Electronic Thermostat

Moved into a house where the previous owner replaced simple thermostat-type mechanical (mercury lamp) with an electronic unit. mechanical type of course just closes a contact to complete the circuit of the gas valve and get through 24V coil gas valve.
Clearly Unit 2 of wire transfers can not do that because the device needs to establish the power electronics.
The new thermostat is to provide the reliable, think to replace the old unit that I found and seems to be functional (checked with a multimeter).

You are right, tstat mail must be fed, some cheaper thermostats uses 2 AA batteries (junk in my opinion) or the other is actually powered from 24 volts to the transformer, verify that its wired correctly, is this just an oven or is it also a cooling unit with this system?

heat only:
you must have 3 son, a wire between Rh and Rh on the unit stat on a wire between C and C on the unit stats, and a wire between the unit of W and W stat.

the son of Rh and C the power of stat, W is the open contact on the stats that closes when a call for heat occurred.

An electronic tstat works the same way a plant bulb mercury tstat. A tstat is just a switch. The only difference is that a bulb of mercury tstat uses mercury to complete an electrical circuit. Through voltage safety limit of one side of the gas valve through the mercury tstat, slumping to energize the gas valve.

On an electronic current tstat still works mentioned above, the "switch" is made using a printed circuit board.

Tstats For most electronics are considered morefficient, but you must Chanf the tstat if you are not satisfied with the operation.