Gen 3 Learning Thermostat temperature is way off after disassembly

[BeCue]

I have disassembled Gen3 thermostat to see if battery replacement could be done by myself.

I got to the point where I unplugged the control cable, visually checked the battery, and assembled it back.

(only 1 ribbon cable removed and installed back right away)

everything is still functional, but it is definitely reading +4~5 degrees, which is a pretty big difference.

(it read 80 when it is about 75~76 checked with other thermometer)

Is it possible that somehow I touched the thermocouple/sensor? if so, where is the sensor located so I may be able to disassemble again and clean up.  I couldn't find any information online.

or does it takes some time for the thermostat to read the temperature correctly?

[GabrielaG]

Hi BeCue,

Thanks for reaching out to the community. I'm sorry to hear your Nest thermostat 3rd Gen temperature is way off after disassembly. I'm happy to assist you right now.

I appreciate your attempt to resolve the issue. Considering that the Google thermostat is a sealed item, replacing the internal battery in your Nest thermostat can damage the functionality of your HVAC system and your thermostat's warranty; we do not advise doing so.

We don't have any articles or information on how to disassemble and clean the thermostat or regarding the thermocouple/sensor.

Feel free to keep us posted if you have more questions.

Regards.

Gabriela