How do we clear an IGNITION LOCKOUT FAULT?

Turn all power off. Wait a minute and re energize.

Turn all power off. Wait a minute and re energize.

The blower fan comes on immediately when I plug the unit, but the ignition doesn't start.
How can I reset the unit?

The blower fan comes on immediately

Sounds like the high limit is tripped. If it is and has a red button in the middle of the disc reset by pushing the red disk. You migh also have a different problem if your unit has a roll out device in the burner area. Those cannot be reset but replaced.

NOTE make sure your thermostat is not set to fan on.