"Nest" thermostat and other fancy thermostats- Do they need special wiring?

Hi all,

I am planning on updating my thermostat some time soon, and I want to get one I can access via my phone, like nest, or some other one.

I am wondering do they need any special wiring, or is whatever is coming out of the wall now (hooked up to a normal digital thermostat) all that is needed, along with a wireless internet.

Also what is the best one, can anyone make suggestions on a good brand etc?

Thanks

-T

 

I use ecobee thermostats with remote censors for the bedrooms. Most all smart thermostats use the same wiring. You need a C wire to provide power to the unit. So basic wiring would be green, red, yellow, white, and blue. Some thermostats come with a power injector adapter if you only have a 4 wire run.

Hope that helps.

 

I installed a Nest a few years ago. Super simple install. If you currently have a working thermostat then it should plug right in. You’re gonna love it!

 

I have a basic Nest thermostat. It comes with very clear directions on how to match to your current wiring. My power company was sending out coupon codes. I'd never go back to a non-smart thermostat.

 

Should wire up the same as any other thermostat, it’s going to run off your wifi to control from app. I have a Honeywell alexa enables thermostat but I heard good things about nest. Mine came with the home.

 

I installed one last year; it was super easy. Our house was built in 1981, so I'm reasonably certain it'll work with whatever you've got too.

 

easy install with the app. step by step. love my Nest.

 

I’ve got an ecobee and also installed one for my parents and a buddy of mine.

The big thing to keep in mind is for most any smart thermostat, you need a C wire for power. My house doesn’t have one, but the ecobee comes with an adapter to to get power to to the thermostat. Nest and most others do not have this adapter so you are SOL without running an additional wire.

I’ve got an older house and the remote sensors are really nice to have.

 

What he said... The C wire is necessary and not in all homes. If you have an older home or more manual thermostats, then you'll need some way to get the power to the unit. If you've currently got a newer powered thermostat like a Honeywell or something, then you're probably good.

I've also got the Ecobee - mine pre-dates the Alexa integration, but I don't use any of those "voice assistants" anyway. I have found that once I set the thing, I rarely touch it (but my wife is constantly over-riding it when she feels cold or hot). Good thing is that if I wake up in the middle of the night and hear it running when it shouldn't, I can reset it back to standard program from my phone. What steered me to the Ecobee was the remote sensors that have both temperature and room occupancy. While there is NO WAY to truly balance out every room in your house unless you have a true multi-zone heating/cooling system, you can set up your system to read and adjust the overall system temperature based on the averages of different remote sensors, determine which sensors are even used in that averaging, and control if those sensors use occupancy detection or not as part of that averaging.

For example:
Our house is two stories plus a basement (currently unconditioned). The upstairs has the two kids' bedrooms and a jack-and-jill bathroom. The main floor has laundry, office, kitchen, dining, living, and master bed/bath. Of those rooms on the main floor, only the master bedroom has an actual door closing it off (though the house isn't what you'd consider an "open floorplan"). The central thermostat is in the middle of the house on a wall that is in a straight-line to the front door, and directly next to the stairs (going up and down). As a result, the office (closest to the front door), master bedroom (farthest from everything on the main floor), laundry room (opposite in the other direction from the front door), and bedrooms upstairs can all have some significant differences in temperature from the main thermostat - the two upstairs bedrooms in particular. In the summer, the main floor will be perfectly comfortable but the upstairs bedrooms can easily be 10-degrees warmer. So, during the day, I have the system set to monitor occupancy and use ALL of the different sensors to average the temperature for heating/cooling. But at night, I have it set to ONLY use the two upstairs bedrooms as for calculating the house temperature. My wife runs hot anyway, so if our bedroom gets a bit extra cooling on those summer nights, no issue for us. But it helps the kids stay comfortable.

 

I installed a Nest learning thermostat on Friday night. My house doesn't have a C wire, which is no big deal. From what I've read, the Nest battery lasts up to 2 years and it's rechargeable with a USB cord. Just pop the Nest off the wall and plug it into the USB for an hour or two. I had to do this anyways before I installed mine as it came from the store with a low battery.

 

Our 1970 house did NOT have a C wire, so I couldn't install the Google thermostat. It kept throwing errors as I didn't know this was the case, so it got returned.

We had a fancy Bryant one that konked out, so ended up with a basic programmable, touch screen, Honeywell 7 day for $50. Just read @Outbound post and maybe we could have maid it work...oh well.

I'm not into all the Smart features, so didn't worry too much about it. We caved last year and allowed the kids to have Google Home speakers and they still freak me out and I rarely if ever use them.

We set it and forget it. It has vacation, weekends and weekday modes...so it's enough for me.

 

Get a programmable t stat and call it a day. I’m a tech and put a nice 17seer unit in our house last winter; the last t stat I would ever put in would be a smart t stat.
As others have said, you should be ok if you don’t have enough wires.

 

I've installed 4 of them. One in our old home, one in my special needs bro-in-laws home so I can monitor the temp for him, and 2 in this home (upstairs and downstairs). They are pretty easy to install - the app will walk you through it and asks you what wires you are using on your old thermostat so it'll tell you where to put them on the Nest. I love them.

No special wiring - it sounds like you probably have the wires you need already. if not, it'll tell you before you uninstall your old thermometer.

