Rachio flow meter Low-Flow Detected alerts and fix

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.

Happy watering.


Thank you for your information, very helpful to have for reference.
Please update us if it goes out of calibration like that again.

Debating one myself.

Thanks for the post @boldblue737. I just started receiving this error and immediately found your post. I have the exact same scenario. The system was running fine before, and there doesn’t appear to be a true problem with the irrigation. It’s reporting 0.4GPM flow with a 3.9GPM baseline. I’m pretty sure that would be really obvious if true.

I’ll try to change out the batteries and re-calibrate per your experience. Thanks again!

I have had a similar problem. For me there are two problems. The first is that the flow meter begins permitting less water through to the valves, which leads to low flow alerts. The second is clearing those alerts doesn’t work without the reset named above.

The first problem, for me, was cleared by repeatedly flushing the flow meter with unobstructed down flow. In my case I took out the downstream filter and gush water through. Even though the filter showed clear, there has been several instances where brown water came through at first flush. Probably should have put the filter on the other side, alas. However at least for now, this solution has brought the flow back to life quite nicely. Some circuits were only getting a gallon whereas post flush they are getting 6 gallons.