Nest Thermostat error code 257

[InfiniteRebel83]

Hello my nest says I have an error code 257. I have a red, green, white, and blue wire for my system. The old thermostat had a spot for the blue wire. I have it in the OB slot. Does it need to be moved to the C slot?

[GabrielaG]

Hi @InfiniteRebel83,

Thank you for contacting the Google Nest Community. I'm sorry to hear your Nest Thermostat is having the 257 error code. I appreciate the details you provided me about your wiring. I'm glad to help you.

To make sure I provide you with the most accurate and effective troubleshooting steps, I just need a little more information. Could you please answer the following questions for me? 

• What type of Nest Thermostat do you have?
• What type of HVAC system do you have?
• When did you install your Nest Thermostat?
• Could you please send me a picture of the current wiring for your Nest Thermostat?

If you have any additional details that might be helpful, feel free to share them with me.

Regards,

Gabriela

[InfiniteRebel83]

So I managed to fix the problem. I had to go into the Google Home app and change what the blue wire was from OB to C and that fixed the problem. Then update wiring and bam problem solved. Thanks for the reply tho. 

[GabrielaG]

Hi @InfiniteRebel83,

Thanks for the update. I'm glad to hear that you resolved the issue with your Nest Thermostat by changing the blue wire from the OB terminal to the C terminal using the Google Home app.

If you have any further questions, please feel free to post.

Regards,

Gabriela