i have been experiancing problems with my furnace blowing out cold air, the first time i checked the code light it was working normal, the second time it was flashing continuosly fast and it meant call for heat, the third time i checked it said to replace the IFC!! i have no idea what the ifc is, and i was just wondering if you could give me some tips on how to fix this problem!!

What brand is your furnace?? Do the burners come on when you turn the thermostat up to the point that it calls for heat??

Many modern furnaces, whatever the brand, follow the sequence of the thermostat closes switching power from the red wire to the white wire, a small blower (Inducer) starts providing combustion air, the ignitor comes on, the gas comes on and lights, and after a timed delay, the blower comes on. There are sensors that will stop the process if anything fails.

If the blower runs continually without any heat, likely the control board is getting a signal from a temperature sensor that the heat exchanger area is over heating. Does the furnace have a diagram on it that would help you identify the IFC? It should be in the heat exchanger area. The type and location will vary with the brand.