Honeywell to Nest compatibility

[Stacyk18]

 We were gifted a nest thermostat from our realtor for our new build home. The home currently has a Honeywell pro series. When I looked at the wiring, we have 2 more wires than the nest we were gifted so it is not compatible. Are there any that are? 

When I try to look up compatibility and spoke to chat support, they were not able to tell me if any were compatible. 

https://photos.app.goo.gl/zcLzGTvzAkhdnQhC8

[AxelD]

Hi Stacyk18,

Thanks for posting! I can definitely help you with the wiring configuration. Checking the photo you posted, it looks to be compatible with the Nest Thermostat you have. The BROWN WIRE and the BLACK WIRES, those might be for a Dehumidifier or something similar. Could you confirm this? However, you can still use your thermostat without those. If you want to use them, my recommendation would be to get a Nest Learning Thermostat which has more ports to connect other wires.

Here you have a wiring suggestion:

Let me know how it goes.

Regards,

Axel.

[jgfire510]

Hi Axel,

Maybe you can help. I currently have a honeywell RTH6300B 1005 thermostat. I have a wall hung  Navian boiler with no cooling and 1 zone. I have a white wire on the W and a red wire on the R. Thats it. I am looking to get the google nest learning thermostat through PSEG. Now, I have a green, blue and yellow in the wall not being using. Do I need a C wire and are the extra colors wires a c wire?

Thanks

Jeff

[AxelD]

Hi jgfire510,

Thanks for posting in the community! Sure, I can help you with this compatibility check. Based on the information provided about your wiring, it should be compatible with the Nest Learning Thermostat. It's always recommended to install a C-WIRE or a Nest Power Connector to provide enough consistent power. In most of the systems these are the function for each wire described in yours:

• Red: Power
• White: Heating
• Green: Fan
• Blue: 24V Common wire
• Yellow: Cooling

Do you know what all these wires in your system are for?

Keep me posted.

Regards,

Axel. 

[jgfire510]

Hhhhhgg

[jgfire510]

Hi Axel, This is my current set up. only 2 wires needed and the 3 that are not being used. Will the Learning thermostat work without a C wire or can the 3 unused wires act as a c wire, or can the current red wire be enough to power the new thermostat for the wifi? I am not gonna hire someone to add a c wire.

Thanks

Jeff

[AxelD]

Hi jgfire510,

Thanks for replying and providing those photos! Checking them, I noticed that those three wires aren't connected, so you can leave them like that. Also, you can try to use your Nest Thermostat without the C-WIRE and see how it works. If you install it without one and you notice you're facing any WiFi issue, it'll be needed. Not all the systems require one, but it's always recommended to provide constant power to the thermostat. 

Regards,

Axel. 

[jgfire510]

Hey Axel, 

So pretty much my red wire will power the learning thermostat but not sure if there is enough to power the wifi as well. I imagine I will only know this as I try to set up wifi. If the wifi does not work, then I got a new thermostat for 8 bucks i guess.

So the c wire can be directly installed through the wall up to boiler or a c wire with an external power adapter for the  wall plug if I wanted.

Is that all about right?

Thanks

Jeff

[AxelD]

Hi jgfire510,

Thanks for replying! That's right! You can get either a C-WIRE from your HVAC board to your Nest Thermostat's base installed by a Pro Technician or getting a Nest Power Connector that can be installed on your own. These two are the recommended options. 

Best regards,

Axel. 

[jgfire510]

Hi Axel,

I did order it. Eventually when I get and install, I will follow up and let you know so you can help others.

Thanks so much

Jeff

[jgfire510]

Hi Axel,

Hope you are well.

I did receive the new thermostat and have a question. It did not come with a guide so the online support for Power (C, RH, RC, R). On the actual unit there is a RH and RC but no R by itself so which is for power? For heating there is Heating: 1, 2, and 3 stages (W1, W2, W3), I assume I would use W1 cause I have a one stage boiler. My existing is a white wire going into W which is the heat .

Thanks

Jeff

[AxelD]

Hi jgfire510,

Good to hear from you! I checked the photos and your system only has two wires. Since your system appears to be set up for heating only, if the red wire is connected to the unit's "RH" terminal, please use that one and connect it to the "RH" terminal on your Nest Thermostat as well.

Regards,

Axel. 

[jgfire510]

Hey Axel,

So good news. everything is connected, set up went well, Downloaded the app for final set up and it connected to my home network with ease. Now I do realize there could be issues with wifi if the power is not sufficient but we will see what happens in the future. The heat function is off and the boiler is making hot water like it is supposed to.

I do appreciate all your help

Thanks

Jeff 

[YL1]

Hey Axel, I have the same issue with the Honeywell humidistat that I would like to switch for the Nest thermostat as stand-alone, but my issue is the diagram on the Honeywell includes two wires U, which i think are for humidifier and dehumidifier and two S for sensor , i have no idea how to link them on my Nest 

[pereztzum]

Hi there!

Thank you for reaching out about your Honeywell humidistat and Nest thermostat. The dual U and S wires on the Honeywell indicate it's likely designed to control both a humidifier and dehumidifier, which can complicate the transition to a Nest thermostat.

To provide the best possible solution, I'll need some additional information:

• A clear picture of the wiring connections on your Honeywell humidistat.
• The specific model of your Nest thermostat.

I recommend checking the Nest compatibility tool on our website. It can provide tailored guidance based on your system's configuration.

If you're unsure about the wiring or want to ensure a seamless installation, I strongly recommend contacting a qualified HVAC technician. They have the expertise to safely and correctly connect your Nest thermostat to your HVAC system.

Regards,

Brandon.

[YL1]

[YL1]

Nest learning thermostat third gen

[chaconmorales]

Hi YL1,

Thanks for reaching out to the Community. I am sorry that you are having issues with your thermostat compatibility and installation. But no need to worry, help's here!

Based on the information and the picture provided, your Nest Learning Thermostat might be compatible with your system, however you may need to contact a Nest pro and have them check your system to confirm if it is compatible.

You can also check the following article to verify your Nest thermostat compatibility.

Please keep me posted. 

Best regards,

Mario

[YL1]

Thank you but I would like to do the installation myself 

my question was based on the picture do you think the best can be used as humidistat stand alone 

[chaconmorales]

Hi YL1,

Thanks for following up. I am sorry if the information provided was incomplete or confusing. Let’s check it out!

As I mentioned before based on the picture posted, your system is not compatible with the Nest Learning Thermostat, however you may need to contact a Nest pro and have them check your system to confirm if it is compatible. In some cases it is necessary to rewire or check the best wiring configuration for the devices to avoid causing any damage in the system. Based on that, you may not be able to use it as a "humidistat" stand alone. 

You can also check the following article to verify your Nest thermostat compatibility.

Please keep me posted. 

Best regards,

Mario