When you’re away
Automatic Water Shutoffs & Leak Detection
Understand how Moen Flo and sensor-triggered systems detect leaks, close the water supply and fit into your home.
Automatic water protection
Two ways to
spot a leak.
A motorized valve can stop incoming water when its system detects a leak—even while you are away. The detection method determines what the system watches.
Measures water moving through the home
Moen Flo
Flo installs in the main water line and monitors flow, pressure and temperature. It learns usage patterns, runs leak checks and can close its built-in valve when it detects a potential leak. The app also lets you see water use and close the valve remotely.
Installation includes the correct pipe size, a nearby power supply and Wi-Fi setup. We locate it after the manual shutoff and pressure regulator so the home’s intended water use passes through it.
Read more: Moen: Flo water monitoring and automatic shutoff ↗ · Moen: Flo installation guide ↗
Reacts to water where a sensor is placed
Sensor-triggered shutoffs
Systems such as the Resideo L5 can close a motorized main valve when a connected cable or compatible paired detector senses a leak. Sensors can sit near a washer, water heater or other likely wet spot.
Sensor placement determines where the system can detect escaped water. We test the valve, the sensor connection and the alert setup together, then show you how to reopen or operate the valve manually.
Start with the water you want protected.
The valve controls the branches downstream of it. We locate the house main, pressure regulator, outdoor branches and treatment equipment before choosing its position. A sensor beside the washer must sit where a leak will reach it; a flow monitor needs to recognize the household’s normal water use.
Closing the valve stops incoming water. A leaking tank or pipe can still release the water it already holds.
Living with an automatic shutoff.
What happens when the Wi-Fi goes out?
A powered Moen Flo keeps monitoring and stores data during an internet outage. Live phone alerts and remote control resume when the connection returns. That distinction matters when you are away: the device can be running while your phone cannot reach it.
What happens in a power outage?
Plan power backup along with the valve. Moen’s optional Flo battery provides up to four hours of device power and is intended for indoor use. Remote access also needs the home’s internet equipment running.
Keep the manual house shutoff accessible. Resideo’s L5 also has an emergency mechanical handle; operating that handle does not update the valve position shown in the app. We demonstrate the actual model’s manual control during setup.
Will watering the yard or cleaning the softener set it off?
Those uses belong in the setup. A softener’s regeneration is its automatic cleaning cycle, often scheduled overnight. Pool filling and irrigation can also look unusual to a flow monitor.
Flo offers scheduled overrides for expected heavy use. Its Sleep mode disables alerts and automatic shutoff for the chosen period. Use the setting that fits the activity and restore normal protection afterward.
Moen: planned water-use settings ↗ · Moen: Home, Away and Sleep modes ↗
The app reports a leak. What should I look for?
Look for wet floors, dripping connections and water that keeps running after use. A toilet refilling between flushes can explain an alert without leaving a puddle. Check which sensor reported water before restoring a closed supply.
When the cause stays hidden, leak diagnosis follows the water through the affected plumbing. Save the alert’s time and water-use history; they help narrow the search.
The handover should include a real demonstration.
We test closure, verify the alerts reach your phone, show you how to reopen and manually isolate the supply, and set the model’s maintenance cycle. Place sensors again after cleaning or moving an appliance, and check their operation on the maker’s schedule.
Ask about a smart shutoff ↗A few useful answers
Common questions.
Will an automatic shutoff work during a power or internet outage?
Power keeps the motor and electronics working; internet access supports remote alerts and app control. Offline behavior and battery backup vary by product. We explain those details for the chosen device and show everyone in the home how to use the manual shutoff.
Does Moen Flo keep working without Wi-Fi?
With power available, Flo continues monitoring and stores data during an internet outage. Live phone alerts and remote control need the internet connection.
How do I plan power backup for a smart shutoff?
Plan around the exact valve and power supply. Moen’s optional Flo battery provides up to four hours of device power and is intended for indoor use. Keep the manual house shutoff accessible.
Can a softener trigger a smart-shutoff alert?
Its regeneration cycle uses water automatically, often overnight. Include that cycle and other planned heavy uses when setting up the monitor. Flo provides scheduled overrides for expected use.
Sources & public guide record
Maintained by Mountain Man Plumbing · Utah Master Plumber, Lic. #12992295-5501.
- Moen: Flo water monitoring and automatic shutoff ↗
- Moen: Flo installation guide ↗
- Resideo: L5 Wi-Fi water shutoff instructions ↗
- Moen: Flo operation without Wi-Fi ↗
- Moen: Flo battery backup ↗
- Moen: planned water-use overrides ↗
- Moen: system modes ↗
Guide version 2026.09.10.1 · References checked 2026-09-10.