Furnace just stopped

[Selfdoer]

First the furnace blower would not shut off even if I turn the temp all the way down. I would have to turn off the thermastat. I pop the circuit breaker off and then on and the blower comes back on. In frustration I hit the furnace, the blower turned off, and the pilot stayed lit. Now the furnace will not come on at all. The A/C still works. At the end of the summer ths same problem occured with the A/C, the fan would not turn off, but when winter hit the heating worked fine to a few days ago. If I turn on the A/C and lower the temp, it goes on fine. I have a Arcoaire Snyder General, RPJ Heat Exchanger GUG070A008N.

Any ideas on what to try?
Thanks,