09-01-2021 06:23 AM
Heat using thermopump and fan (for circulation not working)
Furnace Lennox CBX27UH-036-230-6-02
Thermopump Lennox XP14- 030-230-09
Replacing Lennox thermostat X4147
(with Air Exchanger)
Lennox System is an O (reverse valve energized on cool. As is most often the case in Canada, you never want to be without heat if it fails)
A few days ago Nest 3rd gen thermostat in my home to replace my failed Lennox thermostat. I used the online tool and mapped my old lennox connections to those suggested by the Nest tool, but my HVAC system is not fully functioning. AC using thermopump and secondary or emergency heat work, but heat using thermopump and fan only (for circulation does not, although Nest thermo shows fan as working)
My local HVAC suggested the pic below with the handwritten instructions. In speaking to others it seems I can also connect the white to "W2/AUX". In addition to the low temp deep freeze cut off, my thermopump also has a manual adjustment within the thermopump to adjust low temp cut over (can I bypass the "Dual Fuel" within the Nest, just concerned having both my pose a conflict?)
Below are some pics of:
1. My existing Lennox Thermostat wiring
2. Lennox wiring diagram
3. My furnace connections (note I have a air exchanger and humidifier as well so it could look strange to some), but you can see its basic. The Green Wire (FAN) may look odd, but it loops to my air exchanger (grouped within box) and yes installer should have used a Green wire to terminate, but they figure nobody will ever see it.
4. Nest suggested wire mapping using install module within app
5. My current Nest wiring
6. Pic with handwritten note suggested wiring from my HVAC guy who only really installs Lennox thermostats (dont want to go against what Nest install app advised me to do and damage the Nest or worse my eqpt)
09-16-2021 03:12 PM
I'm so sorry for the delay in our response, but I wanted to hop in here to make sure we addressed your concern. I can definitely understand the confusion when it comes to thermostat issues as it can be very odd to figure out sometimes, but I'm happy to look into this for you.
First off, I would suggest using the Compatibility Checker to see if your system is compatible. Then, if it is, I would suggest contacting a pro to come out to help you with this since I know that the Nest thermostat is not compatible with stranded wires, every wire has to be connected to the Nest Thermostat system.
Please let me know if you have any further questions or concerns as I'm happy to help.
09-20-2021 03:24 PM
Just wanted to jump in here to check to make sure that you saw our response. Please let us know if you have any other questions or concerns as I will be locking this in 24 hours.
Have a great day.
09-21-2021 03:18 AM
Thanks GarrettDS for the suggestion, but I have already used the compatibility checker and everything checked out (as well the wires terminating at the thermostat are the standard set up) . I have installed many thermostats over the years without issue until the Nest and I have no intention of spending more to bring in a nest pro. Luckily for me I am still within my return window so I will likely be returning and going with another non nest model. Thanks again for your help.
09-24-2021 01:56 PM
Thank you for your patience with us! We've created a case for your issue to send to our support team. Be on the lookout for an email from us in your inbox soon. For reference, your case number is 1-5024000032152.
09-27-2021 11:18 AM
I just wanted to reach out and see if you are still in need of any help? Please let me know if you have any trouble seeing the email from our Team about your Case.
09-29-2021 11:37 AM
Its been a few days since the last reply and I am going to lock the thread at this time. If you have any questions from here, please feel free to create a new post.