Bryant Plus 80 gas furnace won't start up

[Eastfork]

Tried to turn on the heater this morning and nothing happened so I went up in the attic, checked furnace and discovered the flashing LED "problem" code which said: "Gas heating lockout" either a: "defective control (valve relay)" or "mis-wired gas valve." I suspect it's the "control" since the furnace has been operational for several years...Any suggestions on how to proceed? I'm pretty handy and if possible, would like to replace the part, but maybe someone has an idea WHERE TO START in this trouble-shooting process??? Thanks so much!

[hvacwiz]

Could be just your hot surface ignitor is out.