Two Wire Heater, Nest E, Rh to R?

[apotheosis415]

My old furance has no C wire, so I want to use the nest e since it has a battery option.

I have a W and an RH hook up on my old thermostat. Those labels are the thermostat readouts, not wire lables.

Can I just hook the RH wire to the R on the nest E?

I see the new nest, which needs a C wire, has a R and Rh. So I am tad confused...

Thanks all.

[CoolingWizard]

Apotheosis415,

Both the Nest-E and the Nest Learning Thermostat 3rd Generation can work without a COMMON wire.  Your current thermostat cable in the wall might have an additional unused conductor wire that can be utilized for the COMMON. Your furnace has a step down transformer in it and a COMMON wire can be established if, as I said, you have an unused conductor.

[EdwardT]

Hi folks,

@CoolingWizard, thanks for the help!

@apotheosis415, how's it going with your Nest Thermostat? Still need our help?

Thanks,

Edward

[EdwardT]

Hi apotheosis415,

It's me again. I wanted to check back in to see if you have other questions and concerns. Feel free to let me know if you do. 

Thanks,

Edward

[EdwardT]

Hi apotheosis415,

I'm just checking in to make sure that you've seen our response. Please let us know if you have any other questions or concerns as I will be locking this in 24 hours.

Thanks,

Edward