How does the flow sensor work for Gen2?


This would be aggregated into your total water usage, and not associated to a zone or schedule.



Is one flow sensor recommended over others?

Is one better with low flow?

My pipe is 1/2", and my pressure is between 7 - 15 psi (micro irrigation)

It will be installed indoors, should it be brass rather than PVC?



It looks like the TFS-050 is the only one that’s 1/2". I believe this should be fine, but you’ll need fittings to connect to your copper piping.


I see that Badger has some 1/2" brass, but Rachio does not seem to support brass or 1/2" from them.


@Chapin, we’ll look into this sensor to see if we could support it. How soon are you planning on installing a flow sensor?


Hi Chapin,

It looks like this one works electrically same as the others that we support. We should definitely have a brass flow sensor on our list. The 250BR series seems perfect. Thanks for pointing this out. We’ll take this back to the team and see if we can get it added to the support list.

  • Brad


Excellent, thank you.

I’ll likely end up with PVC. The brass looks to be 3 times the cost, and it seems to me the PVC is expensive.

I’ve got some other questions re flow sensor. Should I post here or start a new thread?


Probably fine to post here.



First, a couple of questions.

How accurate is the flow sensor? Does it overrule the the flow math based on soil and emitter type?

Do different pipe size flow sensors measure and report flow differently?

Currently, my estimated water usage is way off. Rachio is unaware of my low pressure micro-irrigation system and low pressure drip emitters. Will the flow sensor accommodate these? I’ve been unable to set plant type, sprinkler type, and soil type. Most of my zones (8 of 10 so far) are containers with kitchen herbs or ornamental annuals and perennials or straw bales with vegetables. My sprinklers are primarily 1/4" dripline or 1/4" soaker hose. There aren’t options for my soil and sprinklers types.

I’ve got two PRVs that reduce my house pressure (80psi) to 10 - 15 psi. Does it matter where I install the flow sensor, on the 80 psi side or the low pressure 10-15psi side? (the 80psi is far more convienent for me.) There is a back flow preventer with the two PRVs.

Sorry for the sloppy questions, I think I should start a new topic about micro/low pressure drip irrigation and straw bale and or container gardening.


Thanks Brad.

I did find one of these (brass & 1/2") online for less than twice the price of the Toro 1/2" PVC.

Would this be the one to order, 250BR0505-1211 with “Standard Electronics” (“IR” Irrigation is for below grade installations), EPDM O-Ring (Standard), Tungsten Carbide Shaft (Standard), Nylon Impeller (Standard), and UHMWPE Bearing (Standard). I presume that they will all perform very similarly.


@Chapin, I believe accuracy will be on the flow sensor manufacturer to estimate. Once we support flow in the app, the Rachio controller will take the data sent from the flow sensor and will replace the predicted usage calculations on a per zone basis. Similar to a rain sensor, if the flow sensor is sending bad data, bad data will be reported in the app.

I’d recommend reviewing this FAQ from CST – it does a great job detailing installation questions.

Do you know the GPM coming from your dripline and soaker hose? The lower limit of the flow range is an important consideration when selecting a flow meter. Low flow applicators (drip, etc) make it easy to reduce irrigation zone flow rates below minimum velocity ranges required by the flow sensor – or in other words, the velocity in the pipeline is so low that it can’t be detected; there is not enough energy in the water to turn the impeller and generate a flow signal.

Will defer to @alcornb for this question :wink:


so what affordable flow sensor do people recommend? I installed my Gen 2 yesterday before my seasonal startup, what are people buying?


I bought a toro, saw rachio’s ee guy make reference to cst, have purchased


so is that CST one supported?



so am I understanding this right- this is all I need?

this just looks like the receptacle, not the actual sensor?


Rachio Support:

You had listed the Badger Meter Series 228PV (15/20 either 1.5" or 2") as compatible to the Rachio Gen2. This is a Wireless Water Flow Sensor:

In the Wireless receiver end, it has a Pulse Output. Do these connect to the Rachio SC and either S1 or S2? So a wireless system is compatible?


Here are the specifics on pulse output for the Receiver on the Badger Meter 228PV15 Wireless receiver. I just want to make sure this product is supported before purchasing unit.


Hi Juanjg115,

That sensor output of that system does work with our controller, but there are some restrictions to keep in mind.

  1. You need to make sure you buy the model that does “Frequency Output”. The part number would be something like “228PVxxx U xxxx”. That distinction is important as our controller does not support the “Pulse” output the “W Model” Electronics provides. We expect a frequency signal, paired with the correct K and Offset values to derive the flow.

  2. You’ll need a seperate power supply for it, as it does not come with one and our controller only has a 34V DC line.

  3. Make sure you get the antenna pack that comes with it.

Hope that helps!



Thanks Devin… one more question. My Water Meter is 3/4" and so is the sprinkler piping. But the smallest size of the badger flow sensor is 1.5". Is there any issue with using an adapter on each end to adapt to the smaller size piping I have?