In article dCvPe.27992$xp.23311@trnddc02, says...
Marc,

Well if you "found" the problem then don't go looking further. You can't
help but monitor the situation as the days go by. If the breaker doesn't
flip then you found the problem.
I would get another AC outlet from a different breaker string over to your
tank though. I think another poster mentioned this as well.

Good luck,

Djay


Hi again Djay!

Sadly, running new electrical connections isn't an option at the moment.
We're selling the house (it goes on the market Monday), so I'm
frantically trying to finish all the "make house look good" projects.
Opening a new electrical project is out of the question, and in a couple
months we'll be moving anyway.

The odd thing (to me, not being an electrical engineer) is that the
problem manifested so intermittently. Four times over a two-week period,
though admittedly the last two times were on successive days. And, it
would never do it repeatedly if I flipped on/off the timer switch. It
was as if it took time for the problem to "build up" overnight. This
lead me to suspect bad caps in the transformer box.

As days go by I'll see if the problem recurs. In 10 minutes the timer
should flip for today, and I'll see if I've got another day of success.

Marc