Trane S8B1A040M3PSCA/C - Troubleshooting; 6.3 Fault Code

72
S8XB-SVX001-1C-EN
DEFINITION:
Igniter Relay Fault – The control board has sensed
that the igniter relay has stuck closed
igniter Fault – The control board has sensed that
the igniter circuit is open or shorted.
Verify igniter harness is
not damaged and
connectors are ght
Disconnect igniter
and check resistance
Is resistance
reading between 37
– 70 ohms?
(at ~75F)
NO
Replace igniter.
Check operaon
YES
6.3 Fault Code
Igniter is good
Does igniter
glow?
Make a call for
1 stage heang
Igniter is good
Replace IFC, igniter relay has failed
YES
YES
Is 120 VAC
measured between
IGN-H and IGN-N?
Replace IFC, igniter
relay has failed
NO
Disconnect electrical
power to the furnace
NO
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