Is my thermostat compatible with nest learning thermostat?

[Checkford]

I have three wires that are connected to W G and R - is this compatible with the learning nest thermostat?

[David_K]

Yes, your system should be compatible with Nest Learning Thermostat 3rd or 4th gen, or Nest Thermostat E if you're in the UK or EU.

[Patrick_Caezza]

@Checkford 

Post a picture of the original thermostat's wiring