Best smart automatic water shutoff valves

Flo measures flow and pressure in the main line, so it can shut off for a burst anywhere in the house.^{2 5} Moen says a nightly test can catch leaks as small as one drop per minute.⁶ Treat that as a best case. In one home's 2021 trial, the test caught a drip every 6.5 seconds and missed one every 52 seconds, and a homeowner blog reports a steady tub drip going unflagged for days.^{7 8} Even so, the test found a running toilet and a dripping faucet for a five-year owner, and in the 2021 trial it flagged smaller leaks automatically than Phyn did.^{5 7}

Its weak spot is the turbine, the small plastic wheel that measures flow. One landlord found a unit reading zero while guests were using water. The nightly test kept running, but the valve could no longer respond to a burst, and no alert went out.⁹ Commenters on that owner's videos raise this often, and a second channel and a homeowner blog also report turbine trouble.^{7 8 9} Moen sent a free replacement part, and the swap is a simple job.⁹ Check your usage graph every month to confirm it isn't stuck at zero.

Owners are split. The five-year owner likes it, but had to set a daytime override because laundry plus a long shower looked like a burst, and has to power-cycle it when it drops Wi-Fi.⁵ A plumber on one trade forum reports no trouble with Moen units, while another poster there says contractors have broken its plastic union nut.^{10 11}

Moen dropped its feature subscription in 2020, so core protection needs no plan.^{12 13} The optional FloProtect plan extends the one-year warranty to five years and adds conditional reimbursement of your insurance deductible, but you must start it in the first year and keep it up without a lapse.^{14 15}

The shutoff itself has no recall, but its old 920-001 battery backup was recalled on April 13, 2023 because it can overheat, with three reports of fires.¹⁶ If you have one, unplug it immediately, stop using it, and contact Moen for disposal instructions and a refund. Don't put it in the trash or in a store's battery recycling box.¹⁶ Don't buy a used one. The current backup is the 920-008, and it runs the unit for up to 4 hours.¹

Phyn uses an ultrasonic sensor to measure flow, so there's no turbine to fail.^{7 17} A 2019 test at Utah State's water lab backs up the meter, on earlier Phyn Plus units. On a weighed test bench at 0.25 gallons per minute, where 100 percent is a perfect reading, three Phyn units read 97.19 to 101.04 percent. Three Flo units read 0, 87.57 and 123.05 percent. The unit that read 0 was a first-generation model, and Flo says it later improved low-flow metering.¹⁸ At 2 and 15 gallons per minute, both brands stayed within about 3 percent, so either meter is good enough for a burst.¹⁸ The test measured metering and not leak catching, so buy Phyn on this result only if you want accurate usage data at trickle rates.

Power is the bigger trade-off. Phyn has no battery backup. When the power fails, it holds its last position and can't close, so you'd have to close it by hand with the included tool.^{17 19} If outages are common where you live, choose Flo.

Expect a slow start. Auto Shutoff stays off until Phyn has logged 700 water events, or 1,000 in homes with fixtures such as irrigation or a water softener, and it becomes available after 21 days at the latest.²⁰ After that, how fast it closes depends on your home's usage history and your alert settings.

Phyn Plus is now sold as Phyn Protect. Phyn says you get the same monitoring and leak protection with a new name and updated look, though its FAQ also mentions updated product specifications.^{17 21} The lab test and owner reports here all come from Plus units, so read them as a guide to the Protect and not as proof. A store listing for Phyn Plus (2nd Gen) is the older label. The warranty is listed at two years, but Phyn says terms depend on the product, so confirm them before you order.^{14 19 21}

Adapters aren't included.¹⁷ Cord length needs checking too. Phyn's product page asks for an outlet within 12 feet, its Protect FAQ lists a 4.2 foot outdoor-rated cable, and its help page gives 11 feet for the 2nd Gen Plus. The cord can't be extended, so measure the one in the box before anyone cuts pipe.^{14 17 21 22}

The owner record is thin. The No More Leaks channel ran Phyn units for years and praises its plumbing check logs, and one forum poster calls it a very good system.^{7 11}

This kit is a different kind of product. A motorized robot clamps onto your existing lever valve and closes it when a paired sensor reports water.^{3 4} It has no flow meter, so a leak where no sensor sits goes unnoticed, and you get no usage history or nightly leak check.^{3 4} Buy it to protect appliances, and put a sensor everywhere water could escape.

Everything depends on your valve. YoLink's manual says the robot can't correct mechanical problems in the ball valve, and a motor may stall on a stiff one.^{23 24}

Check the box before you count on it in an outage. A third-party description of YoLink's Valve Controller 2 says it runs on AA batteries through a power cut, and that a directly paired sensor can close the valve with no internet.⁴ This kit's part number points to a different controller, the X3, so confirm which controller you're getting and how many sensors come with it.

It costs noticeably less than an inline valve, even before the plumber's bill.³ Owner reports are few. On one forum, one owner reports more than four years on a Bulldog robot and another over a year on YoLink's high-torque robot, with no failures.²⁵