Getting an N261 error

[4everLSU]

Need help!! I keep getting this N261 message. I only have 4 wires with my system, which is old! I am attaching 3 pics for someone who can help. 

The issue is with the blue wire. I'm not sure where it should go with this new Nest Thermostat. I've connected it to both the C connector and the OB connector, which was suggested in an online article. Each time, it tells me I have an equipment error and is N261. As you can also see in the old thermostat's picture, there is a jumper wire (silver) which I have circled between R and RC connectors.

I'm so confused .. and I do have some knowledge of electrical issues.

PLEASE HELP SOMEONE!

[BrianGS]

Hi @4everLSU,

Thank you for posting in the community. I’m sorry to hear you're experiencing an N261 error code on your Nest Thermostat and are having difficulty identifying the correct placement for your blue wire. I understand how frustrating it can be to deal with power errors, and I appreciate you providing the details about your previous wiring setup and the jumper wire. I'm happy to assist you.

To further assist you, could you please provide the following information?

• What model of Nest Thermostat do you have? This article might be helpful: How to tell which Nest thermostat you have.
• Could you please provide a photo of the wiring configuration for the previous thermostat, if you have one?
• Could you also provide a photo of where those wires connect to the control board inside your HVAC system? 

Please keep in mind your HVAC system uses high voltage. Before opening any panels to check the control board, please make sure to turn off the power to your system completely at the breaker. The control board is usually located inside your furnace or air handler.

If you do not feel comfortable performing these steps, I recommend contacting a local HVAC technician for further assistance.

I look forward to your response.

Best regards,

Brian