RonABC wrote:
I am about to add electric baseboard heat to a finished attic space in a
house that I own.

The wiring diagrams in a book that I have and on the Internet show to create
a 220/240-volt system using a 12/2 feed up to the heater(s), with 12/3 going
from the heater to the thermostat. I assume that means that at the panel
box there would be a double breaker to create the 220/240-volt, and that the
white wire would be coded at the panel and at the heater to be black. But,
that seems a little strange to me.

Is that how it is supposed to be done, or is it better or more correct to
run 12/3 as the feed and use the black and red wires as the hot wires?


white marked black is fine.

s