7 wires and installing Honeywell RTH6450

Old 04-09-15, 05:29 AM
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7 wires and installing Honeywell RTH6450

I recently had an upstairs thermostat go out, display just stopped working, so I bought a new one. I uploaded a picture of what I started with, I've followed the instruction manual, I've searched all over the net and nothing has yet to fix it. Its taken me about 2 days so far to achieve nothing. Please Help!!!!Name:  thermo.jpg
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Old 04-09-15, 08:31 AM
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Looks like a heat pump with back up electrical heating coils.
I only see six wires. Did I miss one ?

These colors should match with the same letters on your new stat.
C---> blue
G---> green
R---> red
O---> orange
Y---> yellow
W2---> white with jumper to E

You must configure your new stat for your system type.
1 ---> 5
2 ---> 0
3---> 1
5 ---> 5

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Old 04-09-15, 12:05 PM
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There is a brown wire in there as well, that would be the 7th but it wasn't hooked up or anything, just wanted to make sure it didn't need to go on the new one.
Old 04-09-15, 12:14 PM
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I don't feel entirely to smart right now, I actually am pretty mind blown. I'm a helicopter mechanic and house stuff always seems to get the best of me......anyways this is the plate and terminals that I have I don't have a "C" terminal and w2 is on the same terminal as E. I think this is why I'm so confused.Name:  therm.jpg
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Old 04-09-15, 09:01 PM
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Connect white to Aux/E.
Connect orange to O/B.
Tape off the blue wire.

Orange went to an O/B terminal on the old stat.
Do you know if it was configured to be O or B?
Rheem, Ruud and Weatherking use B. Almost every other manufacture uses O.

Has anyone been working near your furnace recently?
A blank stat is often caused by a workman turning off the wrong light switch when leaving an attic or basement.

Another common cause for a blank stat is a backed up AC drain tripping a float switch in a secondary pan under the cooling coil.

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