Thermostat shutting down ac then starting it up again immediately

[AlexaNest]

Subject pretty much covers the problem.  I saw this might be due to not having a common wire, but this just started happening a month or two ago.  Is this because my internal battery is now depleted?

[Jeran]

Hey there AlexaNest,
 

Welcome to the Nest Community Forum! I'd be happy to help you look into this issue, as I can imagine it's pretty confusing. You mentioned that you do not have a Common wire, which could be affecting your AC activation. Would you be able to go into your thermostats Settings > Technical Info, and give the readings for VOC, VIN, and IIN? Here are the expected readings:

VOC

• between 29 to 42V 

VIN without common wire

• between 29 to 42V (HVAC isn’t running)
• 6 to 7V (HVAC running) 

IIN without a common wire: 

• between 20 to 40mA 

I look forward to your response, and if you have any other questions or concerns for me, please let me know!

Best regards,
Jeran
 

[AlexaNest]

Thanks for the reply.  It appears my Battery voltage drops below the minumum at times.  This is causing the Nest to use the battery backup.  But now the batteries (which aren't replaceable) aren't holding much of a charge and I have to take the unit down every week or so to charge it with the USB port.  Nest confirmed this via chat support, but are refusing to replace it despite this being a $350 that is now going bad after less than two years.

[Jeran]

Hiya AlexaNest,

That's no good. I'm sorry to hear that Nest Support is having some issues replacing the device. Just out of curiosity, how strong is the Wi-Fi connection to your Nest Thermostat? If the connection isn't very good, the batteries use a lot more power staying connected to a weak connection, rather than a strong one. Perhaps moving the router closer may help if the Thermostat is further than 20 feet away.

Also, have you received any error messages from the Thermostat? If so, we could look at the code and see if we can find more solutions.

I look forward to your response on this.

Best regards,

Jeran

[AlexaNest]

The house has a strong mesh system so wifi isn't an issue.

I've received one other error message from the thermostat (it seems to be related to the low battery): it let me know that all my nest sensor - I have 3 - disconnected simultaneously

[EdwardT]

Hi folks,

Thanks for letting us know. I'd love to know more about this. It's possible that this has something to do with how your Nest Thermostat is getting power from your system. Could you tell us how your Nest Thermostat is wired and share your power readings?

Thanks,

Edward

[AlexaNest]

The power readings are good - verified by Google tech support - but I suspect the batteries on the unit do backfill power and recharge at times which has worn them out so they no longer hold a charge.  Support is sending me a replacement unit and I'm either going to hook up a common wire when I install it or install it with the nest power connect to ensure power continuity.

[EdwardT]

Hi AlexaNest,

Thanks for the response. I'm glad to hear that you're getting a replacement from our team. Let us know how it goes when you receive it.

Thanks,

Edward

[EdwardT]

Hi AlexaNest,

I wanted to follow up and see if you are still in need of any help. Please let me know if you are still having any trouble from here, as I would be happy to take a closer look and assist you further.

Thanks,

Edward

[AlexaNest]

Well the replacement thermostat doesn't turn correctly.  By that I mean at certain parts during the turn the friction on the unit goes way up and is actually very hard to turn.  Other parts of the turn it goes back to normal.  Not good. 😞

[EdwardT]

Hi AlexaNest,

Thanks for the update. I'm sorry to hear that you're having an issue with the replacement that you received. I would suggest responding back to the email from our support to check your options.

Thanks,

Edward

[AlexaNest]

Thats' what I'm doing.  No response yet. 😞

[EdwardT]

Hi AlexaNest,

Thanks for the response. Could you also share the case number of your interaction with our team so I could investigate further?

Thanks,

Edward

[AlexaNest]

Got a reply back this morning but haven't heard back since.

5-9141000032911

[EdwardT]

HI AlexaNest,

Thanks for providing the case ID. Our team is looking into the video that you sent. Let's continue the conversation there as there are information that we need that can't be disclosed publicly.

Thanks,

Edward

[EdwardT]

HI AlexaNest,

I checked your case and it appears that a replacement has already been processed. I will be locking this thread now. Please feel free to create a new thread should you have some more questions or concerns in the near future and we'll be more than glad to help.

Thanks,

Edward

[dware22]

Following, experiencing an with AC turning off when temp on schedule change although there is at least a 3 degree difference in temp and cooling. Example 76 Cooling and 79 temp on Stat...goes to delayed 3mins then turn right back on.