ecobee Smart Si Thermostat 2 Heat-2 Cool with Full Color NON-Touch Screen

I’m glad I waited…and 2-wire installation tip…and note: you need 24vAC, not 24vDC
My old battery-operated programmable thermostat finally kicked the bucket, and stopped doing the one thing it was designed to do — connect (and disconnect) the two wires that tell my boiler to turn on. For a week, I used an alligator clip to short out the wires when I wanted heat, but that got pretty tedious. In years past I’d looked at the Nest and Honeywell wifi thermostats, but they seemed too much trouble — pulling new wires from my basement — for what little I was gaining. I’m sure they’re both fine, but I’m really glad I waited. This ecobee is fantastic. The always-lit display, with outside/inside temp and humidity, is perfect. And once I set it up to connect to my wifi network, I’ve never really needed to touch it again. Programming from either the web or iphone app is simple and logical. Saving on heating bills is all about TWEAKING, and adjusting for what your life is actually like, and the ecobee allows you to adjust schedules and temperatures easily. I work from home, so the usual “9 to 5 I’m not home” logic doesn’t apply. Right now, as I write, I’m feeling a little chilly. I pull out my iphone, slide the temperature up a few degrees, and that’s it. The change I made isn’t permanent — after 4 hours, the ecobee will return to schedule. This is the kind of logic that forgetful humans need. I’m amazed that we could actually use so many fine adjustments to such a simple idea — shorting a wire to control temperature — but we can — all in the name of comfort and saving energy.My ONE complaint — it took me quite awhile to guess how to wire this thing. Apparently the vast majority of houses in the US are still using two-wire thermostats, so I’m surprised there’s not more attention paid to helping us poor slobs out. The install guide covers many complicated situations, and seems to assume everyone has heaters, fans, central air, and two stage this and heat pump that. I have a boiler — and a decent, recent, Utica condensing boiler, not some old behemoth — that simply needs two wires shorted in order to turn on. It uses 24vac internally, but 1) the 24vac wires don’t run to the outside wiring box, and 2) I definitely don’t want to risk overloading its own transformer and mess up its own internal electronics. I considered buying the wall-wart offered with the ecobee (which I assume would have had better instructions than the ecobee), but I really didn’t want a separate wire running up the wall, and plugged-in things have a habit of getting unplugged and heating is too important to risk that. Actually, I assumed one of the hundred power adapters I had from old electronics — many of them 24v — could be used, but heating equipment seems to require 24v AC (alternating current), and not 24v DC (direct current). So I bought a Honeywell 24vac transformer from a box store for $31, and 50′ of 18/5 thermostat wire. I twisted and taped the new wire to my old (cloth covered) 2-conductor wire, and used it to pull the new wire into the basement. The 24vac transformer got its own electrical outlet box — any junction of 120v wires needs to be in its own box to reduce the chance of sparks starting a fire — and as always, TAPED the twist caps to their wires with electrical tape, so that even if the wires came undone, they wouldn’t be floating around bare. I connected two leads of the 18/5 wire to the wires coming out of my boiler, and two leads to the 24vac transformer, wrote down the colors, and headed upstairs. (There is no polarity to either the boiler wire or the 24vac, as far as I know.) The ecobee install guide showed a typical 2-wire PLUS COMMON install, but nothing to help me out, with my separate transformer and no COMMON. What you read in other reviews is correct — that you connect the 24vac transformer wires to C and Rh (doesn’t matter which to which). What nobody seems to point out is that, for a 2-wire boiler, you ALSO connect one boiler wire (they call it R) to Rh, and the other (they call it W, but as far as I can tell it doesn’t matter which one it is) to W/OB. So you have two wires going into Rh, and — fingers crossed — the thing worked! Needless to say, I could have gotten away with only 3 wires, if I’d connected one of the transformer outputs to one of the boiler wires in the basement. It’s worked for a couple days now, and hasn’t gotten fried, so I’m hopeful. I may not have done this correctly — I realize there may be power to one or both of the boiler wires when the boiler is turned on…? and would that matter? — so don’t quote me on this install method. Maybe best to call the company, as they recommend, for advice.Coolest feature I hope I never have to see in operation — the ecobee will email you if your house temp falls below or above a certain level, giving you time to fix things before your pipes freeze, or the boiler runs wild. (Or, I assume, if there’s a fire…). Other favorite feature is that relative humidity is displayed, both onscreen and on the web/apps. Someday I do hope to separate my house into zones, and I don’t believe this ecobee allows for remote sensors or zones, but I figured by the time I get around to needing it, there’ll be other improvements in thermostat design I’ll want. All in all, this is the best possible combination of features and price. Because of the extra fine tuning I can do — with EASE, that’s the important part — I believe I’ll save 10-20% on my heating, which (with an old house near Boston) means the thermostat will pay for itself in 2 or 3 months.

This is the most economical choice if you have a newer Modine or Reznor, want wifi control, and to take advantage of that sweet sweet c wire without spending big money.Installs easily and works with my ecobee 3 lite in the official app and existing home assistant integration.

Installed this in my 2010 Keystone Retreat Park Model RV, and although it works fantastic for the Air conditioning in the summer and I can adjust it before I head up to my campsite the heat does not work as good, as soon as I select heat the Ecobee reboots over and over. To fix the reboot issue I had to disconnect the heat wire, I found that the voltage drop is significant when calling for heat and that I would need a power booster to make heat work. Not an issue with the Ecobee more with my wiring. I installed this myself I would recommend a professional HVAC tech install for you into an RV, I have another Ecobee at home which I installed myself with no issues at all, works fantastic.

Replaced my 5 year old thermostat with this new one because it would no longer conect to server. Took it out of the box and plugged into existing pin connections and it works great.