Trane S8B1A040M3PSC Installation, Operation And Maintenance Manual page 75

Defini on:
The IFC has detected that internal gas valve
relays have failed.
Defini on:
The onboard 5 amp fuse is open or missing.
Correct low voltage
NO
wiring
S8XB-SVX001-1B-EN
Replace fuse
Start unit and
measure amp draw
on transformer
24VAC red wire
Is amp draw less
YES
than 5 amps?
11 Fault Code
Verify all wiring
Replace IFC
12 Fault Code
Apply power to the
unit
Is 24 VAC
measured across
the fuse terminals?
Turn on each accessory (if
installed) and measure amp
draw. If amp draw exceeds
fuse ra ng, correct wiring
associated with that accessory
T T r r o o u u b b l l e e s s h h o o o o t t i i n n g g
Is fuse fully
NO seated into NO
connector?
YES
Replace IFC
Properly seat the
fuse
75