
Ask HN: Is anyone using Nest Thermostat in their home? - codegeek
I have a really old thermostat in my house and it is time to upgrade. Nest is hot right now and just wanted to ask if any fellow HN&#x27;ers have them installed in their homes. Did you install it yourself or called a professional ? What do you think about its &quot;Learning ability&quot; ? How well does it work with WiFi ?
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VLM
No nest here. I've installed a couple thermostats in my house and family
homes. Its fairly trivial work. Looking at the pix of the nest "wiring
diagram" and backplate wiring thingy, it appears to be beyond easy. (edited to
add, I'm complimenting its graphical arts design or whatever, in the olden
days I've actually installed thermostats that consider written docs that "the
3rd screw terminal is the W" no diagrams or writing on the device, to be
adequate, the nest is much better documented and designed) The biggest "fun"
you'll have is if you require lines that don't exist and have to rewire at the
furnace (most commonly not having power at the thermostat)

The most exciting part of thermostat installation is standards are so handy
that there must be dozens of them.

My advice is take a pix of the wiring before you start. No pondering what
connected to what if you get confused later. This is also handy with advanced
car work.

In addition to the pix, draw a map of how each wire connects to what old
terminal and all that. Not necessarily useful as an end product but it does
kind of force the issue of studying the wiring.

Also pull the wire out of the wall a little, and tape a clothes hanger or
something like that to the wire. That way it can't fall into the wall, which
can be quite a puzzle to solve even with the gear to fix it.

Thermostat wiring is much like the old RS-232 standard in that every pin is
supposed to be indestructible and can't be damaged by shorting to any other
pin at any time, and of course Chinese value engineering means thats not
always the case. Shutting the furnace off would probably be wise, even if in
theory its impossible to damage anything by a momentary short ckt.

WRT "or called a professional" note that the profit margin on sales will
motivate them to not be interested in installing your thermostat, rather than
installing their thermostat, and they might not sell a nest. Also a pro HVAC
guy makes money installing major machinery, so unless they're hurting for
work, getting a guy out there might not be easy/cheap.

(edited to add I wrote from a EE perspective WRT wiring and protocols and
pinouts, and one thing I overlooked is the decorative aspect of if you're
changing from a giant rectangular to small round thermostat you'll have some
painting, maybe even screw hole filling, maybe even hold patching to do, and
frankly I donno if HVAC guys will do that kind of thing. Every job an
adventure...)

~~~
codegeek
Thx. Useful advice and information. On second thoughts, I came across
Honeywell's Smart Thermostat and I am leaning towards it based on reviews.
Plus, I somehow don't like the round dial of Nest.

------
jgeorge
I have a Nest an generally love it. I upgraded to it from a previous "smart
thermostat" mostly for new-technology and to support some friends who were
working on Nest when it launched. I have kind of an unusually-shaped house and
the Nest doesn't do well to learn when I'm not home (because of it's placement
I can be in several places in my home where it doesn't "see" me). For me it's
not _quite_ as hands-off as it probably could be, but I've been able to
measure a significant energy savings from pre-Nest to post-Nest home heating
and cooling.

Edit: I installed it myself and as long as your HVAC system is a) decently
installed in the first place and b) not too unconventionally weird, you should
be able to install it yourself. It's mostly just matching up the wire colors
in the wall to the wire colors in the base.

~~~
VLM
"It's mostly just matching up the wire colors in the wall to the wire colors
in the base."

I'd add a minor suggestion to make a wiring diagram of what was there and then
match the letters on the old thermostat to the letters on the new one. I've
seen some weird stuff where the old thermostat works perfectly with the white
wire connected to the "G" terminal... so I'd strongly encourage replicating
that weirdness with the new thermostat and connect it to the "G" on the new
terminal much like the old, regardless of its insulation color.

I think it comes from using non-standard wire and/or remodeling. I remember
running into this with a house that converted from no AC and a humidifier to
no humidifier and AC and the wiring colors didn't match the letters but it
worked perfectly in the end. Or maybe this was the place that had
independently controllable fan but not enough wires to supply thermostat power
so fan control wires were stolen for thermo power and the colors certainly
don't match but the letters did match and it worked.

I suppose the "correct" thing to do is open up the furnace and rewire it the
right way and wire the thermostat the right way. In my infinite spare time.
Also if someone finds thermostat wiring intimidating I'd advise not opening
the cover of a modern furnace, looks like a cross between a water cooled PC
and a bad star trek episode in there...

Anyway the general point is whatever was connected to "G" on the old thermo
had better connect to "G" on the new thermo, and ditto for all the other
letters, and don't worry about the wire insulation color. Make a map
(schematic) and snap some pix before unscrewing anything.

Good luck to OP, its fun to install and complete projects and have a new
techno toy. A neurotransmitter hit like the first time a program passes all
the required unit tests, or hitting vers 1.0 or whatever else.

