# How to wire up this thermostat



## timbo59 (Mar 16, 2010)

I recently bought two Honeywell thermostats to replace the old thermostat we inherited when we bought our present home a year or so ago.

The first Honeywell model we bought was a more expensive unit, but it turns out it wasn't suitable for our A/C - heating system, so a cheaper version was recommended that would do the job (RTH2410B). But the more I look at it the more I have a hard time trying to figure out where to put the last remaining wires. Because I am moving the thermostat location to another area, I had to run a new A/C cable out, and I copied the connections where the old cable was attached with wire nuts exactly to make sure I didn't screw up. I don't know how an AC is normally wired up, but ours has five main wires coming out of the blower and attaching to two AC cables with seven strands each (the orange isn't used), one running up into the roof and the other going to the thermostat. If any of this makes sense to anyone, I'll outline how the wires are set up.

A/C wires /Cable to roof / Cable to Thermostat
Black.....................................Green
Brown............Brown................Brown
Red.......................................Red
Purple............Red
Black.....................................White
...................Yellow................Yellow
....................Blue..................Blue

As per the picture, I attached most of the wires according to the color coding, though in hindsight 'B' could also have stood for Blue instead of Brown.

With what I've written, plus the attached pictures, can anyone figure out how I'm supposed to finish off the wiring?

If anyone can help, I'd certainly appreciate it.


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## beenthere (Oct 11, 2008)

The white wire probably is for your aux heat, so it should probably go to the W/aux of the stat.
Everything else looks ok, from here.


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## gregzoll (Dec 25, 2006)

Go look at the Furnace/Air Handler, and look at the colors as to what terminals they are hooked up there. When unhooking thermostat wires, you always tag with a little piece of tape with what terminal they where on, so that you can hook things up properly. Even having a sheet of paper with the colors/terminals wrote on it helps.


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