[bmelton]

Having had this happen with at least two plain ol' thermostats, my fix for those was to go down to Lowes, pick up a $10 thermostat until I'd gotten my more expensive models repaired.

I'm not personally familiar with the Nest, but is there some change to the architecture that precludes you from doing that as a stopgap?

[dangrossman]

No, it's just a normal thermostat, snaps on to a back plate with the same wires as they all do. You can swap your old thermostat back on in minutes.