Help with wiring on thermostat installation

Old 05-19-14, 08:53 PM
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Help with wiring on thermostat installation

I've just moved into my new home and wanted to replace the current non-programmable thermostat with the programmable one I have had for a couple years now. Here is some of the information about my home that I'm aware of:

Electric (No Gas)
Heat Pump

Old Thermostat: Honeywell Heat Pump Thermostat, T841A 1597 ;Two heat/one cool; manual changeover.
(Link to wiring PDF for multiple Honeywell:

New Thermostat: Hunter 44277
(Link to wiring PFD:

There were 8 wires on the old Honeywell:

R = red
Y = yellow
G = green
O = orange
W2 = white
X = blue
W3 = black
E = brown/greyish
("L" and "B" terminals were unused)

I can't figure out what goes where... When I was hooking it up, I had two leftover wires. I was trying to use the "Multi-Stage Heat Pump" wiring chart from the Hunter PDF, very bottom right diagram. My assumption was:

Wire Color

R = Power
R = Heat 24V Supply

Y = Compressor
Y = Compressor Contact

G = Fan
G = Fan Relay

L = System Monitor*

O = C/O Valve Cool
O = Cool Relay Valve

W2 = Aux Heat
B = Auxiliary Heat

Aux/E = Second-Stage Cool

X = Common
C = Common

If those are correct, then I'm missing the Black W3 wire (Unless "Multiple Aux Heat Loads" W3 goes to Aux/E "Second Stage Cool") and then where would Brown/Greyish Wire E "Emergency Heat" go? Any help would be greatly appreciated!
Old 05-20-14, 05:29 PM
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old = wire = new
R = red = R
Y = yellow = Y
G = green = G
O = orange = O
W2 = white= Aux/E
X = blue =C
W3 = black =tape off
E = brown/greyish = Aux/E along with white.

Set your thermostat switches for HP and Elec.
Old 05-21-14, 07:49 AM
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Just hooked it up and it seems fine! Thanks a bunch!!!!!

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