NestThermostat E Programmable Smart Thermostat for Home, App Controlled via Wifi, Programmable, Compatible with Alexa and Google Assistant, Frosted White Color (T4002ES)

I bought this on recommendation from HVAC tech for my older heater system which uses 24 volts. He came over and made sure the wiring was correct, he had to add two additional wires since old thermostat only used twoFirst one did not work out of the box. Scheduled a return and ordered a second unit and it works great. Very happy with the Nest thermostats. This is my third one. I have one at my home and now my mother in laws for this oneI added one to a mountain cabin as the previous electronic model would reset to a high temp after power outage. Not great during the winter when we are not there. Want to keep it from freezing but not 70 degrees if no one is around.Also I can preheat the cabin to be warm before we arrive.

If you have a 2-wire system that's heat or cool only, this thermostat will work for you. It will work a system is a millivolt or 24V system.For a millivolt furnace like the Williams Top-Vent Gravity Wall Furnace, you'll need a 24V transformer to act a C wire to provide power to the thermostat. You can search for transformers that work with Nest on Amazon. One such example is the Viivria AC 24 Volt Transformer. Once you have your transformer,1. Connect the one end of the transformer wire and the red R-wire for your heat/cool to the 'R' terminal.2. Connect the other end of the transformer to the 'C' terminal.3. Connect your other wire (likely white) to the 'W' terminal.4. Put the thermostat back on its base.4. Plug in the transformer.This configuration should keep your thermostat powered. I've had this configuration for 2 months and it works well.

I hate it. It's terrible.1st Why is the temperature gage that shows you the temp in the room, super tiny? You have to lean your face a foot from the controller to see it. The big number, that you can see from across the room, that's the setting. Well I know my setting. I'm the one who set it. What I don't know is the temperature in the room. That should be the big number. Unreal lack or logic.2st But wait it's worse. That fuzzy image that you see, it's the exact same in real life. Why? It makes me feel like I need glasses. Why isn't' it clear and crisp? Unreal lack of common sense and logic.3rd The settings, the programing is so complicated you need a PHD in Computer Science to figure it out. And if you don't do it in the exact correct sequence, it just resets on it's own.4th But wait it's worse. It completely ignores your settings, anyway. If you set it to 70 but you're working the next room and it doesn't sense you walking by, it will completely ignore the setting and let the temperature rise to 80. So you have to walk by it every half hour or it will not cool your home, and there is no way to change that.5th If you download the app, it then wants all your personal information, NOT for your benefit but to sell your data online. It pretends in the terms of service not to do that, with confusing legal lingo, but that's what it does. That's how they make their money. Just another data collecting scheme.Stay away from it.

Its great fast shipping very easy install well described and programmable great cycles turns to eco mode when not home saves energy A+++++ highly recommend

Easy to use. Love how it lights up when near by. Nice big numbers, easy to read

Followed the install instructions and it would just not turn on or recognize my wifi. I saw a usb-c charging port and thought I’d give it a try. After a few hours, it “woke up” and was charged up and ready to go. If the instructions were more intuitive I would have given it 5 stars. But I wasted 2 hours trying to troubleshoot then another couple hours waiting for it to charge.My tip: if you buy it check if it has a charge before you start installing

We love it work really good we have it for 6 months already

Spent 3 days thinking I did something wrong. I connected this to a 2 wire (white and Red) boiler/radiators. Day 1 connected it and got blank screen...assumed I needed the transformer to ad power (C wire and R2). While I waited I left it connected to the boiler...by my surprise the E thermostat woke up 2 days later...so I connected a usb to manually charge it. 1. Couldn't connect to wifi nore the Nest app I already had for my Heat pump. Omce the transformer came in I connected that..factory reset the thermostat and still couldn't connect to wifi or app...after watching many videos on how simple it should be to connect....I ordered another thermostat....amd it literally took 15 min to install and connect. This was sold and shipped by 3rd party, but was super easy to return and refund within the same day...I was just surprised you could buy a new sealed Nest with iasues. Im writing a review of the 2nd one i bought next.