The Nest thermostat

That's not really a problem you can fix with a single thermostat. You've got multiple issues here.

You really need multiple zones. I've got a three story house, though the third "story" is a finished attic. You really want a separate zone for each story. In my case, the same heating/cooling system serves the 2nd and 3rd floors - there's an electronic gate which determines whether the heated/cooled air goes to the 2nd or 3rd floor. The 2nd and 3rd floors each have a thermostat. The thermostats don't know that they're being serviced by the same system, they just call for heat or cooling.

The first floor is another zone, but it's served by its own system. That's a total of 3 thermostats and 3 zones.

The other problem is that your AC system is too small for your house. Left to its own, my 3rd floor gets really hot - it's a finished attic, as I said. 90+ easily. However, if the cooling system is running, it has no trouble keeping the heat under control, and never runs 24 hours a day.

Not everything works perfectly here, though. While I don't have AC issues, during the winter heating the 2nd floor ends up sending about half the heat to the 3rd floor. Probably because the vents are in the ceiling. I put a door closer on the door to the attic, but it didn't help much. I deal with this by keeping the 2nd floor somewhat cold. The 1st floor is generally 68, the 2nd floor 64, and the 3rd floor ends up being 70 just keeping the 2nd floor at 64. It's not really a problem I see as fixable short of converting back to radiators on the 2nd floor.

Check to see if your system has a damper. I didn't realise we had one until our system had an overhaul and the guy showed it to me. In the summer, you adjust it so that a majority of the cooling goes to the 3rd floor, and it helps a whole lot more. It, along with the thermostat, has helped a lot.

We leave the auto feature, since we really haven't had to fiddle with it much. It's set at 77° most of the day, and drops to 75° in the evenings, since my SO likes it cooler.

For clarification sake, by "tri-level" I mean split level. Each staircase is a half staircase, and each half of the house has 2 floors (making a total of 4 including the basement). This makes it difficult for the natural tendency of air temperature to work. (In the winter, heating the downstairs only has one path to the upstairs, and that's via the central stairwell).

Yeah, that sounds like you need to consider a more complex HVAC system. Which is expensive compared to just changing the thermostat, but if the downstairs has no source of heat except air moving from the central stair, that's got to be a problem. We paid about $15k to replace the radiator system with two forced-air HVAC systems. It's not so much that we didn't like the radiators, though the one in the bedroom took up an inconvenient amount of space, as we wanted AC. The contractor argued that if we were going to have a forced air AC system, it might as well also handle heat, since it's just a matter of the water temperature in the heat exchangers.

Heating works OK in the house. AC is the bigger problem. We close the vents downstairs in the summer so all of the AC goes upstairs. Downstairs and the main floor get plenty cool. And in the winter, we open things back up so heat comes out downstairs. It's not like it's doing a horrible job at AC, it's just is hard to get it lower than 75 on an exceptionally hot day.

Hehe, I also registered so I could post!

I purchased 2 NESTs for my house and just got around to installing them as we were doing a renovation. We are using in floor hydronic heating with 3 separate heating zones along with a spacepak AC system.

At the moment, we have the upstairs NEST controlling the upstairs heating zone as well as the cooling. I thought I'd have no problems with wiring but now I realize that my 5 wire Tstat wire is barely enough. I'm using Rh W Rc G Y1. I would have been nice to have a 6th wire for C. Since I ran all the Tstat wires and did home runs all back to the mechanical room, I do have full control of what goes where. I hooked up the second NEST with Rh W Rc C so that I could get the common wire for the second NEST.

I actually have a 2 stage cooling unit and I'm wondering if I could actually split the duty of the 2 NEST thermostats.
- Remove Fan only G wire (until winter time) and replace it with C for upstairs.
- Move the Fan only G wire to the downstairs NEST. Think it could just control the Fan only?
- Have the Upstairs NEST run Y1 and downstairs run Y2 if it gets hot enough

Though the trend seems to be that the downstairs is about 0.5 - 1.0 degree (Celcius) hotter than upstairs so maybe have upstairs control Y1 and downstairs control Y2. I can't tell if my AC compressor needs to see Y1 circuit closed before Y2 would work. i.e. if the NEST closes Y2 while the other nest has Y1 open, if the AC unit will work properly. Definitely going to try to move the Fan only G wire to the downstairs NEST tonight and see how that works.

I'm also seeing a strange phenomenon where the NEST won't keep the cooling on for more than about 5 mins. It cools for 5 mins, then turns off even if it hasn't reached its' target. When I go to the NEST it says delayed for 5mins and counts down. It basically keeps cycling 5 on, 5 off. Called NEST and they say it might be a voltage issue (which is another reason I'm trying to get that C wire in and wished I had run an extra pair of wires)

While on vacation last week, our AC decided to die so I'm looking at getting a new furnace/AC this week. (The current one is 23 years old, so I guess it's time). The new one is a Bryant 2-stage high-efficiency furnace plus A/C. In addition, the furnace has humidity control built in. It is my understanding that features like the 2-stage and humidity will be run automatically by the furnace's control board in the absence of a thermostat that directly controls it.

In my house, the current thermostat only has 4-wires for wiring (Rh, W1, Y, and G). Having been reading reviews of the Nest lately, the lack of a C wire is slightly concerning to me among reports of insufficient charging of the Nest through the pulsing-method. Because of the wiring that can't handle a 2nd stage and the Nest not being able to control humidity, I've been considering the Ecobee EB-Stat-02 thermostat. The other huge bonus about this for my particular situation is that the Ecobee uses an interface module at the furnace where most of the wiring happens, and the thermostat connects with only 4 wires (exactly what I have). This would let me circumvent my limited wiring issue.

