Wire a Nest for Lenox ECB40 Heat Pump

[jlreispro]

Good ady.

I am trying to wire my Nest up to replace a Lenox iComfort Thermostat on a ECB40 heat pump system (XP17 outdoor unit).  The board has screw downs for a typical thermostat installation plus the two sets of the four wire Lenox communication terminals.  I wired up W1, G, Y1, C, R, and O after removing them from the "Thermostat" connector (R I+ I- C).  The fan would kick on  but not the heat pump.  Forgot to save the error code it threw before I had to wire the old thermostat back in.

Looking for a little insight here.  Do I need to wire the "Outdoor Unit" R I+ I- C wires to the screw down terminals with the thermostat wires to get full functionality?  I have a newer Lenox unit with a Nest thermostat and that is how it is wired, though it was not a Signature Series unit. 

Any help would be greatly appreciated, especially since Lenox wants a first and second born child for a new thermostat.

Cheers and thanks,

JustinI added the O here.As originally wired

[zoeuvre]

Hi jlreispro, 

Thanks for posting here in the Community forum and for showing interest in our Nest Thermostats. Since we could not directly identify the compatibility of your Lenox ECB40 Heat Pump and Lenox iComfort Thermostat as your control board both has thermostat and outdoor unit wires, are you able to post a photo of how the thermostat wires are connected to your Lenox iComfort Thermostat? In that way, it will be easier for us to identify its compatibility with our Nest thermostats and to recommend the kind of Nest Thermostat best suited for your heat pump system. 

Also, you may use our Compatibility Checker so you can also determine if a Nest Thermostat is compatible with your heating and cooling system.

Keep us posted. I'll look forward to your response. 

Best,

Zoe 

[jlreispro]

I did go through the compatibility checker and it seems like the Nest should work.  The post reply will not let me post a picture of how the thermostat is wired.  Without a photo I can still say it is wired exactly the same as the wires coming off the board: R - Red, I+ - White, I- Blue, C - Green.

[jlreispro]

Well, now it lets me upload one...

[zoeuvre]

Hi there, 

Got it!. Since both your control panel and current thermostat have the non-standard labels of R, I+, I-, and C, which means that your system is proprietary,

Proprietary systems aren’t compatible with Google Nest Thermostats. However, some proprietary systems can be rewired by a pro installer to be compatible.

Let us know if that helps.

Thanks, 

Zoe