Just want to add this post combined with another one on DNS_FAILURE helped me with my issue.
I’ve had Rachio 3 running for about a year. However just a few days ago I noticed the Rachio went offline. Tried many different reset on router/modem/Rachio over a span of few days and nothing worked. Always end up stuck at the “3rd stage” light with a red light that flashes occasionally.
Long story short, my Spectrum Internet DNS server appears to no like something the Rachio 3 is looking up causing the Rachio 3 to stay offlined. I reconfigured my router to use Google’s DNS server (8.8.8.8) instead of my Internet providers and that solved the issue.
Details:
Using this page’s info which shows how one can directly talk to the Rachio hardware via wifi, I found out the issue is with DNS_FAILURE. Another thread (Rachio 3 not connecting to WiFi - DNS - #5 by ProWater), shows possible server Rachio 3 uses - but all of them resolved fine for me.
Not sure if Rachio added something new recently, but since it is a DNS failure, I decided to just change my router’s DNS config to use Google’s DNS server instead of Spectrum’s and that fixed the problem.
Costco’s 12-zone Rachio 3. Spectrum cabinet Internet in San Diego.
IMO, it would be useful if Rachio can add these level of details to the app under some advanced debug info instead of having users dig this up via search and use command line to communication directly with the hardware.