Converting from a Lennox iComfort - 10F81 to Nest Learning Thermostat

[Renjiz]

Hi All,

I have two separate HVAC units at home both of which were on the Lennox iComfort - 10F81 thermostat. The first one conked off in fall 2021 and the technician could not find a replacement and finally replaced it with a basic Emerson thermostat (I did not see him bring through any new wires etc but not sure if he did some adjustments up in the attic). I was able to work with Nest support to replace it with a Nest Learning Thermostat. (See pics of wiring to Emerson, custom wiring for Nest Learning thermostat - https://photos.app.goo.gl/Xt8Y4Moon8MWeD8E9 ) This is working fine.

Issue - My second Lennox iComfort - 10f81 is now failing and Nest support is unable to give me a custom wiring diagram. I have the same model Lennox HVAC unit. I am giving the current wiring at the thermostat, HVAC and HVAC model here - https://photos.app.goo.gl/cV3sBJEcgkAdtKqT9 ) Can someone help and tell me if I can follow the same custom wiring followed at the first unit above?

Do I need to get the service of a Technician in this instance? Would I damage the Nest or my system if I try to connect incorrectly?

[EdwardT]

Hi Renjiz,

Thanks for reaching out. It looks like your Lennox iComfort has proprietary wiring. I highly suggest getting a Nest Pro to install your Nest Thermostat to make sure that it's wired correctly and to avoid damage on your system. You could click on this link to learn more about our Nest Pro services.

Thanks,

Edward

[EdwardT]

Hi Renjiz,

It's me again. I wanted to check back in to see if you have other questions and concerns. Feel free to let me know if you do. 

Thanks,

Edward

[EdwardT]

Hi Renjiz,

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

[Renjiz]

Thank you Edward, I will contact Nest Pros to take this forward. As I mentioned since an exact same set up was converted, I was hoping I would luck out but it is safe to bring in the experts on this one. 

[EdwardT]

Hi Renjiz,

Thanks for the response. Let us know once you got them to install your Nest Thermostat and if you have other questions. We're always glad to help.

Thanks,

Edward

[EdwardT]

Hi Renjiz,

It's me again. I wanted to check back in to see if you have other questions and concerns. Feel free to let me know if you do. 

Thanks,

Edward

[EdwardT]

Hi Klink,

Thanks for reaching out. It also looks like it's using proprietary wiring. I highly suggest getting a Nest Pro to install your Nest Thermostat. Please click on this link to learn about our Nest Pro services.

Thanks,

Edward

[Klink]

I am also trying to replace a Lennox iComfort thermostat with a Nest Learning Thermostat. The iComfort uses unique i+ and i- terminals that I am not sure what to do with. I will attach photos of the  connections at both ends. 
https://photos.app.goo.gl/RX8ZWzzjPpu7MUuB8
https://photos.app.goo.gl/m2r94yPrQJCgwmsW6

[Klink]

The markings right to left are

R  i+  i-  C

[ACSM59]

I have the same issue.   It seems like I+ and I- are proprietary to Lennox communications to control the fan and the 2 stage cooling and heating.    I too would like to replace my thermostat with a nest.   I am trying to figure out what re-wiring needs to be done, but so far I had no luck.   If you find how, please let me know.

[EdwardT]

Hi ACSM59,

Thanks for posting. I would highly suggest to get it physically checked by a Nest Pro. You can find the link from my previous response.

Thanks,

Edward

[MelbaDT]

Hey there, 

Checking back in — we hope you've reached out to a Nest Pro technician to have everything checked. Feel free to reply back should you have more questions about this. 

Best, 

Melba

[MelbaDT]

Hi, 

We haven't heard from you in a while so we'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

[Klink]

I also have these unused connections on the board. Not sure if they can be used. 
https://photos.app.goo.gl/4SDbeRZ63aq8fvzn8