Water damage is one of the most common and expensive problems homeowners face. Many leaks start slowly in places that aren’t checked often, which means they can go unnoticed for a long time.

Small smart leak sensors are designed to detect water early and send an alert to your phone if moisture is detected.

These devices sit on the floor near appliances or plumbing connections and can help homeowners catch problems before they become much larger repairs.

If you’re new to smart sensor systems, you may want to start with our guide explaining how smart home sensors work.

Most Leak Sensors Connect to a Hub

Most smart leak sensors connect to a central device called a hub. The hub communicates with sensors placed around your home and sends alerts to your phone through the system’s mobile app.

Because of this, the hub is usually the first piece needed when setting up a smart sensor system.

You can see an example here:

See YoLink Hub on Amazon

Once the hub is installed, additional sensors and accessories can be added around the home to monitor areas where leaks are most likely to occur.

How Smart Leak Sensors Work

Leak sensors are small devices that sit directly on the floor near plumbing or appliances.

If water touches the sensor, the system sends an alert to your phone so you can investigate quickly.

These sensors don’t stop leaks from happening, but they can help notify you early enough to prevent major water damage.

Many homeowners place several sensors around the home in areas where plumbing failures are more likely to occur.

Common Places to Put Leak Sensors

Behind the Washing Machine

One of the most common sources of water damage in homes is a leaking washing machine hose.

Supply hoses can wear out or loosen over time, and because the area is usually hidden behind the machine, leaks may go unnoticed until water has already caused damage.

A leak sensor placed on the floor behind the washing machine can alert you if water begins collecting there.

You may also want to read about the washing machine hose many homes forget to replace, which is another common cause of leaks.

Under Kitchen Sinks

Small plumbing leaks often start slowly under sinks. A loose connection, worn washer, or slow drip can continue unnoticed for a long time inside a cabinet.

Placing a leak sensor under sinks can help detect moisture early before cabinets or flooring become damaged.

These areas are often among the first places homeowners choose to add sensors.

Under Bathroom Sinks

Bathroom sinks are another common location for slow plumbing leaks.

Placing a leak sensor inside the cabinet can help monitor for moisture that might otherwise go unnoticed.

Toilets (Supply Line and Tank Area)

Toilets connect to the home’s water supply through a small supply line behind the fixture. Over time these lines can wear out, loosen, or develop slow leaks at the connection point.

Most braided stainless steel toilet supply lines typically last about 5–7 years, while older rubber versions often fail sooner. Like many small plumbing parts, supply lines aren’t designed to last forever and are usually replaced periodically as part of normal home maintenance.

Placing a leak sensor on the floor behind or beside the toilet can help detect moisture early if a connection or supply line begins leaking.

You can also learn more about toilet supply lines and when they should be replaced.

Near Water Heaters

Water heaters can occasionally develop leaks as they age. Because they are often located in basements, garages, or utility rooms, problems may not be noticed right away.

A leak sensor placed near the base of the water heater can alert you if water begins collecting nearby.

Near Dishwashers

Dishwashers can sometimes develop slow leaks around connections or hoses.

A leak sensor placed near the appliance can help alert you early if water begins collecting on the floor.

Behind Refrigerators With Water Lines

Refrigerators with ice makers or water dispensers connect to a small water supply line behind the appliance. Over time these connections can loosen or the line itself can wear out.

Because the refrigerator sits against the wall, leaks may go unnoticed for quite a while.

A leak sensor placed on the floor behind or beside the refrigerator can help detect water early if the supply line begins leaking.

This can be especially helpful in kitchens where water damage could affect cabinets or flooring before anyone notices the problem.

In condos or multi-family homes, early alerts can be especially helpful since small leaks can sometimes affect neighboring units before they are discovered.

Interior Walls Near Outdoor Spigots

Outdoor hose spigots connect to plumbing inside the home, usually through an interior wall in a basement, crawlspace, or utility area.

If a pipe freezes, a connection loosens, or the valve begins to leak, water may appear inside the home near that wall.

A leak sensor placed on the floor near the interior side of the spigot connection can help detect water early before it spreads.

This is especially helpful in colder climates where freezing temperatures can stress outdoor plumbing.

Starting With One Sensor

Many homeowners begin by placing a single leak sensor behind a washing machine or under a sink.

Once they see how useful the alerts can be, they often add additional sensors in other areas of the home.

Because most smart sensor systems are modular, they can grow over time depending on what each homeowner wants to monitor.

You can see an example here of the Sensor:

See YoLink Water Leak Sensor on Amazon

Gigi Says

Many water problems in homes begin quietly.

A slow drip under a sink or a loose hose behind an appliance can go unnoticed for a long time.

Sometimes a small sensor and an early alert are all it takes to catch a problem before it becomes a much larger repair.