Rob wrote:
This is my current thermostat and wiring:

http://www.uploaddress.com//files/855/current1.jpg
http://www.uploaddress.com//files/855/current2.jpg

Although the photo doesn't show it, the red wire from the thermostat
is wire-nutted to two black wires, the black wire from the thermostat
is connected to another single black wire.

Okay, so here is my new thermostat:

http://www.uploaddress.com//files/855/new.jpg

Can someone give me some advice on how to properly hook this up?

Looks like the new one is a LineVoltPro. You can find the specific
model here, then they have links to the installation instructions.

http://www.iaqsource.com/index.php?m...s&prod_cat=233

Likely your existing stat is only switching one phase, while the new
stat switches both phases.

You need to bring both conductors from the wall heater back to the stat
to wire it up the way they show.


Warning...the following makes sense electrically, but I'm not sure if it
is acceptable to code. I'd appreciate it if someone else could verify.

Unless the thermostat does something "intelligent" to monitor load, you
should be able to treat the new thermostat as a single pole switch, same
as your old one. This would switch only one side of your heater,
leaving the other hot all the time.

Take the single black wire connected to the black thermostat wire, and
hook it up to the inner black wire. Insulate the end of the outer black
wire--this will be live when the heat is on.

Split the two black wires hooked to the old red wire, connect the one
going to the heater with the outer red wire, and the one going to the
supply to the inner red wire.

Chris