On Wed, 31 Dec 2014 23:37:23 +0000 (UTC), "Danny D."
wrote:

trader_4 wrote, on Wed, 31 Dec 2014 05:29:47 -0800:

I'm left wondering what the actualy failure was.

I am clueless.

Maybe cracked ceramic that only opened up under red
hot heating of the metal rod?

Even then, what's the failure mode?
It would just be easier for the electrons to get to
the chassis (which is what they're trying to do
through the flame).

I really do not understand the failure mode, especially
as this thing is clean as can be.

I wish I understood HOW it failed.

My guess is the metal expands and opens a crack in the ceramic (not
visible). I've read about this on a gas grill and stove igniters.
Don't recall the details - sorry. I was hinting about it earlier in
the thread. Would that be a short to ground?