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Is the Flo smart water monitor still worth it 18 months later?

How smart is your smart home? Is your home smart enough to know when there's a bad leak that could cost you thousands of dollars? After 18 months with it installed, we discuss our good and bad experiences, and why installing a Flo device might be a very smart addition for your smart home.
Written by David Gewirtz, Senior Contributing Editor

Here's the Flo installed in my house.

I originally reviewed the Flo smart water monitor in 2018. Since then, I've replaced it once and added to it with a water overflow detector. My initial observations and my conclusions after 18 months are documented below.

I have had the misfortune to experience the results of two leaks inside my home. Trust me when I tell you that, if you haven't gone through this, you really have no idea how bad it can get.

The first occurred quite some time ago. I went to work in the morning, worked a long day, and came home... to my basement apartment filled with five inches of water. My cat was cowering on my bed, clearly quite freaked out.

As it turns out, one of the hoses to the washer had split. Water from the hose flooded into my apartment for hours. Later, I was told by the insurance adjuster that the top source of in-home flooding is broken washer lines, and the best way to prevent that from happening is to spend a few bucks and upgrade to metal lines. Let that be a hint to you. I've always upgraded my washer lines since that day.

To prevent that from happening again in this house, I've added the newly released Flo Smart Water Detector. More on that device below.

Also: CNET lab tests the Flo

It took more than two months for my life to go back to normal. Thankfully, most of the expense was covered by the apartment management and insurance, but I lived with huge fans running day and night trying to clear out the moisture. All my rugs had to be deep cleaned, and all my furniture had stains on the legs. All told, it cost the insurance company, the apartment manager, and me more than $4,000 to recover from the lack of a $12 metal hose.


This is what our wall looked like after discovering one small leak. Not pretty.

The second leak occurred just recently. We bought our new house and had a home inspector check it out. We were told there were no visible or known leaks.

Two weeks after the sale, I drove down to the house with my wife (we were still living in our rental house while we fixed up our fixer-upper). My wife noticed discoloration on the wall near the ceiling in a bathroom.

It turns out there was a pipe junction in the ceiling above that wall that was leaking. There was more discoloration behind the drywall. We wound up ripping out the entire wall, and with it, the vanity, to mitigate the problem. Not counting the cost of the plumber to fix the leak, the drywall repair, painting, and a vanity probably cost us a few thousand dollars, an expense we had not budgeted for.

I'm sharing these two examples in some depth to show you what can happen when your home has a leak. Keep that in mind when I discuss the Flo, a smart home device that, if installed, could have substantially reduced the damage from both these emergencies.

Getting the Flo

Serendipitously, the folks at Flo Technologies reached out to me about doing a review of Flo just about a week after we discovered the stain on the wall and were making plumbing repairs. To say I could appreciate the need for its product was an understatement.


You can see exactly what's flowing into your house in real-time.

Here's the thing: At that time, my wife and I were still living about 45 minutes away in our temporary rental home. We expected there to be at least three more months of work on the new house before it was ready for us to move in.

Although one or both of us went down there as often as our schedules would permit, there were still times when the house would be unoccupied and unobserved for days at a time. We had no idea if we would discover more leaks or problems that, left unobserved, would mushroom into new big expenses.

But, if we could put a Flo on the pipes, if something bad happened, we'd know pretty quickly, even when we were miles away from the house.

Flo picked up the cost of the $500 device and sent me one for review. It needed to be installed right at the point where water comes into the house, and it needed a power socket nearby. It cost me about $350 in licensed electrician and plumber hours to get the device installed.

If you're doing the math, getting a Flo and installing it will cost somewhere between $500 and $1,000 for most users. That seems like a lot. It is a lot.

But when you factor in the time, stress, and out-of-pocket cost for a major leak, the up-front cost is actually worth it. That's why I took you through my two experiences. I want you to understand the scope of the emergency the Flo is meant to protect you from.

How Flo works

The Flo is a smart valve. It sits at the point water enters your home and, if it detects an anomalous situation, it closes off water flow to the house. That's why it needs power. There's both a Wi-Fi client and a motor inside the unit, and both need power to operate.