 

I don’t adjust mine a whole lot but I do the same thing with my temperature sensors. Helps a lot in an older house. I also use the vacation setting for anytime I’m traveling. Definitely makes a difference and is nice to have the house back to temp when you arrive.

the other super nice thing is temperature alerts. My parents were out of town and got the alert that it was down to 55 degrees. I went to check it out and the furnace was dead. Got it fixed. Otherwise it could have been a real bad time in feb in the Midwest.

 

This 100%. I'll never have one without remote sensors again. No reason to set the temp for the house based on an empty hallway. With the sensors the unit tries to balance across the different rooms based on occupancy.

 

Keep in mind that whatever you get will only be as good as your WiFi.

if your wifi drops out often or you have range issues, get those taken care of otherwise you will not be happy with your purchase

 

The Nest doesn't require the C wire in most cases.
Check with your state to see if they have rebates or coupons for energy efficient thermostats. Here in Oregon, you can get a $100.00 off coupon.

 

If you're wondering if they're worth it, mine paid for itself in about 3 months. I got the Nest learning thermostat. It was $250 at the time, minus my $100.00 coupon.
Attached is my gas usage. Last year my average gas bill was about $100.00 a month. This year the highest one so far is $21.00. My electric bill has also dropped quite a bit as well.

 

I've had my nest for a few years now and when I installed it I just copied the wiring of the old thermostat. Well, every couple days it would drop from my wifi and I would have to keep reconnecting it. Got to looking into it and realized it needed the C wire. I assume it kept dropping wifi due to a power saving feature from not having constant power. Luckily the cable ran to the t-stat had a few extra unused wires in it. Hooked up the c wire to the t-stat and the other end to the furnace motherboard and haven't had a single problem since. So yes, you don't 'need' a c wire for a nest but be prepared to keep reconnecting it to your wifi. Unless something changed for the newer versions??

 

The “C” wire is needed for constant power. Without it, the Nest T-stat will not stay connected and batteries drain over time.

 

Google mentions this could be problematic if your system isn't running enough to charge it. When a C wire isn't used, it takes power from the system when it's running. It has a mini USB on the back to charge it to avoid that problem.

 

For my application the nest needed a C wire I didn’t have. Ended up finding a pretty straightforward plug and play solution on Amazon to get the thermostat constant power. It’s worked well ever sense.

 

Ac guy. Easy answer is if you have a digital tstat now and don't have to replace battery all the time you are good. FYI not a fan, do not use.

 

Ok, thanks everyone for the info! I think I might be out of luck though, because my house is 1981 so I don't think I have a "C" wire, as I have to replace all my batteries in the thermostats every year. Will look when I get home tonight.... Won't do it until winter is done anyway.

-T

 

Yep, literally every HVAC guy/girl I know says this same thing. We had nothing but issues with ours the first year we owned it; I'm waiting for it to break again so I can get something different/better.

 

I certainly can not speak of the much much much colder climates some of you live in with natural gas heating and turning the tstat up and down all the time might save some money, but it is a misconnection here that turning the tstat up during our 9+ months of cooling while you are at work or at the store saved anything. If you keep the house at 72 when you are there, turn it to 78 while at work and then back to 72 for when you return you have saved nothing. cost just as much to bring it back to 72 as it did to just leave it at 72. I am pretty sure the number of hours is 18-24 to be unoccupied before a savings is seen. Thank God the wifi tstat is not heavy in restaurants (my specialty), many number of calls at $100's a piece to tell the chain location with new employees every week that the ac is fine you have some problem with your wifi and need to call them. Sorry your kitchen is 95 degrees. I can disconnect all this house shit, connect a regular tstat and hang it in the duct work on the roof for $100s more if you cant get anyone to figure out the store wifi. Stuff like that belongs in computer rooms and such that have nerds available all the time. Always fails and I have 30 years experience seeing it fail when some new tech is added to old equipment to improve energy use and left with min wage workers or a manager that has worked 100 this week at 40 hours pay. Set it and leave it alone unless you are going to be gone over 24 hours.

 

We leave ours at 20.5c (it's a battle between my family and me for 20 or 21).

Unless we go on holidays for a week or more, I never change it.

 

I usually keep mine around 60 with an occasional turn up to 65 if I get a chill. I want the fancy thermostat more for winter, when I am at work for 12-14 hours, so I know if my 35 year old boiler stops working before the pipes freeze! I live alone, so there is no one else home when I am not, thus it would be a safety thing to prevent more damage...

-T

 

You're assuming I bought it primarily to 'save money.' I didn't. I bought it primarily because

a) it was on sale
b) I needed a way to be able to set the T-stat turned down while we were away (e.g., vacations), and then turn back to normal on our way home.

I pretty much do set it and leave it alone. The main issue we've had is that for some reason, literally every time the HVAC guy comes in to do their checks, they have to disconnect the T-stat (which is easy to do), but after that nothing less than a full reset of the T-stat gets it working again. It only happens every year or so but it's still an annoyance.

I'm largely in agreement with you - constantly futzing around with the temperature wastes energy, if anything. Once this one breaks for good, I plan on getting one of the most basic Honeywell T-stats that can be remotely adjusted. (Unless you've got a better suggestion - reliability is my main concern.)

 

Same here for the most part. Constantly adjusting it wastes more energy than it saves, I believe.