Replacing Lennox iComfort thermostat with Nest

[Majones77]

My old thermostat (Lennox iComfort) has 4 wires, Red, Yellow, White, and Blue(C). However, the Yellow is connect to terminal identified as i+ And White is connected to i-.  I hooked up the Nest Learning Thermostat and it would not start my AC system. Is there a work around to be able to use existing wiring with Nest?

[Apop]

I took a picture of my wire connections before I removed my old thermostat I had a total 6 wires Blue wire / C wire was not connected, my Yellow wire  was connected Y on the old thermostat, the Nest has Y1 and Y2, I connected to Y1, no problem turning on or off with the Nest

[Ryan_G]

Hi Majones77,

Thanks for reaching out here in the Google Nest Community.

I'd like to jump in here and check if you've seen Apop's response. You could also share a photo of your current wiring configurations for us to further assist you.

Thanks for sharing your thoughts here, Apop.

Regards,

Ryan

[MelbaDT]

Hey there, 

Checking back in — how's it going? Still need our help here?

Best, 

Melba

[MelbaDT]

Hi, 

We haven't heard from you in a while so we'll be locking this thread if there is no update within the day. If you have any new issues, updates or just a discussion topic, feel free to start a new thread in the Community.

Best, 

Melba