Hi. Let me first explain that I do not know very much about HVAC. I have an old honeywell thermostat that I could not find any info about. I've searched through posts and looked at diagrams, but can't seem to figure out how to hook this one up. I think I might have the wrong thermostat. I have a yellow and an orage, but on the new one. They are going to the same terminal. I don't know Im uploading pictures of old thermo, new one and the new one's connections.

Here are links to the pictures. They're pretty hi res, so upload might be a little slow, sorry about that.

Old thermo
New Thermo
New Thermo Connections

Thanks in advance.

BTW, the black wire was connected to the X terminal in the picture, sorry abou thtat I had it disconnected when I took the shot.

I'm assuming that
Black wire = Common (Ground)
Red wire = 24 volt
Yellow and Orange = something to do with the A/C
Green = Fan
Blue and Brown = Heat

I think I don't have the right thermostat and maybe I have a 2 stage heat pump.
Thermostat says it's only for single stage with auxiliary heat.
Any help would be appreciated

Yellow and orange should not be on same terminal... what kind of heatpump do you have? You would not have a two stage heatpump based on your old tstat. Lookes like y1 equals yellow. And the y/o is for orange. There should be a switch to be for one stage according to the tag inside new tstat.

There is a chance your new tstat is wrong for your unit...

It says Nordyne on it. Seems to be too many wires for the new thermostat. I'm thinking that it's not compatible.

Here is a pic of the connections at the heat pump. Hope this helps. I couldn't find any info or manual for it, so I'm hoping someone has some experience with this model.

The top group of wires is coming from the old thermostat right now.

There is so much rust a corrosion on that last pic of the terminals I am surprised it works at all. A small wire brush and a pocket knife will do a world of wonders for those connections. It is only a 24 volt system so it is sensitive to bad connections.

I might have a old change over wiring diagram for that thermostat or something close to it. It is on my other computer so I will try and post it later tonight.

Thanks, I'll be sure to clean up those connections.

This may help you. It tells what some different terminals do on older units.