Nest Learning Thermostat Compatibility Wiring Question

[cabindream]

Hello

I am trying to find out if the Nest Learning Thermostat will work for my American Standard Heating & Cooling system. I know it has a heat pump. I can supply more info on the system if that helps

The wires I have are 

Top Row
X1   C   L   X2   OT   OT

Bottom Row
R   W2   E   W1   Y1   O/B  (orange wire) G

Here is a link to an image of the existing thermostat - https://drive.google.com/file/d/1VM5Q7GgAZN8jFeR6_h3UHgk-O3vaTy4k/view?usp=sharing

Many thanks

[cabindream]

comment removed

[luciaaa]

Hi, @cabindream,

Thank you for posting in the community. I'm happy to assist you further with your compatibility query.

Based on the image you provided, your system may be compatible with the Nest Learning Thermostat (3rd generation). However, definitive compatibility can only be confirmed by a Nest Pro technician. 

Many heat pump systems have multiple heating and cooling stages. The additional OT wire and the presence of W2, E, W1, and O/B wires suggest this might be the case for your system. A Nest Pro will be able to determine the correct installation process.

Keep me posted.

Best regards,

Ana