Nest E wiring check

[girsh]

I know my nest E isn't compatible (only supports 3-stages when I have 4-stage 2 heat 2 cool geothermal)

I want to leave off one of the stages and see if I can make it work, but the original wiring for my system isn't making sense

Old (Pro) Wiring: https://imgur.com/a/i1Wb76f

New (Amateur) wiring: https://imgur.com/a/0ePs2mA

I originally had the white wire in W (seemed conventional), but it was running my bill up by using only the backup heater.

[Patrick_Caezza · Accepted solution]

@girsh 

You have a Google Nest Thermostat (2020) not a Nest Thermostat E.

Geothermal is a form of heat pump and should be wired as one.

Try this wiring

Black - L - Tape Off

White - AUX/E - W (set as AUX heat)

Green - G to G

Orange - O/B to +/OB

Blue - C to C

Yellow - Y to Y

Red - Rc to R (jumper to R not needed)

[girsh]

@Patrick_Caezza 

That all makes a lot of sense, got a few light bulbs going off reading your post. I've wired it up as such, thanks a ton