Installing NEST Thermostat - two wires

[Tony Hwang]

Hi, Nest 'stat has firmware bug, never heard about it? Off topic their smoke detectors are being recalled.

[trader_4]

onnection, un marked, The system is gas, radiant in floor heating and basic ally if you touch the 2 wires it completes the circuit and you have heat. My nest has a built in battery so it works even when i pull it off the wall . anyways you just need to connect W1 and RH and you are good to go, even i f you get the wires backwards it will still work, i am not sure on if it w ill charge the nest if it is backwards. I am going to take a look at my re lay box tomorrow and verify the color codes. i have both of the wired oppo site so i know they work no matter what.

ry bulb furnace thermostat. There are only two unmarked wires. There's 24 V across the wires.

G, C, etc) they will map to? It has to be the most basic of installations; open or close the circuit.

It apparently has a lot more serious problems. The long list of pissed off customer complaints at Amazon is amazing. Last time I looked, which was months ago, most of the complaints were related to using it in the

2 wire mode, where they try to rob power from the system to power the thermostat. In order to reduce power to make that possible, instead of using small relays like most other thermostats, they used FETs which apparently burn out, don't work, etc. One feature they appear to have that you gotta love is that it can and will install software updates any time it wants to and you have no control over if it does, nor when. Just what you want in a mission critical app. IMO this thing is great if you want a stylish ornament for your wall. If you want a real thermosta t, that works, I'd get a Honeywell VisionPro.

[Tony Hwang]

Hi, I maybe biased as Honeywell retiree, I like Honeywell Vision Pro line my self. Just good for the guy who sold the Nest to Google for 3 billion. Rule is the more a device gets fancy, the more possibility of some thing behaving weird unexpectedly.

[sam E]

If it charges one way it should charge the other. This is 24V AC so polarity doesn't matter. Phase doesn't matter either since there's nothing to compare it to.

[kencarterretired]

bulb furnace thermostat. There are only two unmarked wires. There's 24 V across the wires.

C, etc) they will map to? It has to be the most basic of installations; op en or close the circuit.

I am considering buying a NEST thermostat today. I have one of the basic tw o wire thermostats where I have a white and a red wire. It's the type with the mercury bulb.

The guy came around from the installers and tried installing a nest three m onths ago and told me it would not work on a two wire system. I have heard different stories about this. Some say yes it does work, other say it won 't work without pulling through a common wire (whatever that is, I am no el ectrician) My two wires are red and white BUT I also have two other wires t hat are there, a black and a green one that weren't connected at the thermo stat. I am wondering if I could use one of those wires as a common if need be. I would imagine they are for a future install of a heat pump.

Can anyone advise me on this?.

Thank you.

bulb furnace thermostat. There are only two unmarked wires. There's 24 V across the wires.

C, etc) they will map to? It has to be the most basic of installations; op en or close the circuit.

[trader_4]

y bulb furnace thermostat. There are only two unmarked wires. There's 24 V across the wires.

, C, etc) they will map to? It has to be the most basic of installations; open or close the circuit.

two wire thermostats where I have a white and a red wire. It's the type wi th the mercury bulb.

months ago and told me it would not work on a two wire system. I have hea rd different stories about this. Some say yes it does work, other say it w on't work without pulling through a common wire (whatever that is, I am no electrician) My two wires are red and white BUT I also have two other wires that are there, a black and a green one that weren't connected at the ther mostat. I am wondering if I could use one of those wires as a common if ne ed be. I would imagine they are for a future install of a heat pump.

y bulb furnace thermostat. There are only two unmarked wires. There's 24 V across the wires.

, C, etc) they will map to? It has to be the most basic of installations; open or close the circuit.

Assuming those additional wires run all the way back to the furnace, which is likely, then yes one of them could be used as a common to supply power. If the installer was at all competent, he should have been able to deal with that the first time around.

I looked into the Nest a few years ago and from what I saw, there were a huge number of problems, with most of them involving trying to steal power with 2 wire installations. Things like it shorting out, forcing the heat or cooling to full on, regardless of temp.

