Danny D'Amico wrote:
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).

Hi,
Leave that door open for now and tape down the switch. You may have a
intermittent ignitor. This is the one like BBQ lighter. When you hear
zapzap sound, you should be able to see spark. Remove the tape and close
the cover when problem is solved. Piezo ignitor is known to go bad when
old. I used to have that problem in my 5th wheel camping trailer fridge.
Only remedy is replacing whole module.