Flow Meter Not Working - Rachio, Please Help


#1

About a week ago I posted a message about my wireless flow meter not working correctly. Nobody from Rachio responded. It was suggested by someone that I didn’t have the required 6" of straight pipe on the inlet side, and the outlet side was too close to a 90. I moved the flow meter but am still getting the same results. Here is a picture of the installation:



I’m having the same problem as before: zero flow reading on zone 1 and wildly fluctuating readings on zones 2 and 3 during calibration. The zones are operating correctly, and there are no perceptible fluctuations in flow or known leaks. I’m using city water on a meter dedicated to the irrigation system. There is a backflow preventer adjacent to the meter but very close to the ground (so there’s no room to mount the flow sensor there).

I appreciate that there may be turbulence in the flow, but if the meter is that sensitive then there should be extremely detailed instructions provided as to the proper placement of the meter. The only stated requirement is having 6" of straight pipe on the inlet side, and my installation certainly meets that requirement. The meter is only a few feet from the controller and the signal strength is 5 (excellent). Flow meter s/n is F14380626, firmware version flow-ota-combined-5.3.

I would greatly appreciate some help from someone at Rachio. One of the main reasons I spent all this money was to have protection from sky high water bills when there’s a leak or broken head.

Thank you.
Don


Crazy flow readings
One zone giving variable flow readings
#2

Something just occurred to me that would be rare, but could happen. This meter only reads to 25gpm which is plenty for the vast majority of sprinklers (average zone is 7-12gpm). I am wondering since you have 1" lines in and out and only 3 zones if you are exceeding that amount. Your installation appears to be good.
First, when you do get a random reading, is it above 20gpm? There are 2 ways that you could check to see if this is your problem. The easiest would be to turn the valve below the meter about 1/2 way. Now, this may actually introduce a problem of asymmetric flow and then the meter won’t work, but it is worth a try. If that doesn’t cause the meter to read consistently at lower flow rates, you could stick a valve on that extra 5th port you have to the right and then throttle it back until you get consistent readings. If the meter works fine everywhere up to the low 20s then you know you are probably exceeding the meter’s capability.
(NOTE: Keep in mind that if you just open the last unused cap with no valve for back pressure, you risk not having a full pipe)


#3

On one zone the readings were between approx 12 and 19 gpm. On the other zone, readings were between aporox 5 and 12 gpm. Zone 1 consistently reads 0.

I think it’s unlikely that any zone is using over 25 gpm, unless there is an underground leak, and then all three zones would have to have a leak. And if I were using over 25 gpm, wouldn’t the meter just report 25 gpm (or some other high flow/out of range indication)?

The line from the backflow valve to the shutoff is 1 1/4". It’s reduced to 1" at the 90 below the shutoff valve. There is no indication of excessive pressure or output, or anything at all unusual at any sprinkler head.

There’s only 3 zones because most of the back yard is taken up by the pool. There’s only about 6 heads on zone 2. No way that’s using 25 gpm. The other 2 zones probably have about 12 heads each.


#4

Hey @dcaton

So sorry to hear about all the trouble here! You mentioned detailed instructions - did you follow the installation instructions on our support site with the correct fittings, etc.? From the photos everything looks fine but figured I’d ask!

Would you be up for shooting a message to our support team? I would love for them to take a look and log anything weird so we can do more research. Feel free to link to this post as well - support@rachio.com

:cheers: Lo


#5

Laura the fittings are correct. I will send an email to support.


#6

MeterManSays: is it possible that the zone valves are causing turbulence, so much so that it travels through the T and around the 90 and affects the outlet of the flow sensor?

Seems odd that zone 1 (closest to the flow meter) consistently registers 0 gpm.


