Help me connect my programmable thermostat?

[SidVicious]

Moved recently and the new house had a very chincy thermostat. Picked up a programmable one and would like a little help hooking it up.

The pic below with the wires is what's on the wall now. The second pic is the new thermostat. I thought experimenting with the wires that are not obvious was a bad idea since it's 107* out today.

If someone could tell me which wire goes where- that would be cool. Thanks guys.

[Rockhead261]

The stat you purchased will not work properly. The existing stat is for a heatpump with supplemental (or two stage, or emergency) heat, usually a strip heater or even a burner. See that little sticker on the lower/left corner of the back of the new stat?? The new one will only work for a single stage heatpump and has no provisions for the supplemental.

This is what's on the wall:

G - Fan
C - Common from transformer (usually needed for a clock on the stat, maybe just a junction)
R - 24VAC from transformer
W1 - First stage heat *
Y - Cooling *
O - Changeover valve
W2 - Second stage/supplemental/emergency heat

* W1 and Y being jumpered indicates that the compressor runs for both heat and cooling with O being the determining factor - when O is energized the system runs in A/C.

Though I do not recommend it, you can connect the new thermostat (in heatpump mode) as follows:

OLD - NEW
G - G
R - Rc (leave the Rc-Rh jumper in place)
O - Y/O
W1 - W/B
Y - Y1

C and W2 from the old stat will unused, hence no supplemental heat. The A/C will work normally, but the heat will be crap.

Bring it back and get a two-stage heatpump stat.

[SidVicious]

Does it matter that we really don't use heat much here? The back of the new unit has a switch that says "System type" and can be switched from STD to HP (standard & heat pump, right?)

I found instructions for 2, 3, 4 & 5 wire system set ups, but this house has 6 wires...

Thanks for the help- I appreciate it

[SidVicious]

Also- Should I jumper Y1 to W/B? W1 on the old unit is jumpered to Y, and you instructed W1 to W/B...

[Rockhead261]

Does it matter that we really don't use heat much here?

This is entirely up to you.

The back of the new unit has a switch that says "System type" and can be switched from STD to HP (standard & heat pump, right?)

Right. It should be switched to HP.

I found instructions for 2, 3, 4 & 5 wire system set ups, but this house has 6 wires...

As I said, you have two-stage heat. The thermostat is not equipped to handle it.

Also- Should I jumper Y1 to W/B? W1 on the old unit is jumpered to Y, and you instructed W1 to W/B...

Nope. W1 (1st stage heat) and Y (cooling) both do nothing more than start the compressor. The changeover valve (O) is what tells the system to cool or heat.

Do yourself a favor - go out and get a two-stage heatpump thermostat. I wouldn't use the one you have there, and I know what I'm doing.