Hello,

I purchased a Honeywell rth230b to replace my Honeywell t8411r. When I removed the t8411r I had 6 wires coming out of my wall that were attached to the thermostat. A red, blue, green, white, and 2 yellows. The 2nd yellow is coming from a second set of wires that all have the same color, but the rest are pushed back and were not used. I cannot figure out how to wire this thing up with this extra yellow. I have no idea what it is for. It was attached to the "O" screw on the old thermostat plate. I can't even find out what that "O" was used for on the old thermostat.

Can anyone help?

Do you have a heatpump? Normally the o is the wire going to energize the reversing valve

Hello,

I purchased a Honeywell rth230b to replace my Honeywell t8411r. When I removed the t8411r I had 6 wires coming out of my wall that were attached to the thermostat. A red, blue, green, white, and 2 yellows. The 2nd yellow is coming from a second set of wires that all have the same color, but the rest are pushed back and were not used. I cannot figure out how to wire this thing up with this extra yellow. I have no idea what it is for. It was attached to the "O" screw on the old thermostat plate. I can't even find out what that "O" was used for on the old thermostat.

Can anyone help?

Update:

I got everything working except for the heat. The fan blows and the AC works. I have it hooked up as follows:

Rh - Blue
Rc - Red
W - White
Y - Both Yellows
G - Green

Before I had the blue and red reversed. I was searching around and saw something about the "O" on the old thermostat being for a heat pump? I am assuming this is why my heat isn't working. Is that separate yellow for the heat only? If so, where should I put it?

do you have a heatpump? normally the o is the wire going to energize the reversing valve

Hey, I made that last post before I saw yours. I am assuming I do. I recently bought this house so I am not sure. Is there a way I can check?

Assuming I do have a heat pump, how would I wire it correctly?

Check your install instructions, should it have a jumper from rh to rc?

No, it says for 5-wire installation to remove the jumper.

But, in the instructions it clearly says that this thermostat will not work with a heat pump. My wife thinks that we don't have a heat pump though, since we have central air and have only one unit in the garage that controls both operations.

Does your thermostat have a EM /emergency heat setting? The old tstat?

No, not that I am aware of. I am at a loss here :(