NEST Stainless Steele 3rd gen - Now getting Low Battery and doesn't seem to be charging

[SonnyHung]

I purchased this NEST 3rd gen back in October of 2018, and it's been working well over all.

Y1, W1, and RH: these are the wires used in my previous thermostats

My house is from the late 40's early 50's so we have original cloth shielded wires.

The prior thermostat used these three wires and I labeled them with the stickers provided one by one when I did the installation.

In the past after I installed it there were occasions when would have a low battery issue and stop working. This occurred 4-5 times over the past five years. When I originally installed it the wires going to the original Thermostat were short so there wasn't much slack when connecting to the Nest Base.

Basically to resolve the issue I would take the NEST off the base, and reseat it. If that did resolve the issue I would  then check the wires. My thoughts were that maybe they had corrosion or something impeding a clean connection. This would often resolve the problem.

Lately the NEST lost connection OR turned off. A quick fix based on the manual was to charge the NEST manual using a micro USB cable to a charger. Then reseating it back on the base and we were all good.

What should I trouble shoot to figure out why the NEST is charging consistently now using the low power from the thermostat wires? Could it be resistance of the wires? Maybe the power adapter on the wires is acting up and is about to fail? Any help would be appreciated.

 

[Houptee]

Run a new thermostat cable with 5 conductors they sell it at the big box stores 50ft and 100ft.

Connect a real C wire use blue, on the system end, and at the Nest.

[SonnyHung]

Thanks for your suggestion. In this case our home is built in the late 1940's thru early 1950's. The walls here are not constructed of plaster board. I think it's Lath and Plaster, and in the ceilings where a contractor added new lights in our kitchen it looks almost like there was a thin layer of cement. Being that it's likely not as easy to install a new thermostat cable I'm investigating my options.

[Patrick_Caezza]

Usually, I would say to just use the Google Nest Power Connector, but on this one, I would strongly run a new thermostat cable if you can.

Post a picture of the terminal block on the control board in the furnace if you can. If there is no control board and only a wire nut connection, post a picture of that and provide the manufacture name and the model number of the furnace.

[SonnyHung]

Thanks for your suggestion. In this case our home in addition to my reply to Houptee's suggestion doesn't have a newer Heating System like a Furnace mentioned in your reply. we have an Oil Boiler - luckily not the original one, but was replaced back in 1984 with a Peerless unit. I see a Burner Controller on top of the burner itself. I see on the back left side a Temperature Controller for the hot water settings. On the Front left corner looks like a Low Water Cutoff. On the Front left is the Boiler On/Off Switch. And on the ceiling I see a Transformer on top of a Electrical Box. . All of the wiring is in metal piping. Coming from the Transformer there are wires going into a flexible metal conduit disappearing into the ceiling likely going towards the NEST located in the Living Room on my first floor.

At the NEST the wires are cloth shielded their colors are White (Rh), Red (Y1) and Blue (W1). So based on this I'm assuming this was done likely not by standard, and/or could have been redone by the original home owner since they were DIYers and had tons of tools in the basement that I now own after purchasing our home.

To help others I will mentioned I did a bit more internet research on Google, and on YouTube of others discussing this same issue. Most are dealing with Furnaces or HVAC systems. None mentioned my exact setup as they all had 4 to 5 wires minimum connected to their old thermostat, and were running a new thermostat cable with one more wire (5 to 6 wires) to add the C wire..

I purchased a 24V/500mAh Power Adapter with 25 feet run that had the leads tinned. The wire with the black marking I connected to (C), and the other wire connected to (Rh); but instead of (Rh) others suggested (G). After installing the Power Adapter and reinstalling back my NEST I then plugged in the Power Adapter and NEST Power right up.

*I wanted to use the Google Nest Power Connector but all instructions I saw dealt with installing at the Furnace or HVAC system, and not at the NEST.

[Houptee]

The Nest and any thermostat is basically just a switch.

It has R + input and when it wants heat on it connects R to W so power goes out on W to the system and it fires up.

The difference is the smart tstats need constant power to keep them online and wifi.

So they need R+ and C- aka common.

The type of furnace doesn't matter it just needs R and C and then the return wire W to trigger in your case oil burner.

If you can see in the basement the old wire coming down thru the floor then you can go to the nest and tug on the wire see if it moves freely and not stapled to the studs in the wall.

If its loose then you buy new wire and securely attach them together and pull it thru the wall.

[SonnyHung]

Thanks, unfortunately I can't, 'see in the basement the old wire coming down thru the floor'.

The wires from the Boiler head up to and along the ceiling in a rigid Metal Conduit Piping, connected to an Metal Electrical Junction Box where wires exit and connected to a Transformer mounted on Junction Box's metal cover plate. The wires go from the Transformer back into the Junction Box. From there I have no idea where the wires go. They either travel behind the cement board ceiling OR possibly in a flexible metal conduit towards the NEST. It's about a 15"+ run to where the NEST is located on the 1st floor. Part of the ceiling is cement board, some of the way is closed up with panels, and the rest of the way is ceiling tiles.

It's a bit much work for me at the moment as a DIYer so my solution of adding the Power Adapter to resolve the C wire is the best option based on my situation and skill level.  The thermostat cable is not easily visible the most of the run, and what is visible is not easily recognizable as Thermostat Cable for my untrained eyes. I do agree with your suggestion, but that will have to wait for bette weather and more time. 

[Markjosephp]

Hello SonnyHung,

I know it has been a while, but I wanted to ensure that everything was covered here.

How's it going with installing a Nest Power Connector? Still need our help? Let us know so we can assist you right away.
 

Regards,

Mark

[SonnyHung]

I ended up purchasing a power adapter and wiring it in after further investigation. It's working now, but wish Nest provided simple clear instructions for installing a third party power adapter as that would have been a lot easier than investigating and looking for others who wrote up technical  specs on what to purchase and how to install.

[Markjosephp]

Hey there,

I'm sorry for the trouble the installation process may have caused you. We're looking for ways to improve, and we'll take this as feedback. Also, I wanted to ensure that everything was covered here. If there’s anything else I can help you with, please let me know. Otherwise, this thread will be locked within 24 hours.

Thanks,

Mark