Came home from a long weekend and found the house cold. One flash, I shut down the furnace and restarted. Everything worked except the fan would not turn on also the furnace did not shut down and give me the same code. So I just turned the furnace off. The fan will work when I place the switch on fan. I am guessing it is the fan switch.

If the fan is controlled off a circuit board, the relay for the fan in the heating speed is probably shot. You can test by measuring voltage from the fan 'heat' terminal to neutral. After a few seconds of the burner firing (no longer that probably 30 seconds) you should get 120 volts AC from that terminal. If you do, the problem is not the board.