albee wrote:
....

Okay, replaced the upper thermostat. Still no reading between L1 and
L3; should there be? Still 120 from each pole to ground.
No reading between the upper element contact screws, so no power is
getting there. Another bad thermostat? I'm stumped (but that doesn't
take much).

That symptom indicates the two legs (red and black) are from the same
phase instead of from the two alternate phases. That's a miswiring
somewhere that connected them both to the same side of the 240V breaker.

I've not followed this thread; just amazed this AM it was still alive
(and seemingly well) so glanced at your response here--did you
disconnect something looking to trace the power earlier? It would seem
perhaps if so that would be where it got crossed up when put back altho
just what would be where w/o two leads on one terminal is puzzling.
Unless there were pigtail connections, would be possible to have
inadvertently connected the two together. If it's been wired this way
all along it never would have had an upper element working.

Trace back from where the two power leads have the 120V and eventually
you'll find they're connected to the same side of the 240V supply.
Wherever that is, split them back apart and get one to each side.
You'll then still see 120V to ground but 240V relative to each other.

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