Battery draining on my Nest Thermostat

[rickflynn1010]

I plug the unit into a USB adaptor and charge it until 100% and then reattach it to the wall. Once on the wall the battery drains itself and it is dead by the morning. I used to have the yellow Y1 wire connected but disconnected it b/c the a/c is no longer working. I thought that might be the issue. Current setup

[Patrick_Caezza]

@rickflynn1010 

The thermostat can't keep the internal battery charged without the yellow wire.

Install a C wire and that will fix the problem. There appears to be a spare blue wire that you can use. Just connect it to the C terminal on both ends

[rickflynn1010]

Even with the yellow wire connected, it wouldn’t hold a charge. 
Also, a lot of what I read online is to not use the blue wire if I don’t have a heat pump. It used to work fine without the blue wire. I don’t know what happened? 

[Patrick_Caezza]

@rickflynn1010 

Not sure where you read that,  The normal use of the blue wire is as a C wire, and sometimes as a B wire for a heat pump install.

Nest thermostats are designed to steal power using the Y terminal.

You said the A/C is no longer working, does that mean there is an A/C installed and you are not using it?

You have what appears to be a dual-transformer system and without the Y wire install the system might start acting up.

[rickflynn1010]

We have had the Nest for a while and it worked without issue without the blue wire connected. The a/c no longer works and an animal may have chewed through the wire. When I remove the Y1 wire we can use the heat and it will hold a charge overnight but by morning the battery is dead again.

I have attached new pics with what is displayed on the Nest.

[maedacortez]

Hi rickflynn1010,

Thanks for reaching out. I understand that your Google Nest Learning Thermostat 3rd generation is showing the E80 error code. I know that can be frustrating. No worries, I'm here to help!

As you mentioned that the A/C is no longer working and you disconnected the Y wire, I recommend performing a factory reset to change the  configurations at only heating to do this  Go to Settings > Restart > Factory Reset.

After performing the factory reset, you'll need to set up your Nest Learning Thermostat 3rd generation again. When your device asks for your system, select that you have a fan and heating system and if you have single or dual fuel.

Please let me know if this helps! 

Regards,

Manuel

[rickflynn1010]

Hi Manuel,

So when I do this, I will need to connect the blue wire this time in order to run power to the nest instead of the Y1 wire? 

[SoriaD_]

Hello @rickflynn1010  

Thanks for reaching out to our Nest Community. I'm sorry for all the inconvenience with this E80 code on your Nest Learning Thermostat. Don't worry, I'm here to help you.

I appreciate all the details and the steps you tried to find a solution for this situation. Certainly this is not very common after working relatively well.

My team seeks to provide you with a solution for this. I would ask that you use this page to contact a specialist agent who helps you with the necessary troubleshooting steps to identify the reason for this situation.

Similarly, if the situation arises within your unit, our team can provide you with the necessary information to proceed with your case.

I appreciate your time and effort to solve this, and my team will do everything for find an answer for this inconvenience.
Do not hesitate to keep posting; if you have another doubt, we will be here to help you.

Best regards,

Douglas.