topic Re: AC not working in Nest Thermostats

AC not working

Dugant60 — Thu, 09 Mar 2023 15:38:15 GMT

I installed my nest, but it does not appear to control my AC. If i go to mode, there is only heat of Off.

Could my wiring be wrong?

Re: AC not working

Jenelyn_O — Mon, 13 Mar 2023 17:14:35 GMT

Hi Dugant60,

Thanks for reaching out and I'm sorry for the delay. I'd love to help.

It seems like your Nest Thermostat is configured for heating only. Your AC wire might not be properly inserted. Could you please share the photo of the wires connected to your control board and the wires you have on your old thermostat?

Best,

Jenelyn

Re: AC not working

Jenelyn_O — Thu, 16 Mar 2023 17:24:28 GMT

Hello Dugant60,

I wanted to follow up if you still need help. Please let me know if you're still having any concerns or questions from here, as I would be happy to take a closer look and assist you further.

Thanks,

Jenelyn

Re: AC not working

Dugant60 — Thu, 16 Mar 2023 19:58:17 GMT

Yes please, I recently installed my nest and it does not appear to have an AC mode.

Re: AC not working

Jenelyn_O — Thu, 16 Mar 2023 23:06:16 GMT

Hey Dugant60,

Thanks for the update! Could you please share the photo of the wires connected to your Nest Thermostat and control board? It will help us to move forward.

Regards,

Jenelyn

Re: AC not working

Dugant60 — Thu, 16 Mar 2023 23:13:37 GMT

I can't attach a photo?

Re: AC not working

Dugant60 — Fri, 17 Mar 2023 23:06:10 GMT

Re: AC not working

Markjosephp — Sat, 18 Mar 2023 18:33:59 GMT

Hello folks,

I wanted to stop by and see how I could help.

I appreciate your assistance here. Jenelyn.

@Dugant60, thanks for the effort you put into sharing your thermostat's wiring. It appears to be an incorrect wiring configuration, as the Y1 terminal is blank and no wire is connected. In most systems, the Y or Y1 wire controls your cooling system.

Could you also share with us a photo of your old thermostat's wiring? This will help us see how it was labeled. I'll look forward to your response.

Regards,

Mark

Re: AC not working

Dugant60 — Sat, 18 Mar 2023 19:11:22 GMT

Unfortunately I did not take a picture. I labeled the wires based off where the were in the terminal block. The two wires that dont directly correspond are W1 and RH. These wires were in the W and R terminals respectively (pretty sure I remember this correctly).

Re: AC not working

Markjosephp — Sat, 18 Mar 2023 20:03:34 GMT

Hey there,

Gotcha! By any chance, do you have a heating system? If you don't, try to reconfigure your system by moving the yellow wire to the Y1 terminal and the red wire to the Rc terminal. Also, restart your thermostat after the wiring changes.

Please note that you should turn off the power from your HVAC system at the breaker box before touching the wires.

Keep me posted on how it goes.

Thanks,

Mark

Re: AC not working

Dugant60 — Sat, 18 Mar 2023 20:14:22 GMT

I have a furnace and central air. Note, the both were operational from the previous thermostat

Re: AC not working

Markjosephp — Sat, 18 Mar 2023 21:00:08 GMT

Hello Dugant60,

Thanks for letting me know. If you both have the heating and cooling systems, your systems may still be Nest Thermostat compatible. However, with its current wiring configuration, it'll only work with your heater. Try to look for a spare wire that might be for your AC, but if there's none, it's best to contact an HVAC technician to inspect your system, look for the cooling wire, and reconfigure it.

Feel free to let us know if you have more questions.

Regards,

Mark

Re: AC not working

Dugant60 — Sat, 18 Mar 2023 21:33:55 GMT

How is it that the old thermostat was able to control both? I see there is a jumper on the R terminals on the old thermostat. Could that play a part?

Re: AC not working

Markjosephp — Sat, 18 Mar 2023 21:48:22 GMT

Hi Dugant60,

The Nest Thermostats do not require jumper wires because their displays include one. Your system might be configured to control both heating and cooling with one wire, but the Nest Thermostats require separate wires in order to control them separately.

Please take a look at this article and let us know if you need more help.

Regards,

Mark

Re: AC not working

Markjosephp — Tue, 21 Mar 2023 21:50:32 GMT

Hey there,

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

Thanks,

Mark

Re: AC not working

Dugant60 — Tue, 21 Mar 2023 21:53:05 GMT

No solution, I think I need to contact a HVAC company. It appears my AC and Heat are both controlled off one wire and the nest can't support this.

Re: AC not working

Markjosephp — Tue, 21 Mar 2023 23:01:36 GMT

Hello Dugant60,

Sounds great! Please make sure that you deal with a qualified professional who works with Nest products to avoid installation issues. Also, I'll lock this thread in 24 hours unless I can help you with anything else.

Regards,

Mark