This site appears helpful, but I didn't see my situation, and I tried the Honeywell wiring wizard but it doesn't include my model.
I currently have a White Rodgers (9510E7) rectangular thermostat and I am trying to replace with Honeywell 5-2 Day Programmable RTH230B.

Currently there are 8 wires coming out of the wall
Blue- not connected to anything
Black- not connected to anything
Red- R
Brown- C
Yellow- Y
White- W2
Green-G
Pink- O

The new thermostat only has room for 5 wires. Some are straight forward, but others are confusing. The outlets are:
Rh- Heating Power
Rc- Cooling Power
W- Heating Signal
Y- Cooling Signal
G- Fan
*Jumper wire between Rh and Rc.

Can someone please tell me what wires connect to the Rh,Rc,W,Y,G Honeywell outlets and which are not used (and possibly why not used). Thanks in advance!

I believe you have the incorrect thermostat. You need one for a heat pump and the one you bought is for standard heat and cool.

See introduction on this manual

http://customer.honeywell.com/techli...0s/69-1800.pdf

Thanks HVAC for your quick response to my question! I have central heat and air, and I believe I do have a heat pump. I will go back to the store and exchange. Any suggestions on a particular model or brand that will make my life easiest with this particular switch?
Thanks also MarkwithaK for agreeing as well. This site rocks!

It is a very common mistake. Some homeowners do not even know that they have a heat pump. As far as what t-stat you should buy, I'm partial to Honeywell but that's just me. I stock the Vision Pro series on my truck but again, that's just the preference of my boss. We used to stock a WR. As to what model it all depends on what bells and whistles you want. As long as it is heat pump compatible you'll be OK.

After an answer on this site I purchased a new thermostat today capable of central heat/cool and also for a heat pump. It is the Honeywell RTH6400. I currently have a White Rodgers (9510E7) rectangular thermostat. I am still having problems figuring which wires go where.

Currently there are 8 wires coming out of the wall
Blue- not connected to anything
Black- not connected to anything
Red- R
Brown- C
Yellow- Y
White- W2
Green-G
Pink- O

The new thermostat only has room for 5 wires (6 counting the "NOT USED" outlet). The outlets are:
G
W O/B
NOT USED
Y
R
Rc
*Jumper wire between Rh and Rc.

Some are obvious:
G-G
Y-Y
R-R
Rc-None
The instruction manual says not to connect C, just wrap with electric tape.

But I am left with O and W2. The instructions say to connect O to the W O/B outlet. If this is the case, then where do I connect the W2 wire? And if I were to connect eh W2 wire to the W O/B, then where do I connect the O wire.

Please help! Thanks in advance.

See page 11 below

http://customer.honeywell.com/techli.../69-2210EF.pdf

The thermostat you have will only do one stage of heat. Looks like you will have to go back for a different one again.

You need a thermostat that has one stage of cooling and two stages of heating capability.

The electric furnace/furnace and the outdoor heat pump are controlled by different sections of the thermostat. Hense the necessity of two stages of heat.

The thermostat you have now only can do one stage of heat

Regular furnace/electric heat

OR a heat pump but not both.

Sorry.

PS when you get the correct thermostat your wires will fit OK. Post back if you do not understand or need further help.

Thanks HVAC. This is all new to me. I bought the most expensive honeywell Lowe's had, so I assumed it would do everything. With all the info you gave me finding the correct thermostat shouldn't be that difficult. Thanks again, and hopefully this will be my last post... but maybe not, HA!

You can do it. Third time is the charm!

Thanks for the help, I got the new on installed, and it seems to work. I did fill out the wiring wizard at honeywell to double check myself, and they emailed me the following answer. Why do I need to install a humper between AUX and E? Currently I have it wired with W2 into AUX and no jumper. I have not yet tested the heat, but the A/C works fine. If I should install this jumper then where do I get a jumper? OR can I use a certain gauge wire?

Current ThermostatRTH7400D\RTH7500D
R=R (Please leave the factory installed jumper between R and Rc intact)
Y=Y
G=G
W2=AUX (Please install a jumper between AUX and E or extend the same wire to E)
O=O\B
C=C

Thanks again!!

Standard thermostat wire will work as a jumper. I suggest you try the heat and if it does not function as intended then add the jumper. I believe the request of the jumper from Honeywell to be valid but you never know.