Wow have you got some usability problems, even in the third generation thermostat.
Lost connection due to a power failure. Something had changed with my router and Devolo homeplugs - I think the router may have been updated to do something about the stupid access point isolation it used to enforce.
Unforunately this led to the loss of the thermostat's connection to the internet. Which appears to have prevented the Heat link reconnecting.
First usability disaster. In order to reset the WiFi, I need to get to the reset menu.
You can't get to the reset menu if the Heat Link error message is preventing access to the main menu. If I do a soft reset by holding down the thermostat for 10 seconds, I get a very brief chance to get to the reset before the Heat Link error came up. After about 6 goes, I got there...
After a bunch of resets, and moving the thermostat close to the Heat Link, the thermostat reported a need to shut down due to the battery running low. I plugged it back in, but the shutdown didn't complete. Did another soft restart and amazingly the Heat Link connected.
After going through the menus to start again, it offered an entry key for the App. Usabilty problem #2. The key offered was of the form nnn-XXXX where n was a numeric digit and X a capital letter. Unfortunately, bizarrely, the hyphen was displayed, but it was not possible to enter it in the app. Fortunately it didn't seem to be necessary but how the heck a user is supposed to know that, I have no idea.
Over time, I have lost faith in Google products I'm afraid. They appear to be of good quality but if anything goes wrong, they can be a nightmare to reset. I've given up on Pixel phones because Fairphone have a much more sustainable future. Same for Chromebooks. After making a 2015 Chromebook Pixel LS last as long as possible, I now have a Framework laptop. Repairable by me, using only a screwdriver.
