Why is my house not compatible with nest thermostat?

[JRJones]

Just trying to install the thermostat today, all is telling me the system is not compatible.

[JRJones]

Here is my current wiring Here is my current wiring  

[Markjosephp]

Hello JRJones,

Thanks for posting here in the Google Nest Community!

It appears that you're having some trouble with the compatibility of your Nest Thermostat and your existing thermostat. Based on the information you've provided about your current wiring setup, it looks like your thermostat has the following connections:

• Y2 (orange)
• W2/Aux (brown)
• R (red)
• W (white)
• Y (yellow)
• G (green)
• C (blue)

With your thermostat's setup, it's compatible with the Nest Learning Thermostat to accommodate the second stage of heating and cooling. To double-check, is your system a heat pump? If so, the white wire should be on the O/B terminal to the Nest Thermostat and follow your existing thermostat's wiring setup for proper placement of wires.

Let us know if you have more questions.

Best regards,
Mark

[JRJones]

We have the basic Nest thermostat which I think may be a different model? There are only 6 terminals on the back of the thermostat and I have 7 wires.

[Markjosephp]

Hi there,

Thanks for letting me know. Given the wiring configuration you have with your system, the Nest Learning Thermostat is the only one compatible with it to support your multi-stage system.

Please check out the Identify a Thermostat Wire article and let me know if you have more questions.

Warm regards,
Mark