Ever since I lived in Fayetteville Arkansas I've wanted a programmable thermostat. I know they save money.

Everyone always said to me you should leave the AC on while you're gone, because you'll use more energy cooling a hot house than keeping a cool house. This never made any damned sense to me, because I knew a modern HVAC (Heating Ventilation and Air Conditioning) system could cool a house in less than an hour, and I was gone for eight hours at work.

So one year I listened to everybody else and left the AC on while nobody was at home. I ended up with huge electric bills... something like $120 a month at one point (Arkansas can have weeks of 100+ degree temps, and this was an older house). The next year I set up box fans in the upper-story windows, and turned the damned thing off when I left. The bills never exceeded $85, and were usually around $75.

But it did mean I had to sit in a hot house for an hour, and sometimes I'd forget and leave it on all day anyway. There was bound to be a better way. Enter the programmable thermostat, which is designed to turn off around the time you leave, and turn back on an hour before you come home. Now that I have my own house, I decided it was time I actually went and got one.

"Have you ever installed a thermostat?" Ellen asked me in that 'oh-god-he's-gonna-blow-the-house-up' voice she uses when I get a project in my head.

"No, but I never installed a kitchen faucet before, and that turned out OK didn't it?"

"It took three hours and four trips to Home Depot, and you still got water all over the place."

"But you got your fancy faucet, dincha dear?" I said with a smirk.

"Yes, but..."

"Look, my dad used to work on air conditioning systems in Houston (which was true), I'll just wait until he comes out to visit us before I put it in (which wasn't), mmkay?"

"Swear ta gwod," she said... she always gets New York on me when she Lays Down the Law, "if you goiys burn down my house, I'll kick ya 'til ya dead, unduhstand?"

"Your house?"

"DEAD!"

I picked out a Lux 9000 Series Smart Temp Electronic Thermostat, a 7-day programmable model recommended as a "Best Buy" by Consumer Reports. Found it, after some searching, at Home Depot for $54. "It's a bargain!" I exclaimed to Ellen, who was giving me her patented Lizard Blink... a diamond-hard stare she shares with most alligators and crocodiles (she lacks only the 3rd eyelid. I think.) "The next one they recommended cost $180!" Think fast... think fast... "It's almost like it was on sale."

Yeah, it was lame, but after proving my love by sitting through the "Sahara... Sandy Beach... Sahara... Sandy Beach... Sahara... Sandy Beach..." routine looking at paint chips, I was permitted to make the purchase.

Now, I really hadn't installed anything like this before, but how hard could it be? The instructions were pretty clear, and I only found one message on the Internet complaining how a guy couldn't stop breakers from throwing in his house after he'd installed one. Piece o' cake!

So I waited until Saturday, when Ellen would be gone all day, to tinker with my new toy.

The house came with a standard rectangular thermostat. If you don't have one in your own house I'm sure you've seen them. They're completely mechanical, as far as I can tell anyway, with a bimetallic spring and two mercury switches to turn the AC (or heat) on and off.

I knew how to take the faceplate off. I'd learned how years ago when I made a bet with my brother that the marker inside was actually a thermometer. How to prove it? Nine year old me: "Well, microwaves heat things up fast, right?" Seven year old Jeff, sensing an opportunity to get me in trouble: "Uh, sure! Sure! Let's try that before mom and dad wake up!"

Well, how were we to know the blasted thing was full of metal? It did make a lot of pretty sparks! But I digress...

Anyway, I didn't know how to get the rest of it apart. This is where patience and a little detective work, along with a bit of judicious prying and swearing, paid off. I pretty quickly had the thing down to its mounting screws and connecting wires.

"Self", I said to myself, "I bet there's a good bit of voltage in there, whatcha think?"

"Well, not a whole lot... the instructions say 24 volts... that can't be too bad can it?"

At this point I got one of those dramatic voice-over flashbacks, you know, the kind where the guy looks up at the corner of the screen and a disembodied voice rings out from the past?

Mine said "DEAD!"

So I trooped downstairs like a good boy and opened the breaker box. There were breakers labeled AC, but none labeled THERMOSTAT. Well, I figured if the AC breaker is thrown I can't damage that, so I turned it to OFF and headed back.

It was only a short while later I found out that 24 volts is just enough to give you that "not-so-safe" feeling when it tingles your fingertips like a few passes with 80-grit sandpaper. Back downstairs I went. Hmm... lots of breakers labeled "lights"... it'll probably be one of those. But to find out which one I gotta do the sandpaper-on-fingertips thing a couple of times. So I did the manly, subtle thing.

I threw the main breaker.

The now safely "cold" thermostat (in a rapidly warming house) was pretty easy to remove. And you know what? It really isn't that hard to hook up. Or rather, mine wasn't that hard to hook up. All the wires are colored, and the first letter of the color is stamped on the screw you tighten it down on. I moved very slowly so it took a little longer than it probably had to, but in about 30 minutes I had that bad boy hooked up.

Then my next stumbling block rose up and stubbed my project's toe... batteries. The thermostat runs on AA batteries, which I knew I saw somewhere, but couldn't find. I went through every drawer and every cabinet, no luck. Ellen had the car, so I couldn't just go to the store to get some. I was not going to get this close and then be stuck with no AC for the next six hours. Luckily, while tearing through boxes I did come across an... um... "personal relaxation device" (that's what it said in the catalog she ordered it from anyway). That ran on AA batteries.

So back downstairs I went, plugged the batteries in, and put the whole thing together. I went over to the breaker box, said a little prayer, and threw the breaker on (with my eyes closed).

Seconds passed.

The A/C kicked on.

The breaker did not throw! Woo-hoo!

After a few minutes of programming I had myself a fully-functional hi-tech thermostat of my very own!

So if you're thinking about something like this, and have an HVAC system that's relatively new (or even if you don't... the instructions cover a bunch of different configurations), I highly recommend it. It really wasn't that difficult.

Now I just have to find another set of AA's before she gets home...