I was a launch customer of the wireless flow meter and had a straight forward setup that exactly matched the above ground installation video and met all requirements for pipe length etc. The flow meter worked flawlessly during the first season.
I live in Chicago and after this first winter season upon first use in spring of the activated sprinkler system the flow meter appeared to function normally. About 1 month into the season (very little watering was done due to rain) I received my first “Low-Flow Detected” alert while out of town. Several other subsequent waterings also triggered Low-Flow alerts on various zones. Flow rates detected on zones that typically run at 5-8 gpm were 0.5-3 and the alerts grew in number (all this occurred while on vacation and I was able to confirm on security cameras that system appeared to be running normally) to where 75% of zones were triggering Low-Flow Detected alerts in seemingly random patterns.
Upon arriving home to check my system it was obvious the sprinklers were functioning normally and the alerts were false. I attempted a new calibration of the flow sensor but it failed saying the very first zone I tried had 0.0 flow (it was working normally). I then followed a troubleshooting step on Rachio.com to remove a battery from the flow meter (I had “good” battery levels and “excellent” signal strength) and then immediately replace it to reboot the flow meter. I did this and then performed a new calibration and EVERYTHING WAS FIXED. The new calibration registered consistent flow rates for all zones over my lengthy calibration period (I set system to 5 minutes a zone to be conservative but it was clear 2 minutes would have worked as well) and two full system waterings since have worked perfectly with no warnings.
Bottom line? I created this post to be easily searchable (as I did search this community for the fix and some posts had clues to what might help but nothing seemed to have my exact issue) to help other users whose flow meters suddenly and inexplicably start showing false warnings after working normally for a period of time. Key takeaways are you must REBOOT the unit by removing battery power first THEN RECALIBRATE the flow meter after the reboot. Calibration isn’t enough if the flow meter is sending wildly inaccurate readings after working normally in the first place (this all assumes proper installation.)
Not sure why this error happened in the first place after a year of normal use and hopefully the fix lasts for a long time but at least the process wasn’t a big deal.