Too many wires in the legacy system

[NYCApartmentGuy]

I was helping a friend install nests. My friend as different legacy thermostats. One had letters and I was able to wire it up and it works great. Unfortunately the other thermostats (they are all the same) has too many wires and has numbers not letters. I am not sure which wire maps. I have too many yellow wires for example. 

[Markjosephp]

Hello NYCApartmentGuy,

Thank you for taking the time in letting us know about your inquiry and for helping your friend.

Based on the thermostat wiring diagram, it appears that they have a proprietary system. This type of system isn't compatible with Google Nest thermostats. However, some proprietary systems can be rewired by a pro installer to be compatible.

If there’s anything else I can help you with, please let me know.

Best regards,

Mark

[EdwardT]

Hi NYCApartmentGuy,

I wanted to follow up and see if you are still in need of any help. Please let me know if you are still having any trouble from here, as I would be happy to take a closer look and assist you further.

Thanks,

Edward

[EdwardT]

Hi NYCApartmentGuy,

I'm just checking in to 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 in 24 hours.

Thanks,

Edward