Batteries not recognized

[Bbanerdt]

Yesterday I got a message on the unit saying to replace batteries since they are low.  I did that, and then it said “check batteries”. I replaced them again, but same message.  I was able to bypass the message to use the unit, but today I replaced the batteries again, and when I got the same message, I decided to do a factory reset.  Big mistake.  Now I need to set it up, but can’t because it says I don’t have batteries in the unit.  What to do?

[virnab]

Hi Bbanerdt,

Thanks for reaching out to our community.

I’m sorry to hear that your Nest Thermostat (2020) is not recognizing the new batteries. Even though you replaced the batteries twice and performed a factory reset, the device continues indicating, “I don’t have batteries in the unit.” No worries, help is here.

Before I start further troubleshooting, let me ask you a few questions:

1. Could you please confirm what type of Nest thermostat you have?
2. Are you using AAA 1.5 V alkaline batteries, such as Energizer AAA 1.5 V Alkaline Battery?
3. Could you please check the C wire connection or install a C wire to provide consistent power to your thermostat?

In the meantime, I recommend you check the following instructions to replace your Nest Thermostat (2020):

1. Pull the thermostat display off the base.
2. Remove the old batteries from the back of the thermostat display.
3. Insert the 2 new AAA alkaline batteries.
4. Push the thermostat display back onto the base until it clicks into place.

Some systems, including heating-only, cooling-only, zone-controlled, and heat pump systems, require a C wire or the Nest Power Connector. Go to g.co/nest/cwire for details.

Thanks for your kind attention; I will be looking forward to your answer.

Best regards,

Virna