Once installed, Flo takes about a week to get used to the water usage patterns in your home. A toilet flush uses a certain number of gallons quickly, then stops. Washing at a sink might use a smaller number of gallons for 3 to 5 minutes, then the water flow stops. Taking a shower uses a larger number of gallons, but after 10 to 20 minutes, that water flow stops as well. Washing clothes also uses a certain number of gallons and might run for 20 or 30 minutes.

Each of these patterns is observed and cataloged by the Flo. Flo then watches to see if anything outside one of these patterns occurs.


You don't want to see one of these, but you'd rather see one than not, if you know what I mean.

Here's how it would have worked if I had a Flo back when my apartment flooded. Once the feeder pipe to the washer broke, Flo would have detected water flow. Based on the gallons per minute, it might have even assumed a wash was running. But if the water kept flowing for 30, 40, 50, 60 minutes, Flo would suspect something was amiss.

The first thing it would have done would be to send me an alert on my phone. I would have gotten a message that said there was high water usage. At that point, I could have tapped my phone and remotely, at work, turned off the water flow into the house. If Flo sent me that alert and I did not respond, Flo would have automatically turned off water flow to the house.

Water that was still in the pipes might have leaked out the washer hose. First, if I found out there was a leak, I might have left work early to check it out. Alternatively, when I got home that night, I would have had a big puddle around the washer, not a 5-inch deep lake throughout my whole apartment.

Flo also does regular tests for small leaks. Every night, it shuts the water off for about 10 minutes. During that time, it monitors to see if there's a pressure drop. Your home's water pipes are a closed system. If the input port is closed and all the valves are closed, pressure should not drop -- unless there's a leak.

Leaks can be from a faucet not fully closed or from a pipe in the wall dripping onto drywall for weeks. The Flo can't tell you where the leak is, but it can tell you if it sees a pressure drop, which you can then investigate.

My water monitoring experience with Flo

Let's start with the last test I just described, the Flo test for tiny leaks in the system. Here's a log from a few days last week. As you can see, most nights Flo reported a successful health test. One night, it detected a small drip. And one night, the health test was interrupted.


This log contains a lot of useful information, especially when trying to determine if a leak is systemic or situational.

An interrupted health test is usually because someone in the house opens a faucet or flushes a toilet. But the small leak is the important one. If a small leak is detected each night, that's a problem. But if it's only detected once in a while, the odds are that a faucet hasn't been fully closed.

Thankfully, I've only had one high usage alert, and that was while painters were at the house. Funny story. I had installed the Flo, but still wasn't living in the house. As such, our water usage was negligible. There might have been a toilet flush once every day or so, but that's about it.

Suddenly, the painters were there, and they were using a lot of water to clean up. I got a high water alert and immediately called the contractor. "Hey," I said. "Is there any chance you started to use a lot of water down there?"

"Uh, yeah," replied the painter. "Why?" A second or two passed. "Wait," he exclaimed (for real, his voice went up a whole octave). "How do you know?"

I explained the Flo. While I was excited that the system worked, it was clear that the idea I knew what was happening at a water flow level from across the state discomfited my contractor. I think he's been suspicious of my gadgets ever since.

One more real-world example

As I said, we're living in a fixer-upper. Fixer-uppers are often great investments, but there are days.

A month or so after I got the Flo, the rainy season hit in full force and we discovered a leak coming from the ceiling in our hall. We had to break open some of the ceiling and we found both a water pipe and boards from the roof. The question was: was it the pipe or was it the roof?

We were pretty sure we could eliminate the pipe because the previous night's Flo health test hadn't reported a leak. To be sure, I manually initiated a health test run, and ten minutes later, we had our answer. It was not the pipe that was leaking.

We were able to quickly eliminate one possible source of the leak. While we still had a roof to fix, the Flo was able, at least, to tell us it wasn't the fault of the pipe.

Some minor complaints

Setting up the Flo was a pain. You're supposed to pre-bind it to your Wi-Fi network before the plumber shows up. I did that, but once installed, it lost that connection, and I had to spend almost an hour fiddling with the unit and restarting it before I got it to bind with my router. That cost me an hour in plumber fees.

