I have recently acquired a Hunter digital thermastate model 42999B to replace the old one and I am having trouble figuring out how to wire this guy.
The old one had the following wires that were labeled and colored as noted:
White = W2
Green = G
Red = R
Orange = O
Blue = X
Yellow = Y

The new thermastat has the following connections:
Rc/O
Rh/B
Y
W
G

I have no idea how to connect this with what I am looking at here and was hoping someone could give me some direction.
Thanks!
Pat

I may or may not be able help you figure it out. If it is a heat pump system*, you need to figure out what signals it needs to switch back and forth between heating and cooling. Otherwise it is fairly straight forward. Usually you jumper red to both RC and RH. Yellow goes to Y, white to W, and green to G. I think the orange is usually part of switching the heat pump modes. The blue wire to the X may have been more heat pump switching, or a common to allow the thermostat to draw power from the transformer. Did you get instructions with the thermostat, and do they say anything about connecting it up for a heat pump? You may have to activate and set the mode or jumpers to use it with a heat pump. In the heat pump mode, you may connect the orange wire to the RC/O terminal rather than jumper it to RH.

*Heat pump, a system that uses the same outside compressor to both heat and cool the house through a system of reversing valves and coils.

Labman,
Thanks for the quick reply. I am really unsure about the whole heat pump thing. I just moved into this house and just wanted an easier to use/read thermastat so I tried this Hunter one. It must be a heat pump as you had stated.
I wired the white to the W, yellow to Y, Green to G, Red to Rh. Then I jumpered the Rh to the Rc. I have it set to turn on to cool right now as it's hot in my house, and the unit did come on as it should only rather than blowing cool air out, it was blowing hot air.
With the orange wire connected to the Rc nothing happens, same as if I connect the blue wire to the Rc.
The instructions did talk about using it with a heat pump. They have only a 5 wire configuration (though I have all 6 of those wires coming out of my wall). IT says the following:
Fan relay to G
Heat relay or valve to W
Cool contactor to Y
Heat 24V supply to Rh
Cool 24v Supply to Rc.
Any ideas from here? How could I go about finding more about what my actual heating/air unit is?
Thanks so much,
Pat

If the unit outside with the fan runs and the vents in the house are giving out heat, chances are it is a heat pump in heat mode. A lack of a propane or oil tank or a gas bill is another strong factor. Did you buy this place? Do you have the description from the Realtor? They always give the type of heating system.

Track down where the thermostat wires go. Likely the same as the vent ducts, the attic, crawl space or a closet. Wherever, follow the sound of the blower and likely you will find the other end of the wires. Post back what all the thermostat wires are connected to. W, R, Y, etc. if anything. If any of the unit looks like a panel slides open, open it. If you see filters, look and see if they are dirty. If so, clean or replace them. That needs to be done several times a year. Also look for any instructions for the system.

There should be a pair of small wires running out to the outside unit. One will be connected to a transformer inside. The other may be connected to the white or yellow wire. Post back what you find. What a fun New Year's Eve.

Hey Labman, sorry I never got back to you. I called the company, Hunter Fan, and they told me that the thermastat I had was incompatible with my unit. So you were right when you said you may not be able to help. Thank you so much for your help though I do appreciate it.