Yet another thermostat wiring question. Newbie needs help.

[shipspeed]

Hi All,

I've been searching through prior threads without luck. I'm not sure how to properly connect my new thermostat and could use your expert advice. The situation:

SYSTEM
Simple electric wall heater; no AC or anything fancy. Three wires from wall (2 black, 1 white).

OLD THERMOSTAT SETUP
Black#1 (from wall) to Red (on old thermostat)
Black#2 (from wall) to Black (on old thermostat)
White (from wall) to White (on old thermostat)

NEW THERMOSTAT OPTIONS (instruction manual notes)
W (heating; not for heat pumps)
RH (24 volt)
RC (24 volt cool)
G (fan)
Y/Y1 (AC compressor)
O/B (reversing valve for single stage heat pumps)

QUESTION
On the new thermostat, where should the 2 black wires and 1 white wire from the wall connect? I'm guessing white to W, and black#1 to the RH. But what about black#2? Should that go to RC? Note: the RH and RC have a jumper wire connecting them by default.

Thanks for any help!

[williswires]

Please give us:
the make, model, or electrical data from the heater nameplate

the make and model of your old thermostat (or any nameplate data from it)

the make and model of your new thermostat

Your wall heater is probably line voltage (120V/240V), but your new thermostat seems to be a 24V tstat. If your old tstat was line voltage, it directly controlled the heater and would have to be replaced with another line voltage tstat.