Nest Thermostat to Honeywell EIM

[Nohartiii]

I want to replace my Honeywell thermostat that is only connected using 3 wires; Red, White and green to a nest thermostat.  My gas furnace also has a heat pump.  The thermostat wire runs from my thermostat to a Honeywell EIM.  The wires are connect to ports labeled 1,2,3 on the EIM and thermostat. unlike normal lettering in other thermostats.  

Please let me know if you have any suggestions.  

[David_K]

This Reddit post contains some info which reads to be useful for your situation:

Bypassing Honeywell Equipment Interface Module (HIM) for Nest Thermostat : Nest

[aatienza]

Hey Nohartiii,

I'd like to jump in here and check if you've seen davidking's response. Let us know if you need more help by replying to this thread.
 

I appreciate the help, davidking.

Thanks,

Archie

[aatienza]

Hey there,

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

Thanks,

Archie

[aatienza]

Hello there,

Just checking in to make sure that you've seen our responses. Please let me know if you have other questions or concerns as I will be locking this in 24 hours if I won't hear back from you again. Feel free to start a new thread and we'll be happy to help.
 

Thanks,

Archie

[Nohartiii]

Thank you I have found that the Nest E will not work with the Honeywell EIM without losing the benefits of the system.  The Nest Learning Thermostat 3rd Generation will be able to run my HVAC system.  

[Jhonleanmel]

Hi folks,

Nohartiii, awesome — glad to hear that your query is cleared. It looks like we can consider this one complete, so I will lock the thread shortly unless I can help out with anything else.

Best, 
Mel