On Wed, 11 Dec 2013 11:49:18 -0600, Irreverent Maximus wrote:

If the system was reset and things were started over again
I would wager that the unit would work again. This time,
do the test with the cover in place.

This morning, I pulled the plug, and then, one by one,
disconnected *every* wire I could, and cleaned the contact
surfaces, and reconnected them.

I also blew compressed air over the boards, and tapped on
each solenoid of the gas valve and relays in the fan-control
PCB.

This took about an hour. When I powered it back up, I heard
a click click click, and then a small whoosh, and then after
a while, a bigger whoosh, and finally the blower.

The house is toasty right now - but it has only been working
for a couple of hours. Thanks for all the help & advice!
http://farm8.staticflickr.com/7370/1...9b2434e2_o.gif

I'll report back, to let you know how it progresses along
over the next day or three ...