Flo Smart Water Monitor & Shutoff review: To protect and to save

Best Prices Today: Flo Smart Water Monitor & Shutoff

I reviewed the first-generation of this product, then branded as the Flo by Moen smart water valve, in early 2021. I later replaced it with the Phyn Plus (and in late 2022, with the 2^nd-generation Phyn Plus), which I found to be even better. Today, Moen’s revamped product has leapfrogged the Phyn Plus.

If you’re unfamiliar with this class of smart home device, it fits in your incoming water supply line—usually replacing your existing shut-off valve—where it monitors a host of factors related to your water supply: leaks, first and foremost, but also household water consumption; water pressure and temperature, and more. If it detects a leak in your water system—be it from a burst pipe, a running toilet, a leaky faucet, or what have you—it can automatically shut off your water supply to prevent catastrophic damage.

As we outlined in a recent story, smart water shut-off valves like the Moen and Phyn products can also earn you a discount on your homeowner’s or renter’s insurance, and you can print a letter certifying your ownership of Moen’s device right from the company’s app. Insurance companies reward this kind of risk mitigation, because claims from water damage are more common than claims from fire damage.

If the Flo Smart Water Monitor & Shutoff detects any anomalies in your water supply line, it will set in motion a sequence of events that will automatically turn your water supply off to prevent catastrophic water damage.

One of my criticisms of the first-generation Flo by Moen was that you needed to sign up for an ongoing subscription to get the full value out of the product. That’s no longer the case. You can sign up for an optional FloProtect subscription ($5 per month) under which Moen will pay up to $5,000 of your homeowner’s insurance deductible should you need to file a water-damage claim, and the sub will also extend the valve’s 1-year warranty to 5 years. But you won’t lose out on any of the product’s features or functions if you don’t sign up.

Design and features

There are three models of the Flo Smart Water Monitor & Shutoff for copper, PEX, and PVC water pipes in the three most common sizes: 3/4-, 1-, and 1-1/4-inches, priced at $500, $550, and $800 respectively. Installing one can be a DIY project, but Moen strongly recommends hiring a professional plumber for the job. Moen hired a plumber to install the device on my 3/4-inch PEX water supply line, downline from a pressure-reducing valve I had installed when the 2^nd-generation Phyn Plus I reviewed earlier identified dangerously high water pressure coming from my city water supply.

If you’re wondering what a PEX water line is doing in a 134-year-old house, it’s because I had it installed shortly after I moved in. The previous owner had replaced whatever was there originally—cast iron or galvanized steel, perhaps—with PVC, but that material is relatively brittle and prone to bursting if the water in the line freezes. Having experienced catastrophic water damage when a much stronger copper water line burst in my previous home, I didn’t want to take any chances.

Smart water valves rely on AC power to operate, so you’ll need to make sure there’s an outlet nearby that you can plug the adapter into. As I recommended for the Phyn Plus, you might want to plug the Flo into an uninterruptible power supply to ensure it continues to operate in the event of a power outage. You will receive a push notification if the valve drops off your network for any reason.

When the plumber installed the unit in the crawlspace of my basement—yeah, my 1890 bungalow has a partial basement and a partial crawlspace—he found that the supplied 10-foot power cord was about 18 inches short of reaching the outlet, so he plugged the power adapter into a 50-foot extension cord he had in his truck. I didn’t discover this until several months later. I know that Moen offers its own purpose-built 25-foot extension cable for about $14, but when I mentioned to the Moen folks what the plumber had done, they told me it was fine and that I didn’t need theirs. So, I replaced the plumber’s cord with a much shorter one I had laying around and gained a new extension cord for my outdoor power-tool needs.

In addition to having a nearby AC outlet, you’ll need to connect the Flo Smart Water Monitor & Shutoff to your Wi-Fi network, and it will only connect to 2.4GHz networks. I use the Eero 6 dual-band mesh Wi-Fi router integrated into a Ring Alarm Pro for my Wi-Fi router, and this single-band requirement gave me trouble during my initial setup—I just couldn’t get the Flo to connect to the router. In the end, I used the Eero’s ability to temporarily pause its 5GHz network, so that its 2.4GHz is the only one available just long enough for you to onboard your 2.4GHz device. That did the trick. It’s worthing noting here that the valve will continue to monitor your water line if it temporarily loses its connection to your network, and it can still shut its valve in the event of an emergency.

One of my other criticisms of Moen’s original smart valve was that Moen didn’t offer remote sensors that could detect water collecting where it shouldn’t be and then trigger the valve to shut off. The company has since remedied that with its Moen Smart Leak Detector. You place these battery-powered sensors next to plumbing fixtures like sinks and toilets and appliances like water heaters, washing machines, and dishwashers. Once you’ve connected them to your home network, they’ll alert you if they detect the presence of water. But they can also be configured to send a command to the Flo Smart Water Monitor & Shutoff to close your main water supply if they detect a leak.

Using the Moen app

Once the smart valve is installed, you’ll need to set up Moen’s app on your smartphone. And this leads to my biggest criticism of the product: There are actually two apps. I tested the valve with the Moen app that incorporates other Moen products into the Moen Water Network. That’s great if you have other Moen plumbing products that are part of that network, such as Moen’s smart faucet (we have a review of the second-gen model in the works), Moen’s smart sprinkler controller, which we reviewed in the summer of 2023, and the Moen Sump Pump Monitor. But if you also want to use Moen’s excellent Smart Leak Detector, which can trigger the valve to close if it detects water, you must add that device using an entirely different app: the Moen Flo app.

