10
Troubleshooting
Logano plus GB312 – 6 720 806 273 (2013/01)
61
10.3
Troubleshooting the safety sequence/pressure switch
Faults 8Y/590 (interlocking)
Cause:
pressure switch in safety sequence has tripped.
Description:
cut-out in pressure switch safety sequence during burner
operation.
Fig. 69 Troubleshooting procedure 8Y/590
Is the low pressure switch
setting (natural gas: 3 inches
w.c., propane: 7 inches w.c.)
correct?
yes
no
Is continuity
OK on SAFe
pressure
switch?
yes
no
Is the main gas cock turned
on and is gas pressure
present?
Turn on the main
gas cock!
Switch boiler OFF
and ON again on
controller!
no
Correct setting!
Switch boiler OFF
and ON again on
controller!
yes
Turn on manual gas
isolating cock upstream
of Venturi!
Check gas valve
connector is making
proper contact!
Switch boiler OFF
and ON again on
controller!
Check high pressure
switch (available separately),
air supply monitor and flue
gas monitor for clear passage
with the burner off.
Is there clear
passage on all
pressure switches?
Replace the
pressure switch
that has tripped!
Switch boiler OFF
and ON again on
controller!
Switch boiler OFF
and ON again on
controller!
no
yes
Does Fault
8L / 579 recur?
Replace low
pressure switch
(available separately)