Nest changing by itself. From 50 to 90 its got a mind of its own

[AServos]

Hello

Our Nest keeps changing on its own randomly. It will drop to 50 or change to 89 or 90. 

We have spent weeks with Google Tech support chat who after being escalated over and over say, we have run out of options, please feel free to buy a new product.

We have:

Factoy reset several times, created a new profile with no schedules and no learning turned on. Still it auto sets itself to random numbers we have never put in. (Its favorite is 50).

Some days it does this twice or three times in a day, other days its only once. Surely there is a fix other than being told to buy a new product. 

Help please.

[Ashepherdson]

Does your furnace have a thermostat or any other controls that are integrated into the main unit?  Has the thermostat always done this since you installed it or is this new? If new, when did it start happening ? Was anything at all added or removed from the network when it started?  Who in your house has access to the thermostat?  

[AServos]

It started a couple weeks ago and nothing has changed with equipment both HVAC and Nest or network. My husband and I are the only ones with access. Google support who we have worked with for weeks Basically said N idea, you are out of warranty we invite you to buy  new one.

[GarrettDS]

Hey there,
Just wanted to jump in here to check to make sure that you saw the response from Ashepherdson. Shoutout and huge thank you to Ashepherdson for the help here. Please let us know if you have any other questions or concerns as I will be locking this in 24 hours.

Have a great day.
Garrett DS

[GarrettDS]

Hey folks,
It looks like we haven't heard back from the OP so I'm going to go ahead and lock the thread. If you have any further questions or concerns, feel free to create a new thread.

Have a great day,
Garrett DS
 

[Frustratedddd]

Which model? 3rd Generation - Europe?

3rd generations can have problems with the software in the base ring connector.

You may have purchased a new thermostat, and left the original base the Nest fits to in the box.

Should that be the correct, swap them over and use the new one.