According to dpb :
RickH wrote:
...
I've been looking for a 40F degree thermostat for 10 years now, let me
know if you find one. ...

I posted a link to one at Grainger yesterday in response to haller's
posting.

The other poster's suggestion of taking a good look at a
few makes of line-voltage thermostats for electric heat is
a good one.

Over thirty years ago, we found that some thermostats start
at around 50F with an offswitch, and others don't have an
offswitch, and start around 36F.

We wanted the 36F ones to keep a cottage just above freezing.
--
Chris Lewis,

Age and Treachery will Triumph over Youth and Skill
It's not just anyone who gets a Starship Cruiser class named after them.