u/AcceleratedCrawfish

I got my Mom a Ecobee Premium and am planning to install it tomorrow. I think I have all the wiring sorted out aside from the white wire. This is a picture of her current thermostat wiring on a heat pump system. I believe the orange in the terminal labeled W on left and O/B on the right should go on the O/B terminal on the Ecobee. So then should the white wire currently connected to the W2/Aux-E go in W2 on Ecobee or W1?

Thanks.

https://imgur.com/cwsymj5

I want to buy my mom a smart thermostat for Mother's Day to make things easier for her to manage her climate control. She sent me this picture of the wiring so I am wondering if the blue wire is a common wire. She wasn't comfortable taking the front off her main unit to take pictures of it. But I know that it is only about 10 years old.

If not will one of those C-wire adapter kits work?

Thank you for your time.