topic No cool mode in Nest Thermostats

No cool mode

Nestoronto — Fri, 13 May 2022 03:59:37 GMT

Hello,

New install. Heat works well but there is no cool mode. Not sure about the wiring perhaps

Current thermostat

old thermostat

Re: No cool mode

Patrick_Caezza — Fri, 13 May 2022 04:49:23 GMT

You don't have a cooling mode because you don't have a Yellow (Y) wire. Your original thermostat was wired for heating only.

Re: No cool mode

Nestoronto — Fri, 13 May 2022 11:27:38 GMT

Hello, thanks for the reply. The a/c worked with the old thermostat though.

Re: No cool mode

Bzink — Sat, 14 May 2022 00:46:24 GMT

I have the same issue and can’t find information to fix it.

Re: No cool mode

Nestoronto — Sat, 14 May 2022 00:52:03 GMT

Hey,

So I checked the board on my furnace and it turns out that the black wire is connected to the y on the board. So I connected it to the Y on my best and now the cooling is working. But now there is nothing connected to C on the thermostat so not sure what that would mean for the function of the NEST

Re: No cool mode

Bzink — Sat, 14 May 2022 02:05:22 GMT

Thank you, I will take a look!

Re: No cool mode

Patrick_Caezza — Sat, 14 May 2022 07:52:53 GMT

Having the C wire installed means that the thermostat is powered by the HVAC system all of the time and does need to use the batties except during a power outage.

I always install a C wire when I install any thermostat. It always helps stop any problems down the road.

Re: No cool mode

Nestoronto — Sat, 14 May 2022 14:25:20 GMT

I agree and that's what I was hoping for when I installed it originally. However the black wire on the furnace board was attached to Y and when I did the same it turned the ac on. But I appreciate your reply and I will have to figure out a way to install the c wire from the furnace to the thermostat.

Just as an aside, what issue should I expect with out the c wire in the mean time

Re: No cool mode

Ryan_G — Sat, 21 May 2022 21:21:00 GMT

Hi Nestoronto,

Thanks for reaching out here in the community.

Nest thermostats are designed to use very little power, and in many cases they can use your system’s heating and cooling wires to get enough consistent power. But sometimes, you may need to connect a common wire (C wire) or power accessory to prevent some problems like low battery message or Wi-Fi disconnection problem.

Check out this link to know more about it.

Thank you for your help, Patrick_Caezza.

Best regards,

Ryan

Re: No cool mode

Ryan_G — Tue, 24 May 2022 22:47:12 GMT

Hey Nestoronto,

I just wanted to follow up and see if you're still in need of help. Please let us know as we would be happy to answer any questions you may have.

Best regards,

Ryan

Re: No cool mode

Ryan_G — Wed, 25 May 2022 22:48:58 GMT

Hey Nestoronto,

Thanks for being here in the Google Nest Community.

I'd like to bump in here and make sure that you’ve seen our response.

Please let us know if you have any other questions or concerns as I will be locking this thread in 24 hours.

Have a great day.

Best regards,

Ryan