Flow sensor data is drastically off

Toro flow sensor is reading around 30 gpm. Says I’ve used 11,000 gallons in last 2 days waters 3 zones that all are drip line only. Each tree is getting 1 gallon every 10 minutes. 8 trees per zone. I intentionally bought the Toro supported model hoping to avoid this. I thought the calibration would measure it. I’m trying to understand where I adjust the flow rate the controller sees from the flow sensor.

@AnthonyPuca I verified you are on the lastest firmware. I’ll have our engineering team review your account in the morning.


I opened a ticket last night also with screenshots. One valve that has no openings yet, for future garden, showed billions of gallons being used just for the calibration. I had a rain sensor sharing the sc port, I unplugged the rain sensor last night so now it’s just the flow sensor and now the numbers are around 260 gallons per zone used for calibration. I know for a fact that each zone is putting out 7-8 gpm from me timing and measuring


@AnthonyPuca Looks like the flow sensor is configured as CST FSI-T10 not a Toro in our system. It has 0.32 for kFactor and 0.2 for offset. Can you please verify the make and model of your flow sensor? Once you do can you recalibrate without rain sensor and then with rain sensor plugged in? I would like to check the readings once we know we have proper configuration for both cases.


Sorry, my bad, I have the CST flow sensor, not the Toro. You’ll notice from the pic that I have the CST FSI-T10 flow sensor paperwork and have that selected in the app, and I’m getting these crazy readouts. 2 billion gallons used calibrating a line that has no flow.

this happened to me last year with the same sensor except sometimes it would read really high on some runs and very low on others. it finally just stopped working altogether. i sent these poor guys on a long wild goose chase, it ended up being the sensor that went bad over the winter.

im not sure if they had a bad production run or if the sensor doesnt like going to 4 degrees. this year i brought mine in for the winter and its working well this season.

Brand new sensor, never been used, consistent across all zones too. I did a catch cup measurement and know exactly how much I’m watering, I wish there was a way in the app to put in a multiplier or divider to make it read accurately in-app.

@AnthonyPuca I do not see an image of paperwork. Please verify that kValue and offset that we have are the same as in flow sensor spec.

Paperwork pics attached in helpdesk ticket. No way to attach pics in your webpage that I can find. The paperwork says to use K=0.322 and Offset = 0.20. Don’t see where in app to do this. Do you do it per zone? Flow sensor selection and calibration are only options for the accessory.

Local irrigation company I bought some supplies from last weekend warned me about support issues like this. Swapping out sprinkler controller is easier than flow sensor that’s in-line.

Re-ran calibrations again without rain sensor, 281, 280, 281, 277 GPM is reported.

@AnthonyPuca Those are the settings that we have saved for that flow sensor selection. We assign those whenever you pick make and model of the sensor. So looks like those are correct. We are seeing very high frequencies from flow sensor


flow_gpm = (f + Offset)*kValue

if you look at the sensor on https://www.creativesensortechnology.com/pvc-flow-sensors its pretty easy to swap it out, you unscrew the old and rescrew the new (turn off the water though).

you have pic of your flow sensor?

That’s the sensor I have, but it’s not an “easy” swap as it is in-line between vacuum breaker and the manifold.


@theflexdude I re-ran it with the rain sensor plugged in again. 283, 283, 283, 279 GPM. I’ve noticed that since I reversed the wires for the flow sensor, I’m not up in the 2 hundreds vs. the initial lower ranges in the twenties. I now have the Red wire from the flow sensor in the S1 and the Black in the SC. I found a pic on your site that showed it that way. I had them reversed when it was the lower counts. Going to swap and retry. Is rebooting the Rachio required for these kinds of changes? I’m running about 150’-200’ from manifold to controller. Had to get 250’ roll and have some left. Sensor paperwork says it is good for up to 2000’.

@theflexdude you said high frequencies. Could too much pressure be causing a “frequency” issue? There is a hum and the cable does route in the garage behind my refrigerator.

@AnthonyPuca Hmm, may need to ask CST guys this question and see what could cause these abnormal readings. And black wire should go to common. Maybe something is reversed in the flow sensor?

the sensor is humming? as in air is in the pipe?

Popping popcorn for this one. Very interesting scenario. Staying tuned.