My heat was working 3 days ago. Now I am getting a blinking heat light on the computer panel and the fan is running continually. It is blowing air not any heat. The thermostat says the heat is on but the compressor is not kicking on outside. I am tried shutting down the power at the thermostat and at the breaker.

Any thoughts on what it might be??

What kind of furnace, how old? What's the efficiency? Is it a heat pump? How many flashes?