Once it was finally connected, it worked flawlessly for about six months, then it died. Kaput. Zilch. Fortunately, it didn't die in the middle of a water pressure test, so we were still able to use city water. Had it died with the flow constrictor closed, we would have needed to use a special hex wrench to open it back up.

I contacted the company (this was before they were acquired by Moen), and it sent me a new device. However, not wanting to incur more plumbing service fees, I let the replacement device sit on my shelf for about half a year. Then, I had another plumbing project that needed attention, so while the plumber was here, I asked him to replace the dead device with the new one. He did, and since all the prep work had been done for the previous device, the installation of this new one didn't cost nearly as much as the original install.

The new device does the smart water check in seconds instead of minutes. Since we installed it, it's reported on our water regularly, and once again, we've got peace of mind.

I'm also not thrilled with how the power connector goes into the Flo unit itself. There's a gasket that's intended to prevent water from getting into the power connector, but it tends to push the connector out of the small socket.

A much better design would have been a positive link or lock once the power connection was made into the Flo. Again, it's worked since I set it up, but it could be a bit better.

The Smart Water Detector

Moen has added a line extension to its Flo product that makes a lot of sense. The Smart Water Detector is a little puck that sits where pooling water would gather in the event of a leak. When my 18-year-old fridge died last fall, I bought a Samsung Smart Things leak detector and placed it under the new fridge. Because the plastic water line goes into the wall, we couldn't replace it with a metal one. That plastic line was at least as old as the old fridge, so we decided a pro-active monitoring solution would be a good idea.

This was before Flo introduced its water detector. While the Samsung device will post alerts, the Flo Smart Water detector goes one step further. If it detects a leak on the floor, it automatically shuts off the water using the Flo. I placed the unit Flo sent me under the washing machine, in case that decides to flood.

This gives Flo multiple points of leak monitoring. The device can sense water pressure changes at the main junction. But by using the leak detectors on the ground, it can also sense leaks from around the house and shut them down, possibly preventing the kind of disaster I had with my washing machines back in the day.

Yes, probably. The cost of water damage is so high that if you're even slightly concerned about making sure you don't live through an inside flood or leak that could cause mold or other organic substances, it's worth getting. It also detects high water pressure and freezing water temperatures, so you have a much better chance of preventing bursts due to freezing pipes.

Back when we were in Florida, there was a lot of what we called "snowbirds," folks who lived in the north through the summer months and moved down to Florida for the winter months. If you're someone who migrates between homes and, for whatever reason, can't shut off mains water at the house you're not at, a Flo might prove essential.

Likewise, if you're someone who travels a lot, being able to monitor water usage from anywhere in the world is a big win. I had a major disaster in my apartment, and that was from water flow while I was at the office, just my normal commute away from home. Back in those days, I traveled a lot, and when I think about how bad things might have gotten if the water kept running for days, it gives me the chills.

Yes, the Flo is pretty expensive. It's also not able to pinpoint where a water problem occurs, just that there is one inside your home.

Think about this: Zillow says the median home value in the US is $221,000. The site CostHelper says that it can cost from $5,000 to a whopping $70,000 to clean up damage from a water leak. Is it worth spending $500 (plus labor) to protect such a huge investment while at the same time preventing such huge costs?

In my mind, after living through two very costly water damage situations (which, still, were at the low end of the overall cost spectrum), and then, with the Flo, being able to quickly eliminate and positively identify a roof leak, my answer is "yes." It is worth the initial expense. That's because the cost of damage ranges from simply daunting to truly horrifying. Plus the stress. Don't forget the stress.

Of course, if the Flo fails, as mine did, you might only think you have water monitoring. When our first Flo stopped working, the app did not alert me. We probably went days to weeks without active water monitoring, and it was only when my wife pointed out she hadn't heard the sound of the valve closing during test time that we finally realized it was dead. The Flo rep wouldn't tell me if these failures were common or if it was simply growing pains since I was an early adopter. That said, I'm far happier with the new replacement Flo installed than I was during the intervening time that we didn't have it watching over us.

You can follow my day-to-day project updates on social media. Be sure to follow me on Twitter at @DavidGewirtz, on Facebook at Facebook.com/DavidGewirtz, on Instagram at Instagram.com/DavidGewirtz, and on YouTube at YouTube.com/DavidGewirtzTV.

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