A large panel at the top of the app informs you of the status of your smart water devices, hopefully with a green light and a message reading “Everything is OK.” A box below that lets you put all of your Moen smart controls in one of three modes: Home, for everyday water use, during which you’ll get alerts if anything goes wrong; Sleep, if you know you’ll be using an abnormally high amount of water, such as to fill a swimming pool, and you don’t want alerts or emergency shut-offs; and Away, for when you’ll be away from home for a significant amount of time. In this last mode, the devices will respond more quickly to any water-usage anomalies to reduce the risk of water damage.

A button in the next box down lets you turn the smart valve on and off with a touch. This is very convenient if you or a plumber will be working on your water line. Should you ever lose power and need to turn off the valve, Moen provides an Allen wrench for the task. Lastly, there’s a “winterize” mode that you can set if you’ll be away from home and you’re worried that your pipes might freeze. This feature requires you to also own a Moen smart faucet. Winterizing shuts the valve but opens the faucet to drain any standing water from the line, reducing the pressure on the pipe. Curiously, your whole-home controls need to be in Home mode for this to work.

Tapping on an in-app illustration of the smart valve takes you to a new screen specifically for that device. The first tab here provides a water pressure reading; water flow rate, if any fixtures or faucets are actively releasing water; and the ambient temperature. The next window shows trends for these same readings in real time, over the last 24 hours, and over the last seven days. You’ll see graphs for average flow rates, pressure readings, and ambient temperature.

The Flo Smart Monitor & Shutoff will perform an automatic microleak test at least daily, during which it will shut off your water supply and then look for any drop in pressure that would indicate there’s a leak somewhere in your freshwater plumbing. You can also run this test on demand, and you can program the device to perform multiple tests each day. You won’t get a report on the results of automatic tests unless they’re abnormal, but you will get an in-app message and a report via email for any manual tests you run.

The next tab in the app reports your home’s water consumption for the current day, for the past week, and for the month to date, measuring it against a goal that you set. The default goal is 80 to 100 gallons of water per person per day, and you can use an in-app calculator to compute your goal. A bar chart at the bottom of the app tracks your consumption by the hour for the daily report and by the day for the weekly report; the monthly report is just a number.

Scroll down on this page of the app and you’ll see a consumption report broken down by fixture. You can inform the app which type of home you live in (single-family home, apartment, condo, or “other”); whether it’s your primary residence, a vacation home, or you rent it out; the size of your home (in square feet); the number of people in your household; how many floors you home has; the number of bathrooms; and the number and type of water-related fixtures and appliances in the home (bathtub, shower, washing machine, refrigerator with icemaker, and so on).

Moen has an algorithm that is supposedly able to distinguish between water flowing from a showerhead and a toilet refilling after a flush. It’s also supposed to be able to identify appliances, pools, hot tubs, faucets, hoses, and more. But I wouldn’t put a lot of faith in its accuracy. Living in the Pacific Northwest, I haven’t needed to irrigate my garden since the end of last summer, yet Moen’s app reports my irrigation system as having dispensed 201.7 gallons of water during 10 events over the last seven days.

But if you’re like me, you’ll pay attention to these reports for the first couple of weeks post-installation and then all but forget they exist—unless you want to illustrate to your teenager the real-world impact of his 30-minute showers.

Automatic operations

With any luck, you’ll find you rarely need to interact with Moen’s app once you’ve set it up, as the smart valve operates on its own 95 percent of the time. If the valve detects an anomaly, it will set in motion a sequence of events that will automatically turn your water supply off to prevent catastrophic water damage, but not before warning you with a push notification and a robocall from “Vince,” who will ask if you want your water turn off or to be left on. If you miss these notifications and your water ends up getting shut off unnecessarily, you can turn it back on with a push of a button in the app.

I did experience a few false positives in the early days after I had the valve installed, but that’s to be expected as the algorithm needs to learn your household’s patterns. One day last fall. my wife and I were in the garden until the early afternoon, and we didn’t shower until we came in (we typically shower first-thing in the morning).

My wife went first, and I got in after she’d finished—and without turning the water off. Moen’s algorithm decided it was seeing too much water use in the middle of the day and assumed something was amiss. Having left our phones in the basement, we missed the warning notifications and the robocall, so my shower was interrupted about halfway through as our water supply was turned off. Fortunately for me, my wife was already dressed and went into the basement, retrieved her phone, and turned the water back on. If you find you’re getting too many notifications for regular water-use events, such as irrigation sessions, you can program manual overrides that will ignore them.

Should you buy a Flo Smart Water Monitor & Shutoff?

Smart water valves that can mitigate water damage from burst pipes are a wise investment—that’s why insurance companies provide incentives for installing one. If you took my advice and installed a Phyn Plus, you made a good decision and there’s no reason to think you need to replace it with Moen’s product. If you took my earlier advice and bought Moen’s first-generation product, the same reasoning applies: You are sufficiently protected.

If you don’t have a smart water valve, and you want to track your water use and protect your home from catastrophic water damage from burst pipes, Moen’s Flo Smart Water Monitor & Shutoff is the product to buy. That goes double if you already own or plan to purchase other plumbing devices in Moen’s Smart Water Network.

Best Prices Today: Flo Smart Water Monitor & Shutoff