Wow this happened to my family. We didn&#x27;t have heat for I think 5 hours. Now we are in the SF Bay so it didn&#x27;t get crazy cold but I had a wife telling me to fix it and the stupid thing wouldn&#x27;t come online. I chalked it up to one of the kids pulled the unit from the base plate and the battery drained.<p>It seems like a GIANT bug to me that the Nest won&#x27;t come back online till the battery is almost fully charged.<p>I &quot;fixed&quot; it by putting our old thermostat back in then I put the nest back a few days later.