circuit. temperature sensor
> 266 °F
(> 130 °C)
ISTB response. The boiler flow tem-
perature has
reached the maxi-
mum limit.
Incomplete communi- The MC10 regis-
cation with SAFe. ters this fault if not
all required data is
supplied by the
SAFe.
Troubleshooting
Testing
sequence/Cause Action
Check sensor lead. Replace if dam-
aged.
Check connector.
If dirty, clean or
Check sensor read-
replace as neces-
ings against sensor
sary.
characteristic.
If connector is
Check temperature
loose, reconnect
sensor voltage levels
properly.
against table (SAFe
documentation). Replace tempera-
ture sensor if there
are discrepancies.
Replace SAFe if
there are discrep-
ancies.
High temperature Check gas valve.
safety cut-out has
tripped.
Check wiring con- If connections OK,
nections between replace SAFe
SAFe and MC10.
10
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