Heat Pump Thermostat Wiring!! Why is it like this? Picture inside

[aub141]

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:
http://i45.tinypic.com/23jo40p.jpg

[dsprice]

We don't give DIY advice here. Too many unknowns and we wouldn't want to be responsible for inadvertently causing any damage to you, your system, or your home.

[motoguy128]

Only thing I'd add, is DO NOT RELY ON WIRE COLORS, until you've verified where they are landed. While there are some wire color conventions, it's not a requirment. The fucniton of wire colors primarily is to make life easier for an installer and so that you know a red wire 100' away is still the same red wire on the other end.

IF you don't know what "E" is and what every terminal does, save yourself the headache and call in a pro. A single mistake will cost you 1X - 10X more than what you'd pay to have it installed professionally. Plus they can perform a regular check-up on the whole system while they are there.

[zibby]

If you pay for travel expense, then I'll come over and fix it.

[vstech]

the installation instructions for your digital thermostat are very explicit. if they do not explain the enumeration of the old thermostat... you have the wrong thermostat.

[kamersoutdoor]

If you pay for travel expense, then I'll come over and fix it.

Didn't know that "pimping" ourselves to the public was fashionable in AOP!

sent from my Samsung Galaxy Note

[vstech]

Didn't know that "pimping" ourselves to the public was fashionable in AOP!

sent from my Samsung Galaxy Note

I thought that was a perk to AOP membership!

[kamersoutdoor]

I thought that was a perk to AOP membership!

I thought the "perk", was educating the general populace!
Building a higher more reputable name for "our" industry. Saving face, sort of speak!

sent from my Samsung Galaxy Note

[buzhall]

The jumper is in there cause e and w are for electric heat .e being emergency heat and w or w2 being second stage.the idea is to have a portion of the electric heaters to work as second stage heat and all heaters work when you switch to emergency heat.the way it is wired all heaters operate with second stage. If you wanna go buy your own t-stat go ahead but don't monkey with I t call a pro and let them install it it will save you a lot of headache and problems.I get at least 2 calls a month where someone has change out the stat there self and nothing will work 30 minutes later the unit is back online and I made easy money and the wife of the macho husband is sayin I told yo u to call someone now it's cost us even more.