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tacdawg13
Apr 24, 2007, 07:23 PM
I'm attempting to replace my old manual thermostat on a 2 stage heat pump with a Honeywell RTH7400 programmable unit. I'm having trouble matching up the wiring. I have:

W2
R
B
Y
G
X

The Honeywell thermostat has receptacles for the following:

RC
R (jumped to RC)
O/B
Y
G
C
L
E
AUX

I have connected like this and only get the fan; no A/C:
Honeywell Original
RC R (jumped to RC)
R (jumped to RC)
O/B B
Y Y
G G
C X
L
E
AUX W2 (jumped to E)

Where have I gone wrong? Your help is appreciated.

hvac1000
Apr 25, 2007, 05:18 AM
You will need to access your wiring instructions for the new stat and sound out each wire to see exactly where it goes. I would not use any guess work. Damage to heating/AC unit or new thermostat could be done by hooking up the wrong wires. You may also look at the sticky at the beginning of this board. There is some information there on thermostats.