Its getting cold and this thing won't fire up. Fans come on but no flame-age! The little red led light blinks 3 times power switch (label on door says) is this a easy fix or should I call for help?

What does the code on the door read for 3 flashes? Does the ignitor ever glow?

Did my answer go through? On my door it just says that 3 blinks
Pressure switch failure to close (check) venter, pressure switch vent blockage there's no sort of lighting of anything but the blinking red light.no # codes that I can find. I have not received any answers as of yet. Please help