I ave a TRANE S9X2 Furnace-2 stage heat and Trane single stage XR 14 ac unit.I wanna move my thermostat and use new wire ...will 18 /6 do the job?


3 Answers 3


18/5 and 18/7 are the most common at the big box stores here. If you are already set on running new wire, more conductors is always better. You can always leave one or two unused, but it's very difficult to add more. :)

With 2-stage heat and single cool, you are already at 6 conductors.

I'd go with 18/7.


Let`s count,

R+C+G+Y+W, that is 5 wires for single stage cooling and heating with no spares.

If you have anything more like dual stage heating (W2) and/or cooling (Y2), or you have humidifier or dehumidifier, you will need more wires.

Recommend would be 18/7

for your situation, since you have 2 stage heating you need R,C,G,Y,W1,W2 = 6 wires cable and not spares left for anything else.


Use a single multi conductor cable without splices that goes from the furnace to the thermostat. You can use any reasonable wire, if there are extra conductors just ignore them. If there are not enough conductors get a different cable. Most Important is first take pictures of each end and what wire is connected to what noting colors. Then make a sketch showing the ends connected together as it is currently wired. Now take that sketch and mark the new wire color on the sketch using a different colored pen.

At this point you have wiring map as to how it will need to be wired. Run the wire from the stat to the furnace or other direction it does not matter. At this point it is important that power be off until you finished removing the stat and moving it to the new location. If you have not had a lot of experience at this connect one color at each end and check your diagram to be sure it is correct. Continue until all wires are connected. At this point you can turn the power on and it should work flawless if it worked that way before moving it.

Take your time and Take pictures.

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