S8XB-SVX001-1A-EN
67
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