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General Forums => General => Topic started by: mhasselb on November 13, 2022, 02:34:10 PM

Title: Replacing Trane XL802 thermostat with Honeywell RTH9585WF
Post by: mhasselb on November 13, 2022, 02:34:10 PM
I need to replace my Trane XL802 thermostat with the new Honeywell RTH9585WF I purchased. I can't find a wiring diagram that is the same as mine therefore I can't map the wires to the right place on the new thermostat. I've attached a photo of my current device (and wiring) and pic of the new wiring panel. Can anyone just map the 9 wires from my current set up to the right places on the new thermostat? Thanks in advance for anyone's help!
Title: Re: Replacing Trane XL802 thermostat with Honeywell RTH9585WF
Post by: Admin on November 13, 2022, 03:09:05 PM
S1 and S2 are likely wired to a proprietary outdoor sensor you can no longer use with the new thermostat.  The new thermostat WIFI should gather the outdoor temperature, so you can eliminate those 2 wires.  You likely need to use one of them as your C wire now.  Disconnect it from the sensor and connect it to the C terminal in the furnace and then the other end to the C terminal on the thermostat.

X2 is the AUX wire (AUX/E) and B is the reversing valve (O/B).  There will be a thermostat setting to change the reversing valve to energize on heating or cooling.  You may also have to adjust the thermostat and cut off temperature if you're running a dual fuel heat pump system.  The other wires should just connect the same. R, W1, W2, G, Y.