> The furnace does, in fact, reset itself after an hour lockout, and I get heat until
> the next time it loses flame 5 times in a cycle, when it locks me out again.
Probably the inducer motor loosing vacuum to the pressure switch, maybe bad vacuum hose or loose, or could even be a bad pressure switch. If it was the flame sensor, the burner would shut down within 5 seconds of start, if it was a bad limit the fan only would run, no burner. Flame sensors hardly ever go bad, you can usually clean them with steel wool, also check your grounds, bad ground will cause the flame sensor to not operate correctly.