Flow meter not working properly


Having similar problem as others have had; wildly inconsistent and sometimes zero readings.

On zone 1, it almost always tells me that no flow has been detected during calibration. Zones 2 and 3 often show drastically different readings from one measurement to the next during calibration.

I’ve watched the water meter when running all three zones and water usage appears to be roughly the same on all zones. Pressure at all heads seems fine and there are no (known) leaks.

I’ve seen mention of turbulence in the lines causing problems. Here’s a picture of my installation. I can’t mount the meter near the backflow valve because it isn’t high enough off the ground.


Thank you!


Just thought of something… To the right of the three valves, there’s another T and then a 90. Both have threaded male adapters, where two additional valves could be mounted if I need more zones in the future. For now they are capped off.

I screwed the caps on tight before turning on the water for the first time, so there may very well be air trapped in the line where valves 4 and 5 would be mounted.

Could this be causing problems with the flow meter? If there is in fact air in there, could it be causing pressure to fluctuate or turbulence?

I’ll have to check tomorrow night, but is this even possible that trapped air could cause erratic flow readings?



Although hard to tell from the small picture alone, it appears that you do not have 6" of straight 1" run upstream of the meter. Even if that is the required 1" pipe (appears to be 3/4") on inlet side, the valve appears to be closer than 6".


It is all 1" pipe. Why would the valve matter? In it’s open position, there is no obstruction or restriction.


Ok, the air in the line theory didn’t pan out. If there was any air in the lines, there isn’t anymore but the problem remains. During calibration, two of the zones report no flow at all. The remaining zone fluctuates between 12 and 19 gpm and there’s no way that’s correct.

Can someone from Rachio please take a look at my installation and let me know if there’s something wrong? MeterMan is correct that there isn’t 6" of pipe on the inlet side, but is the presence of the valve really causing the sensor to malfunction? It’s a standard ball valve and presents little to no obstruction when in the open position.

What about the sensor outlet side? There’s a 90 that’s pretty close. Could that be causing problems? Or do I just have a bad sensor? Before I cut off the shark couplings and move things around I’d like to hear from Rachio tech support.



Many valves have a smaller ID than the pipe size of their connections. Any restriction of flow by smaller diameter that close to the meter will cause turbulence. Although altering that would likely fix the problem, the other problem is how close you have not just one 90 degree, but another within a couple inches. I am betting that the zone that doesn’t read flow at all is the leftmost zone closest to the meter. You can usually get away with one 90 degree close to an outlet of a vortex meter, but having essentially a manifold with multiple Ts right after is iffy at best.

If you reinstall it to get the valve farther away, I would suggest also giving yourself more straight run after the valve before the 90 as well.


I bought this particular valve because the opening appeared to be the same size as the 1" pipe interior but I can’t say for certain. In any case, I guess I’ll move it and also reposition the sensor so it’s further away from the manifold 90. Hopefully that will fix the problem. I had no idea the placement of the sensor was so sensitive.


Virtually all flowmeter technologies require a consistent flow profile (non turbulent) to be accurate. The PD meter for your house does not, but it has a huge pressure drop and its accuracy will degrade continually over time as the moving parts wear out. (fortunately for consumers, it undercounts as it wears out)