On Tue, 4 Jun 2013 00:03:56 +0000 (UTC), Tegger
wrote:

This thing keeps my basement from being dank and dungeon-like.

Occasionally this dehumidifier would refuse to shut off and would turn the
coils into a solid block of ice. I would unplug it, let it thaw, plug it
back in, and it would work fine again for weeks or months more.

But now it refuses to turn off at all. Plug it in and it runs forever and
goes all Ice-Agey on me every time.

What's wrong?

This isn't a direct answer to your question but can you just plug it
into a timer and have the timer shut it down?