Can someone give me the proper connections for my thermostat? The a/c / heat pump is a Rudd model (-AKA, -ALB, -AMB).

There are four wires coming from the wall (red, white, green, yellow).

They were connected to the old White Rodgers model 1F80-361 as follows:

G - green
Y - yellow
W - white
RC - red
RC to RH jumpered

The new Honeywell RTH3100C has the following connections available:

E, Aux, Y, G, O, L, R, B, C

 

With only four wires at the stat it's not a heat pump.

 

There is a fifth blue wire coming from the wall, but it wasn't hooked up to the old thermostat.

 

The blue wire is spare wire which you might need for a new stat. The stat you bought is for a heat pump. I would take it back and get an RTH 6000 or higher.

 

Is this your thermostat?

https://customer.honeywell.com/resou.../69-1889EF.pdf

 

Yes it is. I already have it hooked up and running the a/c. I tried to run the heat, but it's either not heating, or it's too warm to verify function. It was 78 deg in the unit here in Florida. I set it to 81, but it never got warmer.

Right now, this is the way I have it hooked up:

Y - yellow wire
G - green wire
R - red wire
Aux - white wire
E and Aux jumpered
blue wire left unconnected

I ran it with and without the E to Aux jumpered. It seemed to make no difference.

I'll admit I don't know if the unit has a heat pump. I don't know how heat is provided.

 

You need to connect the blue wire to C terminal on the stat. We will need the model number on the furnace to tell you where to connect the blue wire at the furnace.

 

I don't believe anyone has a conventional furnace in South Florida. Certainly no gas or oil hooked up to our condominium complex.

 

Fixed! I got the proper thermostat - a Pro1 T701 model. Hooking it up was straightforward. I now have heat as well as a/c. Thanks for the help.