SLOW GREEN FLASH: Normal operation.

SLOW AMBER FLASH: Normal operation with call for heat.

RAPID RED FLASH: Twinning error, incorrect 24V phasing. Check
twinning wiring.

RAPID AMBER FLASH: Flame sense current is below 1.5 microamps.
Check and clean flame sensor. Check for proper gas flow.

4 AMBER FLASHES: The control board is recieving a “Y” signal from
the thermostat without a “G” signal, indicating improper thermostat wiring.

1 RED FLASH: This indicates that flame was sensed when there was
not a call for heat. With this fault code the control will turn on both the
inducer motor and supply air blower. A gas valve that leaks through or
is slow closing would typically cause this fault.

2 RED FLASHES: This indicates that the normally open pressure
switch contacts are stuck in the closed position. The control confirms
these contacts are open at the beginning of each heat cycle. This would
indicate a faulty pressure switch or miswiring.

3 RED FLASHES: This indicates the normally open pressure switch
contact did not close after the inducer was energized. This could be
caused by a number of problems: faulty inducer, blocked vent pipe, broken
pressure switch hose or faulty pressure switch.

4 RED FLASHES: This indicates that a primary or auxiliary limit switch
has opened its normally closed contacts. With this fault code the control
will operate the supply air blower and inducer. This condition may be
caused by: dirty filter, improperly sized duct system, incorrect blower
speed setting, incorrect firing rate or faulty blower motor.

5 RED FLASHES: This fault is indicated if the normally closed contacts
in the rollout switch opens. The rollout control is manually reset. If it has
opened, check for proper combustion air, proper inducer operation, and
primary heat exchanger failure or burner problem. Be sure to reset the
switch after correcting the failure condition.

6 RED FLASHES: This indicates that after the unit was operating, the
pressure switch opened 4 times during the call for heat. If the main
blower is in a “Delay on” mode it will complete it, and any subsequent
delay off period. The furnace will lock out for one hour and then restart.

7 RED FLASHES: This fault code indicates that the flame could not be
established. This no-light condition occurred 3 times (2 retries) during
the call for heat before locking out. Low gas pressure, faulty gas valve,
faulty hot surface ignitor or burner problem may cause this. The furnace
will lock out for one hour and then restart.

8 RED FLASHES: This fault is indicated if the flame is lost 5 times (4
recycles) during the heating cycle. This could be caused by low gas
pressure or faulty gas valve. The furnace will lock out for one hour and
then restart.

9 RED FLASHES: Indicates reversed line voltage polarity or grounding
problem. Both heating and cooling operations will be affected. Check
polarity at furnace and branch. Check furnace grounding. Check that
flame probe is not shorted to chassis.

10 RED FLASHES: Gas valve energized with no call for heat. Check
gas valve and gas valve wiring.

11 RED FLASHES: This indicates that a primary or auxiliary limit switch
has opened its normally-closed contacts and has remained open for
more than five minutes. This condition is usually caused by a failed
blower motor or blower wheel.

12 RED FLASHES: This code indicates an open igniter circuit, which
could be caused by a disconnected or loose wire or by a cracked or broken
igniter.

STEADY ON RED: Control failure. Replace control board.

60-MINUTE AUTOMATIC RESET FROM LOCKOUT: This control
includes a “watchdog” type circuit that will reset from a lockout condition
after 60 minutes. Operational faults 6,7,8 will be reset. This provides
protection to an unoccupied structure if a temporary condition exists
causing a furnace malfunction. An example would be a low incoming
gas supply pressure preventing unit operation. When the gas pressure
is restored, at some point the “watchdog” would restart the unit and provide
heat for the house.

NOTE: If a flame is detected the control flashes the LED for 1/8 of a
second and then enters a flame stabilization period.

Your going to have to look for a switch that looks like this. The only way you can reset these switches are if they have a small red button on top. The #4 error also makes a reference to a high limit. If that high limit is open and will not reset by itself you'll have to replace. it.