Again from the manual. You have found the aux limit in the blower, the roll out near the burner still need to locate the priXXXXX XXXXXmit
Open Thermal Protection Device. If the primary (high)
limit, auxiliary limit, or rollout limit control opens, the
gas valve is de-energized. Both the induced draft blower
motor and air circulator blower are energized on low
heat speed. The diagnostic light code for this problem
is four short flashes followed by a longer pause.
If the primary or auxiliary limit is open, the probable
cause is either: low conditioned air flow due to dirty filter
or high resistance in duct work, faulty limit, faulty
blower, or blower speed set too low. The priXXXXX XXXXXmit
will automatically reset, while the auxiliary limit control
must be manually reset.
If the rollout limit control is open, the probable cause is
insufficient combustion air, restricted flue passage, or
restricted heat exchanger. The rollout limit control must
be manually reset.
6. Flame Sensed with No Call for Heat. If the co