Nest (base) thermostats not seeing W, Y and G wires

[dhs910]

I (or rather my HVAC techs) just installed a new zoning controller (Ecojay Smartzone 4X) with two new Nest thermostats (the base model) upstairs and downstairs, and everything went fine. Except that neither thermostat sees either the W, Y or G wires. They do detect R and C, and also correctly detect that the O/B wire is not connected.

We've checked continuity on all the wires and also confirmed proper voltages. We did go ahead and restrip/reseat all of the thermostat wires, without any changes. Per a reddit discussion, we also restarted each thermostat, and then did a factory reset/restart. Also no luck.

Ecojay tech support said that their controllers were compatible with Nest thermostats. I just checked with them again to be sure but haven't heard back.

What I find especially noteworthy is that all of the signaling wires on two different thermostats are not being recognized by the app AND that the thermostats themselves don't indicate any wiring problems. But since I don't know how the app and the system decide if there's a wiring problem, I don't know how to interpret that. I just know the AC doesn't work ;-).

Anything else I should do?

[Patrick_Caezza]

@dhs910 

Can you post a picture of the Zone Controller wiring and one of each thermostat wiring?

[dhs910]

hi,

I'll do that shortly - taking the dog to the vet this morning, but will do so afterwards. But I should note that the HVAC tech (from a local company with a good reputation) did the zone controller wiring, and he rewired at least one of the thermostats, and recut/stripped each wire in the process. And moreover, after futzing around (that's a technical term) looking for thermostat wiring issues, as a last step they checked and found that the cooling signal was getting through to the control board on the outside unit. Unfortunately the board connector was flaky and so the AC still wasn't working.

But at this point, I think that this may be a software or even hardware issue with the base Nest thermostat - it isn't reliably detecting or reporting connection status. And it's inconsistent - original both thermometer were reporting problems with the Y, W and G wires, and now the downstairs one is reporting only a problem with the W (heating) wire. Weird.

A question: how do the connectors on the thermostat work? I've been using connectors like that for decades, and you push on a tab (or something), insert the bare wire, and release the tab, which then holds the wire in place. These connectors seem different, as though you're supposed to just insert the wire without pressing the tab.

Anyway, I'll post pictures later this morning.

Thanks!

[dhs910]

[dhs910]

The first picture is of the downstairs thermostat wiring, which I think one of the techs redid yesterday. The second is the upstairs thermostat which the tech redid yesterday as I watched him. The third is the overall zone controller, and the fourth is the thermostat connections to the zone controller.

As I noted in my other post today, this *seems* to be working - both the furnace and the outside AC unit are seeing signals (furnace works, AC unit doesn't because of a separate connector issue), but the Nest thermostats indicate that some of the wires are not connected. Any ideas?

The tech is coming over to hopefully fix that AC unit, and afterwards I *may* try to redo the thermostat wiring again. But I'd really like to understand why this is failing, especially since one of the unit only shows a bad W wire while the other shows bad W, Y and G wires.

As I also mentioned in my earlier note from today, I've never seen connectors that work like this. Apparently you just insert the wire, and there's a mechanism that clamps onto the wire to hold it into place, and that process depresses the tab. Is that right?

[dhs910]

Well, the HVAC tech came yesterday and fixed the problem in my outside unit, and so everything works now, except for the wiring status issue. It still doesn't detect the non-power (Y, W and G) wires, even though they obviously work.

I'm unfortunately outside Amazon's return window - it took a while to get this project done. So I'm going to try to redo the wires again (not really sure why) but if that fails, do I open a ticket with Google/Nest service? How do I do that, effectively?

[JuanCH]

Hi dhs910,

Thanks for reaching out to the community and for the pictures! I understand you were experiencing some inconveniences with your newly installed Ecojay Smartzone 4X zoning controller and two Nest thermostat devices. Specifically, while the Nest thermostats correctly detect the R and C wires, they're not recognizing the W, Y, and G wires, despite confirmed continuity and voltage. You've also confirmed that the O/B wire is correctly noted as disconnected.

Thanks for confirming that your outside unit now functions, but the Nest app and thermostat still don't recognize the W, Y, and G wires. I appreciate all your efforts in trying to get your Nest thermostat device working as expected. I'm here to help! To gather some more details, I'd like to ask the following questions:

• What's your Nest thermostat device? Please check out the following link for your reference: How to tell which Nest thermostat you have
• What is the length of the wire that is inserted into the connector?

