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I will be happy to help. You may have let wires touch or connected on in wrong place and blew a small 3 amp fuse on furnace board. Tell me first about the wiring.What wires you had to what terminals on old and where you put on new.
The two most common reasons for your current situation are:1.You did not turn power off at furnace and while replacing wires allowed the R power wire and the C Common wire touch and spark, blowing the fuse on furnace board or2.If your old thermostat had a B terminal for common and you put that wire on B terminal of new thermostat(New thermostats use C for common and B for a heat pump reversing valve).So if you put the old B to the new B and call for heat , this would again create a dead short and blow the little fuse in furnace.Below are images of the fuse I am referring to located on control board in blower compartment.If you simply forgot to turn off power and let the wires touch , blowing the fuse, all you should have to do is replace the fuse and you should be good .If you connected an old B to new B, you will need to mobe that wire to C, then replace fuse and you should be good.https://i.imgur.com/UxPpnn4.pnghttps://i.imgur.com/kYe4Epz.png
Let me know and we will go from here.
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