Nest Compatability with Honeywell with 3 wires

[PatB1]

I believe I need to buy a wire to put on my furnace to make this wiring compatible? Does anyone have experience with this?Honeywell 7 day digital program RTH8500D?

[Patrick_Caezza]

It looks like the terminal block is labeled 1, 2, 3 which mean it's not compatible with any of the Nest thermostats as it is using a proprietary interface

[MelbaDT]

Hey folks, 

Appreciate your answer, Patrick_Caezza. 

PatB1, could you confirm if the terminal blocks are indeed labeled as 1,2,3? If it is, I'm afraid that you have a proprietary system which is not compatible with Google Nest thermostats. However, some proprietary systems can be rewired by a pro installer to be compatible. Take a look at this link to know more about our Nest thermostat compatibility: https://bit.ly/2KOTqgW

Best, 

Melba

[PatB1]

Unfortunately they are indeed labelled 1,2,3.

Does this mean to proceed with Nest I would need a professional install, pulling out the main unit on my furnace?

[Ryan_G]

Hey PatB1,

Thanks for your update.

With the wire labeled 1,2,3, your unit is a proprietary type of system and it is not compatible with Nest Thermostat.

Like what Melba has mentioned, it can be checked by a Nest Pro and there's a possibility that it can be made compatible with professional installation.

I hope it helps,

Ryan

[Ryan_G]

Hey PatB1,

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

[Ryan_G]

Hey there,

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