topic Re: Wires for Thermastat Compatibility in Nest Thermostats

Wires for Thermastat Compatibility

MVP_Home_Sales — Sat, 23 Apr 2022 23:25:31 GMT

Need Help Determining if I can use a Nest Base Thermastat on this. I have a C wire on the one and don't on another is the less expensive nest thermostat compatability with both these systems?

Re: Wires for Thermastat Compatibility

Patrick_Caezza — Sun, 24 Apr 2022 02:11:38 GMT

I'm not sure what you mean by having a C wire on one and not the other.

Re: Wires for Thermastat Compatibility

MVP_Home_Sales — Sun, 24 Apr 2022 11:05:56 GMT

The C wire is Blue on a newer system with a Honeywell and the older system has a Nest learning Thermostat without a C blue wire and had been running. It's my understanding that the blue wire C supplies voltage for the Thermostat. So my question is if I can use the less expensive nest thermostat without a C wire on either of the hookups shown ?

Re: Wires for Thermastat Compatibility

MZellmer — Sun, 24 Apr 2022 11:22:55 GMT

Though I'm not sure about the specifics of your application, I have read a number of posts in several forums regarding the lack of the C wire. Many of these posts have suggested powering the thermostat with a doorbell like transformer to essentially provide the power without an actual C wire. I was able to get two Nest learning thermostats to work well on a 2-zone system without C wires. Have description/pictures posted elsewhere in this community.

Re: Wires for Thermastat Compatibility

Patrick_Caezza — Mon, 25 Apr 2022 00:35:35 GMT

Ah, you have two separate thermostats. I get it.

Do you have two separate HVAC systems or do you have one system with a zone controller?

You can use any of the Nest thermostats, you'll need to add a C wire to the Nest Learning Thermostat if you change it over to the Google Nest Thermostat. I personally always install a C wire if one isn't present and you can do it by using a spare wire if there is one or use the Nest Power Connector.

Re: Wires for Thermastat Compatibility

MelbaDT — Fri, 29 Apr 2022 03:36:38 GMT

Hey folks,

Thanks for answering, Patrick_Caezza.

MVP_Home_Sales, I'm chiming in to check if your questions were answered. Let us know if you have more in mind.

Best,

Melba

Re: Wires for Thermastat Compatibility

MelbaDT — Tue, 03 May 2022 07:25:36 GMT

Hey there,

Checking back in if you still need our help here. Feel free to reply back to this thread.

Best,

Melba

Re: Wires for Thermastat Compatibility

MelbaDT — Thu, 05 May 2022 02:21:54 GMT

Hi,

I haven't heard from you in a while so I'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

Re: Wires for Thermastat Compatibility

MVP_Home_Sales — Thu, 05 May 2022 11:56:31 GMT

Thanks I don't have a c wire on the unit in the one home that's why I was asking . Wanted to take the learning thermostat which is currently working without a c wire and move to new home. But wanted to replace with less expensive one . So after looking this over I went with the pro version Nest E as I heard it is similarly powered as the learing one without the c wire. Does anyone know if that will work without the c wireless thelearni g one?

Re: Wires for Thermastat Compatibility

Ryan_G — Wed, 13 Jul 2022 00:41:57 GMT

Hi MVP_Home_Sales,

Thanks for being here in the Google Nest 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, like the Nest Power Connector, to make your system compatible.

Unlike other wires connected to your thermostat, a C wire does not control heating or cooling functions. It only provides constant power to your thermostat.

You could check out this link to know more about C (common) wire.

Best regards,

Ryan

Re: Wires for Thermastat Compatibility

Ryan_G — Mon, 18 Jul 2022 20:38:24 GMT

Hey folks,

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