I think the Nest sucks for other reasons too. Lots of stories of people saying that they can't control it, it just does what it wants, etc. That's how it's marketed, isn't it? I saw people complaining that if they were home from work, sick in bed, and wanted it to just keep a set temp, it would just keep reverting back to figuring out that because it didn't see movement for awhile, it thought you'd left the house..... I don't need that. For me a Honeywell VisionPro that's programmable works just fine. I would get internet connectivity in my next one, so that I could control the heat from my phone, turn it up when I get back to the airport, etc. Could get a VP that does that for $150.

Also, don't be fooled into some incredible claimed energy savings. Those savings are mostly due to what you can do with any programmable thermostat.

[micky]

This is the wave of the future. If you're just going to lie in bed for hours, you should have gone to a hotel.

Of course you don't NEED it but it's modern, high-tech, and it's what we will all have soon.

There's something about coming into a cold house that seems like part of taking a trip. It doesn't take long to warm up.

I'm sure you're right.

[Tony Hwang]

I strongly suggest you buy something else. Version 1 had big issues with under-rated relay causing a/c compressor burn out when relay sticks. There are many other choices like Ecobee, 3M, Honeywell, etc. They are all WiFi thermostats. I believe 3M one is made by Honeywell.

[Tony Hwang]

BTW, I have wireless(no wires betweeen thermostat and system) and WiFi Honeywell thermostat. I can control it any where in the world using internet. using computer or smart phone)

[sms]

You need three wires for heat only, common, 24VAC, and RH (request heat). It's good to have more wires, one for fan-only, and one for RC (request cool). It would be surprising if the extra two wires you have don't run back to where the furnace is.

You do not want to install a NEST thermostat in "power stealing" mode because it can destroy the furnace's controller board.

[micky]

Of course that means terrorist hackers can turn up the heat in your house. You've been warned.

[Tony Hwang]

High end system has that all taken care off. It won't allow it. It won't cause freezing or over heating due to AI.

[Mark Lloyd]

[snip]

When you do so, are you connecting directly to the thermostat or to a web server that's controlled by the company? If the latter, then someone else actually has control over your thermostat in a way that you don't.

It shouldn't be too expensive for a thermostat to contain an embedded web server, and then YOU connect to IT. I find this very important.

[Mark Lloyd]

[snip]

That's one reason I want a thermostat I control.

BTW, At this moment I happen to be looking at my network router. It's one computerized thing I can connect to directly to change it's settings. No company has access.

[Mark Lloyd]

[snip]

The new system I got a couple of years ago requires 7 wires, since it has 2-stage heating and cooling (not heat pump). They actually put in 10 wires (3 available for future use).

[snip]

[Tony Hwang]

I quit fooling around with wires quite a while ago. Wireless thermostat is so handy.

[Tony Hwang]

That is moot point. Still you have to depend on the Internet for remote access. Nothing in the world is 100%, perfect;y secure. Ever heard of any system scoring perfect security ratings according to mil-spec.? When I was retiring best there was B2 rating. My home network is UTM enterprise class router based, best I could afford. So far never been compromised by hackers. Any way if there is unauthorized intrusion, at least I'll know any way as soon as it happens. BTW, I use wired gateway for outside connection. At least one less worry not using WiFi method.

[tony944]

Miky: what you have it is just Heat Tst. you need to look for two wire type Tst. Two wire can be use also for heat but it require sub control to switch from heat to cool or wisa wersa More sophisticated Tst. would not work for you as is, it must have backup battery. but yes it can still be hooked up to do the job however person must know what it is doing.

This is the wave of the future. If you're just going to lie in bed for hours, you should have gone to a hotel.

Of course you don't NEED it but it's modern, high-tech, and it's what we will all have soon.

There's something about coming into a cold house that seems like part of taking a trip. It doesn't take long to warm up.

I'm sure you're right.

[micky]

No, it's not.

There's perfect, there's almost perfect, and there's far less than perfect.

[mrbeldon]

what did you find out? other than this tony dude is a d*****ad. why are you such punks?