Hi everyone. If anyone can help me I'd be sooo much thankful, appreciative. I have a Trane xl12 heat/cooling unit. A Trane tweo24p 130b0 air handler. And the thermostat is a trane T8411R. All of the equipment is about 8 or 9 years old maybe. Yesterday I lost the display on my thermostat screen and called 800 #. They asked a few questions, said the display couldnt be fixed, to go get this other new one from lowes or home depot. Now, the thermostat would still heat and cool, I just had no way to see what the temp setting or anything was to control it right. So I go get the thermostat they said to get. Install it exactly right, very careful, stickers on each wire, one at a time, just very meticulous. Well, after I turn on the breaker nothing works. I try a few things, nothing, so I call 800 #. They ask a few questions again, get letters off the wires and so on, then say I installed the wrong thermostat, to go get this other model and that one will work with my system. Well I only installed the one THEY said to install. So I'm screwed I figure while he's saying I probably blew a transformer or fuse at air handler, the breaker or somewhere else. All this in an accent I could barely make out! I was livid and couldnt understand what they werte saying to me. So anyway, thats where I'm at and if anyone knows or has any idea what to do, I will be forever indebted to you all to say the least. Thanks a lot!, Marc. (the wrong thermostat was model #RTHL111B and the correct one that goes in there is model # RTH3100C) Thanks again!!