Replacing Honeywell T841A1233

Hi there,
I am trying to replace an old Honeywell Thermostat in my Condo with a newer programmable one. The current system (Carrier 40AQ) has a Heatpump with an Emergency Heat option and is is controlled by Honeywell Thermostat T841A1233. The wiring is as follows:

T-Stat Label - Color
W1 Blue
G Green
Y Yellow
O Orange
R Red
X1 Black
W2 White
E Brown

The new Thermostat is a Honeywell RTH7500. I was trying to map it but it appears that I have one more wire than the RTH7500 can accommodate

Old Label - Color - New Label
W1 Blue C ????
G Green G
Y Yellow Y
O Orange O/B
R Red R
X1 Black C ????
W2 White Aux/W2
E Brown E/Y2

Any help is appreciated. Thanks in advance,
Martin

 

Are you sure it's W1 that's the blue is on? I looked at the stat's manual, and I am not seeing W1 listed. You may have to go to the air handler and see where the blue wire is landing at the other end.

Old-------------New
W1 Blue-----?-
G Green---------G
Y Yellow--------Y
O Orange------O/B
R Red----------R/Rc
X1 Black-------C
W2 White------Aux
E Brown-------E

 

Thanks for looking at this. I was out of town for the last days and just got back. I am pretty sure that I got the current labeling correct but I will check again.
Thanks
Martin

 

Hi there, it appears like yesterday that I originally posted here but I guess it has been a year - and I still have the same issue. Talking about procrastination...

Anyway, I finally traced the wires back to the Carrier unit and there, the blue and yellow wires coming from the current thermostat are wired together.

Should it be safe to assume that I can just ignore the existence of the blue wire and just follow Jay's original mapping?

Thanks,
Martin

 

Yes, follow Jay's wiring instructions.
Configure option 170 to 7 (heat pump with aux heat)

 

Great, thanks again. Just did it and it seems to be working like a charm. Not trying out the heat (yet) - it is hot in Atlanta....

Again, I appreciate the help

Martin