#7

I am going to stick with my suggestion. I have tested it and the meter does read 0 after ~25-26gpm. The only way you are going to find out if the problem is the system or the meter is to separate them. The fact that the meter does read differently on different zones tells me with a high level of confidence that the meter itself is not faulty. If you can’t do one of my valve suggestions, perhaps you can read your house meter while zone 1 is on (and nothing else)? I am starting to think the meter is an indication of what is happening in your system.


#8

I will check the city meter when I get home tonight. High gpm could explain the consistent 0 reading on zone 1 (and perhaps caused by a leak somewhere) but that doesnt explain the other two zones.

Zones 2 and 3 are never over 19 and never 0, but often have fluctuations between 2 & 8 gpm from one reading to the next. How would gpm over 25 cause those rapidly changing readings? I’d think a real fluctuation in flow like that would be evident just by observing the water coming out of the heads.


#9

MeterManSays:

Well, you were right. According to the city meter:

zone 1 - 28.5 gpm
zone 2 - 34 gpm
zone 3 - 23 gpm

I forgot that I knocked a head off of zone 2 Saturday with the lawn mower, so that explains the high reading there.

I closed the valve to the manifold about 50% and ran calibration on zones 1 and 3. Both zones ended up being calibrated at 13.3 gpm, and there was very little fluctuation in the individual readings. I guess you’re right that the flow sensor is working correctly.

So, what if I have a zone that normally runs at < 25 but develops a leak that pushes the flow > 25, like the state zone 2 is in now? A rudimentary search on flow rates says that a 1" pipe at normal city water pressure can deliver 37 gpm. The flow meter is going to report zero and the controller then does what? Is it going to shut down the zone or do nothing because it thinks there is no water flow at all? This potentially negates the benefit of measuring flow in the first place. I don’t know if this is a physical design flaw or something that can be corrected in firmware, but I don’ t know how much I trust this thing now, as far as detecting leaks goes. There ought to be a difference in how the flow meter reports zero vs. how it reports full flow beyond what it can accurately measure. At that point I don’t care how many gpms are being used, I just want it to shut off.

The second issue of course, is why is the gpm so high. Or is it? Do I have too many heads per zone, an underground leak, or is it just too high for this particular flow meter to measure but otherwise ok.

With the main valve at 50%, there’s not enough flow coming out of the heads so I can’t leave it that way. Zone 1 has about 15 heads: about 5 360°’s and the rest a combination of 90° and 180°’s. I have no idea whether 28.5 gpm is reasonable for that configuration or not. Zone 3 is roughly the same. Zone 2 has about 8 heads but it wasn’t being measured accurately either and ought to be well below 25 if not for the busted head.

The system is probably old and the few heads I pulled out to replace looked like they were connected with that old black poly pipe. I have a sinking feeling I’m going to have to redo the entire system.


#10

I’m glad we got to the bottom of this and that the flowmeter revealed what is going on in your system.

First, the flowmeter does know there is flow above ~26gpm, it just doesn’t know the value. So, as long as the software uses the information properly, it will still detect a leak. (This is up to Rachio) If you can choke it back to calibration level flow rates, you should be fine.

Second, I am an expert in the design of flowmeters, not sprinkler systems or piping. Having said that, a simple internet search reveals that the maximum recommended flow rate for schedule 40 PVC pipe seems to be quite a bit south of 37gpm for the pipe to maintain its warranty. That may only be important inside the house and probably isn’t religiously followed. But, I think that indicates that you are well above the norm. With my spigot wide open, I can only get 12gpm at my house. I’m jealous!

Good luck.


#11

Thanks for all your help.

I have a separate meter for irrigation, and it probably has a bigger feed than the meter for the house. I doubt I’m getting 35 gpm in the house. The house meter incurs sewer charges based on the amount of water used. The irrigation meter has no sewer charges.

I think I’m going to have to redo the entire system. The mains use crappy thin schedule 200 pvc and the few heads I dug up are connected with that old black poly pipe. Ugh.


#12

It appears that your system is 3/4" PVC. The 6" of pipe that need to run before the flow meter must be 1".