Up until yesterday my furnace was working fine now it does not come on at all. I have turned off the power to it and the breaker and still nothing. I also have tried turning on the air and that does not come on either. I don't know the model number but I have been using it for about 4 years now.

Check for a fuse on the control board. Check for 24 volts between the R and c terminal on the board.