Our furnace has just started acting up... When it gets a "call for heat," the yellow/orange glow from the igniter comes on, the fan blows, and I THINK I can hear the gas come on. But no ignition (the main gas burner chambers do not light), and a few seconds later, the igniter goes off (after being on for maybe 10 sec total). The fan continues to run, blowing cold air gently through the ducting. The red status light just continually flashes rapidly, indicating "call for heat" according to the sticker on the inside of the panel. I can't tell for certain if the gas ever flows in to the burners. Twice last night I turned the blue gas knob from ON to OFF and back. The next call for heat resulted in ignition and an operating furnace... until the thermostat kicked the furnace off and it wouldn't relight.
Tonight even the cycling-the-switch trick won't make it work.

Ideas for troubleshooting?

Pete in CO

Pete,
Sorry for the delay in replying. Somehow I just plain missed your question.

Do you have a voltmeter & know how to use it? If so, there is some basic troubleshooting we can do.