Wiring help: Taystat 540 to Honeywell RTH9580WF

Old 10-26-13, 10:55 AM
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Wiring help: Taystat 540 to Honeywell RTH9580WF

I have an issue wiring my new Honeywell wifi RTH9580WF thermostat from my old Taystat 540. I have a heat pump. Honeywell says I need a C wire, which I do not have. Here is what I have for wires hooked up to my Taystat 540, and here is what Honeywell has on new thermostat:

Taystat: G, B, R, Y, W, X2, O
Honeywell: C, K, Rc, R, W-O/B, Y, G, W2-AUX/E, Y2, L.

Honeywell also has a jumper between R and Rc.

How do I hook up my new thermostat? What wires go to what on new Honeywell? Thanks so much!
Old 10-26-13, 01:27 PM
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Old = New
G = G
B = C
R = RC (leave jumper in place)
Y = Y1
W & X2= AUX/E
O = O/B

Configure for heat pump with Aux heat.
Configure the O/B terminal to O (reversing valve energized for cooling)
Old 09-06-14, 03:47 PM
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Thanks a lot Houston204 for posting this! Worked perfectly with my Trane heat pump and saved me a Saturday morning crawl space dive to verify the wiring on my air handler!

(Honeywell 9000 uses same wiring layout.)

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