I have a 2ton Heat Pump System.
I'm thinking about getting a programmable thermostat(prolly Honeywell 7600D) because the one i have right now sucks. I m confused on the wiring my installer did. Here is the picture. Please help me figure it out.
I understand the C, O, R, G, and Y but I dont understand the E and W2. I do not know what E is, W2 is AUX.
So here is the question. The brown wire goes in E and white goes in W2, BUT why has he connected a blue wire to E to W2???
If Im going to install the new thermostat do I did to do that also?
Here is the picture: