Water Leak Detection Systems
Condensed from an
article by State Farm Insurance
Water damage can occur
almost anywhere in your house. Water-using appliances and fixtures, such as
refrigerators with icemakers, dishwashers, washing machines, toilets and water
heaters are common locations of leaks.
Unfortunately, slow leaks at these appliances and fixtures are often times impossible
to see until it is too late. If it goes undetected, a slow leak can lead to
rotting house framing and sub-floors, and can be a precursor to a catastrophic
leak that can release several gallons of water per minute, causing extensive
water damage. A water leak detection system may help prevent these problems.
Types of Water Leak Detection Systems
Leak detection systems
can be either active or passive.
Passive leak detection systems are intended to alert you of
a leak. They generally sound an audible alarm tone and some may also feature
a flashing light.
Passive systems are frequently battery-operated, stand-alone units. They are
inexpensive and easy to install. Some simply sit on the floor while others may
be wall mounted. A moisture sensor is located on the floor and activates the
alarm when it becomes wet.
need to be checked regularly and the batteries should be changed at least every
year. Most devices will "chirp" when the battery is low, similar to
Passive systems only help reduce water damage if someone hears the warning
tone and acts to stop the leak. They are especially useful in locations
where it is easy for someone to hear the alarm such as near refrigerators, dishwashers,
Active leak detection systems usually generate some type of
alarm, but also perform a function that will stop the water flow. They feature
a shut-off valve and some means to determine that a leak is occurring. Most
devices use moisture sensors to detect a leak. Other systems use a flow sensor
and a timer to determine that something is leaking and the water needs to be
An active leak detection system can either operate at an individual appliance
or it can operate and control a whole house.
Individual Appliance systems are designed to detect a leak
from an appliance, such as a washing machine or water heater. When a leak is
detected, an alarm is activated and the water supply to the appliance is automatically
Depending on the type of device, the homeowner may be able to install these
systems without any special tools. However, in some cases a qualified plumber
may be needed.
systems shut off the main water service when a leak is detected. An
automatic shut-off valve is installed on the main water service piping between
the water meter and first branch piping. This valve usually requires 115 volt
electrical service. Some models feature a battery back-up.
Some whole house systems monitor several moisture sensors (also called water
sensors). These detectors are installed on the floor below water-using appliances
These detectors may be hard-wired, meaning a wire must be routed through the
home between the sensors and the control valve, or wireless. Wireless systems
utilize battery-operated sensors that send a radio signal to the control valve
if a leak is detected. The wireless systems are usually easier to install, especially
in existing homes. However, because each sensor has a small radio transmitter,
these systems often cost more. The batteries in wireless systems also must be
regularly maintained and replaced.
Some whole house systems
use a flow sensor and timer that are programmed to accommodate the water usage
patterns of the home. When water usage exceeds the programming, the device sends
an alarm and shuts off the water service. Most of these devices feature "at-home"
and "away" settings for when the home is or is not occupied.
Convenient Features of Some Leak Detection Systems
Some models of
leak detection systems can be connected into a home's security or fire alarm
panel. If it detects water, it can send an alarm to an off site monitoring
Most whole house
systems feature a panic switch. In an emergency, pressing a button will
automatically close the detection system's water service valve. Pressing
another button will reset the system.
Some of the whole
house systems that use remote water sensors also have temperature sensors.
If the temperature at the sensor(s) in the home drops below a specified
point, the detection system will send an alarm and close the automatic shut-off
valve to lessen or prevent water damage from frozen pipes.
Some control panels
can identify which moisture sensor detected the leak while some can only identify
that there is a leak. Knowing which moisture sensor detected a water leak will
make it easier to find and repair the problem.
Each house has different
circumstances. Every homeowner should assess their own situation to decide what
type of system and features best fit their needs. The next step is to contact
the water leak detection device manufacturer to obtain product literature and
to ask questions about their systems. State Farm believes the information contained
in this article is reliable and accurate. We cannot, however, guarantee the
performance of all items demonstrated or described in all situations. Always
consult an experienced contractor or other expert to determine the best application
of these ideas or products in your home.