Gen 3 Nest doesn't read power wire on a 2 wire system

[Wisky]

I have new Gen 3 Learning Nest.  My furnace is a 2 wire system - W and Rh.  I installed it and it worked for 1 day.  Then it did not read the Rh wire.  Put the old thermostat back on, it worked fine. I stripped both wires for a better contact but it still doesn't read the Rh wire.  Voltage meter reads 24 volts when connected to Nest,  I can hear the furnace motor power up but it doesn't kick in.  So I'm baffled.  Any help is appreciated.  

[MelbaDT]

Hi Wisky, 

Thanks for posting a detailed description of your concern and sorry for the delayed response. I want to dig deeper into this. 

A few questions — before installing your Nest Learning thermostat, did you check with our online Compatibility Checker if your system is compatible? If yes, are you getting a specific message or a code on your thermostat's display or Nest app? Also, could you provide a photo of the wires on the base of your thermostat so I can have it reviewed?

Best, 

Melba

[Wisky]

Hi Melba,

Yes I checked with compatibility before I purchased the Gen 3.  It is supposed to work with a 2 wire system with "power stealing" as opposed to a C wire.  Since I posted, the Nest is now reading the power wire but it is not recharging.  So I suppose it is not stealing any power to recharge.  I investigated the furnace connection and found that my particular furnace runs the thermostat via relays, so there is no "motherboard" that is labelled.  I think my only option now is to have the furnace reconfigured to allow a hard C wire.  I'll post a pic but it's a very simple hookup.