topic Re: Seven wires old system in Nest Thermostats

Seven wires old system

Vince4 — Thu, 14 Nov 2024 17:03:12 GMT

Old system have seven wires white for auxiliary black for emergency heat. 4th generation does not have a place for emergency heat just auxiliary. Confused where the white and black wire goes

Re: Seven wires old system

Starminder — Sat, 16 Nov 2024 14:43:08 GMT

Mine has the same wires/labels. Have you gotten anywhere with this?

Re: Seven wires old system

luciaaa — Tue, 19 Nov 2024 22:10:10 GMT

Hi there!

Thank you for reaching out to the community. I'd be glad to help with your wiring concerns. The information you've provided is very helpful for guiding you through the wiring process.

Based on this information, your system is compatible with the Nest Learning Thermostat (4th gen). You can install the wires in the following way:

Blue: C terminal.
Green: G terminal.
Yellow: Y1 terminal.
Orange: O/B terminal.
Red: Rh terminal (removing the jumper is not necessary with the Nest thermostat).
White: W1 terminal.
Black: Star (*) terminal.

Additionally, make sure the orientation for the O/B wire is set to "O."

Please let me know how it goes.

Best regards,

Ana

Re: Seven wires old system

Starminder — Tue, 19 Nov 2024 21:17:26 GMT

Mine is working, thank you!

Re: Seven wires old system

luciaaa — Wed, 20 Nov 2024 20:24:33 GMT

Hi, @Starminder,

Thank you for your response. I’m glad to know your thermostat is working with the wiring instructions I provided.

Feel free to reply if you have any questions.

Best regards,

Ana