topic Re: Nest 3rd Gen Install A/C blows hot in Nest Thermostats

Nest 3rd Gen Install A/C blows hot

Wellidas — Sat, 22 Jun 2024 11:45:21 GMT

Hello

I bought a Nest 3rd Gen Thermostat to replace my Emerson Sen Si .As you can see below I hooked up the wires, However the System only blows hot air.

I installed the old one back the A/C works just fine.

Can someone help me with these wires? the confusing ones is the Black Y2* and the white WE wire?

Re: Nest 3rd Gen Install A/C blows hot

Wellidas — Sat, 22 Jun 2024 11:53:53 GMT

Here are the pictures of the old thermostat and the new Nest wired up but blowing hot air only.

Existing Thermostata

Wires from the old one prior to disconnect

Nest Wired, but only blowing hot air

Re: Nest 3rd Gen Install A/C blows hot

luciaaa — Tue, 25 Jun 2024 17:10:41 GMT

Hi @Wellidas,

Thank you for posting in the community and sharing the pictures with us. I'm truly sorry your current thermostat isn't blowing hot air, I'm happy to help!

Here's how to connect the wires to your Nest Learning Thermostat (3rd generation):

Red wire goes to RC
Orange wire goes to O/B
Yellow wires goes to Y1
Green wire goes to G
White wire goes to star connector (*)
Blue wire goes to C
Black wire goes to Y2

Let me know how it goes.

Keep me posted,

Ana

Re: Nest 3rd Gen Install A/C blows hot

Wellidas — Tue, 25 Jun 2024 21:10:52 GMT

Hello,

No Luck, still blows only hot air. When I install the old one back A/C works perfectly. 😭

Re: Nest 3rd Gen Install A/C blows hot

luciaaa — Tue, 25 Jun 2024 22:09:34 GMT

Hi @Wellidas,

Thank you so much for your response. I'm truly sorry to hear that your system is still blowing hot air. I'm happy to help!

To better assist you, could you please share a picture of your current wiring configuration?

In the meantime, I recommend performing a factory reset on your thermostat:

Settings > Reset > All Settings > Reset

Please let me know how it goes.

Best regards,

Ana

Re: Nest 3rd Gen Install A/C blows hot

Wellidas — Tue, 25 Jun 2024 23:58:37 GMT

Hello,

This set up here is what works with current thermostat a Emerson Sen si
THIS SET UP WORKS

Re: Nest 3rd Gen Install A/C blows hot

Wellidas — Wed, 26 Jun 2024 14:35:53 GMT

Also here is the set up I was advised on earlier, also it does not work. A/C does not blow cold air

NEST WIRED UP NO GOOD

Re: Nest 3rd Gen Install A/C blows hot

luciaaa — Wed, 26 Jun 2024 15:58:55 GMT

Hi @Wellidas,

Thank you so much for the pictures. I'm so sorry to hear that after troubleshooting, your system is still blowing hot air. I'm happy to assist you further.

Since you've already completed the wiring configuration and factory reset, I recommend changing the orientation of the O/B wire.

Please let me know if this helps.

Best regards,

Ana.

Re: Nest 3rd Gen Install A/C blows hot

Wellidas — Thu, 27 Jun 2024 00:47:53 GMT

Hello,

I changed the O/B Wire as instructed, the system now works just fine.
Thank you for your support.

Re: Nest 3rd Gen Install A/C blows hot

luciaaa — Thu, 27 Jun 2024 15:11:12 GMT

Hi @Wellidas,

Thank you so much for following all the steps. I am glad to hear your AC is working now.

Have a wonderful day!

Best regards,

Ana