Please keep me posted. I look forward to your response.

Best regards,
Juan

[dhs910]

I'm using two of the base Nest - purchased earlier this year.

By length of the wire, I assume you mean the length of the exposed (stripped) wires inserted into the connections on the wall plate. Those are all 1/3-1/2", per the spec. That the unit is functional means that the wires are connected. My question at this point is why the software doesn't recognize that, and why it's inconsistent - occasionally one of the wires (usually G) will show up as connected on one of the units. As I said - weird.

As I said above, I'm going to reset/delete/restart the thermostats to see if that fixes this. I'd like to think this is just stale data but don't know that it won't cause problems later.

[dhs910]

No joy.

I reset the thermometers, turned off power, then restarted - same results. No detection of Y, W and G wires on the thermostat itself. The app shows them as connected.

I then did a factory reset of both thermometers, turned off the power, deleted both devices from the app and pulled the batteries. I then waited for 15 minutes, and turned on the power and re-installed the batteries. From scratch on the app, I added both thermostats, indicating during setup which wires were connected - Y, W, G and of course R and C. But again the app indicated during configuration that the Y, W and G wires were not detected. It did correctly figure out that the R and C wires were connected and that the O/B wire isn't present, although that may be because I reported during setup that the O/B wire isn't used.

And the furnace does work - haven't checked the AC yet but will.

Clearly the wires are connected and working - otherwise the furnace wouldn't work. I still have no idea what it means that the app during setup and the thermostat during operation reports that the Y, G and W wires are connected, nor do I know what it means that the app after configuration reports that Y, G, W, R and C are connected - perhaps relying on the fact that I reported that during setup?

I did find one thing interesting during setup - even though I did a factory reset on both devices, then turned off the power and removed the battery, the thermostats didn't update the software during setup, indicating that the prior software update during the initial install (which took several minutes) was still there.

Suggestions? I'm past the Amazon return window - took a while to find a contractor able/willing to switch out the zone controller. So what else?

[dhs910]

I talked to Google support, who were unable to help me, and spent a lot of my time doing so. The technician then said that he would send a email about contacting a local Google support tech to do an in house check, and that I wouldn't be charged for this service call.

Great. Except he lied to me - the email explicitly states that there is a charge for this visit.

So how do I file a warranty claim to return these?

[JuanCH]

Hi dhs910,

Thanks for following up! I appreciate all the troubleshooting steps you've taken to get your Nest thermostat devices working as expected. I'll be glad to help with the information you need!

The team would like to learn more about this behavior. When you get a chance, please fill out this form and let us know when you’re finished. We’ll have someone reach out to you via email from there.

If you have any other questions, please don't hesitate to post them on this forum.

Best regards,
Juan

[dhs910]

I think I'm through trying to resolve this issue.

Earlier this week I spoke at length (over an hour) with a phone support representative - even installed an app so he could watch my screen, worked through the complete setup again (and again), etc. At the end of this he offered to do an exchange - either in advance (Google would sell me two new thermostats, and then refund my purchase on the return of my two current ones, or vice versa. Obviously only the first works since I can't do without HVAC for over a week. But I told him I wanted to better understand the problem and that I would call back in a day or two.

Which I did, yesterday. After talking more with Google's email support team and Ecojay's tech support, I decided that in addition to being easier to stay with the base Nest, there was a chance that the problem I was seeing was a manufacturing issue that new thermostats might not exhibit.

But the support person I talked to yesterday refused to honor this. He said that I had to send Google a copy of the receipt from the HVAC company and that *maybe* Google would send out replacement thermostats that may be refurbs.

There are three obvious problems with this. First of all, I didn't hire the HVAC techs to install the thermostats, and they didn't note that on the receipt; I also don't understand why you would require this for a product that you advertise as suitable for home install. Secondly, I spent extra $$$ on the labor that the techs put in trying to diagnose what ultimately turned out to be your problem -- your thermostat doesn't and probably can't reliably detect which wires are connected, and yet during operation displays this as a problem. Thirdly, "refurb".

And to top it off, since I'm past Amazon's return window for automatic returns on both the thermostats and trim plates, I asked your support team to do warranty returns on them, and this was declined.

I was, however, able to talk Amazon into letting me return the thermostats (we'll see how that goes) but not the trim plates. So I guess I'm out $25 for that - I'll factor that into my Amazon review of your products and especially your support.

No regards,

Doug