Furnace - Janitrol GMP100-3 (circa 2000)

I can turn on the air conditioner and the fan, but the furnace isn't working at all. There are no pilots lit. It's like it has no power, but when I remove the panel and check the wires, I can get the red LED light to come that indicates whether the front panel is on or not. Help!

By the way, I reset the breaker, switched the inside power switch and external switch on and off. Nothing. I have a Honeywell digital thermostat, but it all worked last winter.

It was as simple as checking the battery contacts at the thermostat. Works fine now.