Wiring compatibility

[Gusov]

 hi everyone,

My old thermostat has 6 wires, can someone please help me out to connect them to the nest thermostat? 
this is what google support told me to do: 

Yellow - Y

green - G

blue - C 

white - W

orange - O/B

red - R

when I connected all of them to nest, it shows me C wire not detected. Am I doing something wrong?

[MT2220]

It is possible that if your original thermostat didn't use the blue C wire, then it's not connected to your air handler.

That would mean you don't have the 24v needed to use the Nest thermostat. 
That's just a possibility. 

[zoeuvre]

Hi folks, 

@Gusov, thanks for reaching out to us, and I'm sorry to hear about the situation. Let's sort this out.  

Are the thermostat wires seated properly on their terminals with no loose or exposed wire? What is the exact message or code you're seeing on the thermostat? Also, please collect the power readings of your Nest Thermostat 2020 under its Settings > Equipment > Power Info (VIN, IIN, PS-*). 

I'll look forward to your response.

I appreciate your help, @MT2220. 

Best,

Zoe

[zoeuvre]

Hi Gusov, 

I want to check and see if you are still in need of any help. Please let me know, as I would be happy to assist and answer any questions you may have.
 

Thanks,

Zoe