Trane S8B1A040M3PSCA/C - Troubleshooting; 4.0 Fault Code Flame Rollout

S8XB-SVX001-1C-EN
69
Disconnect electrical
power to furnace
Remove, clean, and
reassemble burners.
Push RED reset on
both rollout switches
Cycle power to
furnace and call for
heat
Ignion occurs
Do all burners
ignite within 5
seconds?
Check burner alignment
Correct as needed
Check operaon
NO
Is flue piping
restricted?
Correct as needed
Check operaon
YES
Are flames from
burners impinging on
sides of heat
exchanger?
NO
YES
When fan comes
on, do flames
stay consistent?
Replace heat
exchanger
Check operaon
NO
Replace Roll out
switch
Check operaon
YES
DEFINITION:
Limit switches are safety devices
that will open when an abnormal
high temperature has been
sensed.
REMOVE ALL JUMPER WIRING TO
SWITCHES!
Under no circumstances, shall
these switches be le jumpered
when not troubleshoong.
YES
Are all burner flames directed
into heat exchanger with a
ght paern? (inadequately
aired burners tend to roll
back)
NO
NO
Check combuson air
blower, venng, heat
exchanger for blockage
(i.e. soong)
YES
4.0 Fault Code
Flame Rollout
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