On the other hand, the Ecobee doesn't seem to be nearly as easy to use as the Nest. Not that it's hard, it's just a lot more traditional in terms of programming. The fact that we completely ignore our programming now (and that my wife treats the thermostat as an on/off switch) makes the learning capability of the Nest pretty desirable as well.

Any advice for my scenario?

New Nest is coming out, and the old nests will get the new software, yay! It's also compatible with more systems, so if your system didn't work before, it might now.

I had a battery drain problem. I didn't like the idea of the furnace pulsing, so I inspected the wiring closer. I used the R, G, W and Y, and had two extra wires coming out of the wall. One blue and one brown. My townhome was built with an option for a second unit, so I assume those unused wires were for that purpose. I wound up taking the brown wire and connecting it to the C dock on the Nest. I went up into the attic and connected that end of the wire to the C 24v connection at the furnace control panel.

PROBLEM SOLVED!!!

So is there any big difference between the old and new? The old one's $50 cheaper, and it seems like the only difference is that it's a little thicker?

I know when they released the new ones they added more support for other kinds of ACs, but I don't know if that was just software or if the hardware is different for those other AC types. If it's just software then the Gen1 and Gen2 are identical.

A cool thing (at least to me) is the monthly email you get from Nest with animated gifs!
Here is my usage for the previous month compared to the month before:

And here are the number of times it considers that energy was saved on the two units:

How big are these things? I ask because the wiring for older thermostats can sometimes be pretty messy coming out of the wall, and the hole for the wiring could actually be bigger than this thing. It doesn't look like it has that much room on its back to put in wires cleanly.

Thinking about suggesting this to my parents who now have iPads and Macbooks and shit, but they're not particularly fond of the programming function of their thermostat.

And I'm assuming you can disable all the useless automatic and "learning" features of the device?

It comes with a backplate that you put on the wall to cover the old stuff. You can disable the automatic features, but they're pretty handy.

I have an issue with 2 Nest thermostats I just installed. I have a heat pump. The one downstairs works fine but the one upstairs turns on and stays on and will not turn off. After its been connected for about 3 or 4 minutes, my unit turns on. I put my old thermostat back on and it works fine, but when I put the Nest on the unit turns onIt does not show that its on (heating), on the Nest either. The bottom unit works fine. Do you think the wiring connection to the one upstairs needs to be different?

I have a 6 wire connection W, O, G, R, C, Y. I tested both Nests downstairs and they both work, but upstairs it will not turn off. PLEASE help!

Someone explain to me the reason the UI comes up so often. Yes, the UI of other products suck, but you set them up once and you're done. Forever. That this has become the primary selling point of a learning device just makes me think it's a big fat pile of over-priced fail.

I saw one person talking about setting their thermostat every night. WTF?

I program my thermostat, sure. Except that it doesn't automatically do DST, so it's running an hour off right now (and has been for the last few months), so I have to manually adjust it. And I could reprogram it, but it's just annoying enough not to be worth it.

No, the bad UI of a legacy thermostat isn't some total killer flaw that makes it flatly unusable, but it's a legit flaw.

Sure, but seriously, reading these threads the Nest fails at everything else. It fails at its primary function! I love a good UI, but if you have a good UI and nothing else then what's the point? Saving the thirty seconds it would take be to change the hour once every six months?

It doesn't fail for me, it works great. Just being able to adjust the thermostat using my phone makes it completely worth it. The autolearning is fine. The auto away works great.

Meanwhile, I got a Nest for Christmas and just installed it today. The install was super-easy, and the insanely over-designed screwdriver they put in the box is very clear signaling about how much this is a fetish product rather than a strictly utilitarian thing.

So as far as I can tell, what I do now is just set the thing when I get home and when I go to bed for a bit, and then it'll figure out quickly on its own what to do? How long do I have to do the manual stuff before it gets it all down well enough that I can ignore it?

A couple of days, and/or you can just go in and set a schedule, too. It will also go through a learning period when you switch to cooling in the summer.

So, after a week of the Nest, I think it's pretty great. It quickly learned what my schedule was (took like a day or two), and then it took a weekend day to figure out what I do on weekends differently, but bam. Just like that, it's now programmed, better and more accurately than my old one that I manually programmed. And I am a tech-savvy dude! For people who never program their thermostats, this thing would be a miracle machine.

Also, it looks great, and feels great, and... okay, this is wifty, but psychologically, it feels different from my old thermostat, such that it encourages me to change the temperature if I want to. With the programmable one, the instant I hit a button, it was in OVERRIDE mode, and it was a big deal, and it made damn sure I knew I was inconveniencing it. With the Nest, I'm just changing the temperature, and that's cool, it'll take my input into consideration in the future so it can serve me better.

About the only weird thing is that it sometimes gives me little messages in the morning that are like stalker notes.

"MY LEARNING IS COMPLETE. I WILL TAKE CARE OF YOU NOW."

"I KNOW WHEN YOU'RE AWAY. I CAN DO THINGS WHEN YOU'RE AWAY."

Fuck, give it the voice of HAL-9000 and I'm sold.

I was wondering if the nest could interface with multiple heating systems. I have a standard forced air furnace. I also have a wood burning boiler outside. The boiler feeds a water to air heat exchanger in the Plenum, and also baseboard in the lower level of my home. Would I be able to put remote sensors downstairs and have the nest be able to read them?

I'm sorry, Dave, but I just can't cool your house down right now.