Rachio Gen 3 (Cannot update firmware) WIFI IOS 26.3 unknown error

My controller got disconected due to power outages and would not come online(it had previously worked fine). Apparently it needed a firmware update but could not successfully connect to WiFi to download it. It “saw” the network and “appeared” to connect but then would fail with an “unexpected IOS” error.

I since realized that (It was a catch-22 since the new firmware would be needed to fix the problem) and all other trouble shooting tips did not work:

  1. Hard reboot and RESET WIFI settings

  2. Switch to 2.4 GHZ including Router reboot and improving signal strength

  3. Use Apple devices with Older versions of Apple IOS

The only thing that worked was to use an Android phone . download the Rachio App (from Google Play) which would connect and complete the firmware update. After which the IOS devices worked !