Help with Trane Thermostat Wiring

Have a Trane Air handler and the internal board has the following connections in the 1st picture. ! do not have a C wire so which wire do I use. Also, in the 2nd picture from my thermostat I see an X2 terminal but in the app there is no X2 listed to choose. Any assistance would be appreciated!


Welcome to the forums! Do you have a heat pump? I am no HVAC pro but the bottom row look to be the heat pump terminal points, and then the top labels are the normal heat/cool terminal points? Reference the row labels on the right. Looks like the x1 is labeled y2 on top maybe? Is that point available during setup?

Anyone in the know able to chime in here?

Hi Thanks so much! I live in Florida so yes it’s a heat pump so its the bottom letters. During setup the app does not give a X2 option but the compatibility checker online does give that option. Its a bit confusing and then when I look at the terminals on the air handler main board its even more confusing…no C wire?
Here is what the main board looks like.

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I believe I’ve seen C also labeled as B, but @speadie should be able to help clarify


For a Trane heat pump, B is common (C), and X2 is emergency heat (Aux or *)


Great! So how should I hook up X2 to the Wyze thermostat? The app gives zero direction?

Thanks a bunch!

Tell the wyze that your X2 wire is an E wire and it will tell you how to hook it up.


will do and let you know thanks!


got a chance to hook it up yesterday and it worked perfectly. No C adapter needed! thanks so much!