On Tue, 10 Dec 2013 18:19:44 -0600, Irreverent Maximus wrote:

Does the blower immediately turn on still?
If no: Switch thermostat to -heat- and set to highest temperature. Go
back to the furnace and listen. The blower should be running and
in a minute, or so, the burner should kick on. This unit might have
a delay for the blower, so wait 2 minutes before deciding that things
are not functioning. That is it for this part until you come back
with an answer.
If Yes: Either the heating or the cooling relay is sticking. Once again, get
back with an answer.

Wow. I tried this just now, in the dark, and, for a short while, everything was
working again!

The click click click I had heard was a snapping sound as the pilot was being
lighted. Soon, the pilot light lit!
http://farm3.staticflickr.com/2845/1...8bf71569_o.gif

Then, after about a minute (I didn't measure it), the entire burner was aflame!
http://farm8.staticflickr.com/7397/1...80c6d243_o.gif

And, within another while (again, I didn't think to measure), the blower ran!
http://farm8.staticflickr.com/7427/1...ceb36cd5_o.gif

I accidentally hit the door switch while I was trying to measure voltages,
so the whole thing shut down - and I couldn't reproduce the success - but -
I'll try again tomorrow when I have more light to work with (and it will
be warmer besides, as it's going to be at freezing tonight).