Nest Learning Gen 3 not charging

[llichlyter]

I've recently installed a Nest Learning Gen 3.    My original wiring had an RH wire and Rh to Rc jumper.

So on the next, I've used the Rh.

The issue is that the battery doesnt' seem to be charging.    On two consecutive days it has gone offline (lost network) due to low battery.   Yesterday I charged it via USB and it was fine and today it went low again.

Is there some troubleshooting to do why it's not getting power to recharge the battery?

[Patrick_Caezza]

How is it wired?

Does it have a C wire?

Post a picture of the original thermostat's wiring here

[llichlyter]

It does not have a C wire.    Here is the original (old) thermostat wiring

wiring 

And what Nest detects

Nest wiring 

I didn't see another way to attach/upload pictures.

[Patrick_Caezza]

Those links are not working.

You can add pictures to your reply by clicking on the camera icon at the top of the reply window.

The Nest Learning Thermostat says it can work fine without a C wire. The real-world fact is that without a C wire, you'll experience power problems at some point.

There are a couple of ways to add a C wire, first is to use a spare wire if there is one going from the thermostat to the furnace/air handler. If there is no spare wire, you can run a new thermostat cable with more wires, or you can use the Google Nest Power Connector.

[Markjosephp]

Hello there,

I wanted to ensure that everything was covered here.

Thanks for the inputs, @Patrick_Caezza.

@llichlyter, I also found an article that would tell more about how the common wire works with thermostats. Also, could you please check your thermostat's power readouts? You can find these in your actual thermostat's Technical Info settings.

Feel free to let us know if you have more questions.

Regards,

Mark

[llichlyter]

Well, it's not all well.   It would seem it gradually loses power...like it gets a little charge but not enugh to continually maintain the battery.  So every so often it runs down, I charge it offline and have to put it back on.

When it's fully charged, the battery reading in the Technical info is in the 3.8 - 3.85 range.

I'm very disappointed Google would say the device is compatible, but really, you need a C wire to make it work correctly.    Not good engineering for a device this expensive.   And expensive to run a C wire.

[Markjosephp]

Hi llichlyter,

I understand your thoughts about this, and I'm sorry for the experience. Installing a Nest Power Connector would help as an alternative for C wire. It has the same function as how the common wire provides constant power. Here are some references to help you install a Nest Power Connector on your HVAC system.

• Nest Power Connector installation article
• How to install the Nest Power Connector - video link

Regards,

Mark

[Markjosephp]

Hey there,

I wanted to see if you still needed help. Please let us know if you have any other questions or concerns.

Thanks,

Mark

[Markjosephp]

Hello llichlyter,

It has been a few days since your last reply, and we're going to lock the thread within 24 hours. If you have any questions, please feel free to create a new post.

Regards,

Mark