Water Leak Detection Systems

Provided by our friends at State Farm Insurance, with some minor edits and additions by THE NATURAL HANDYMAN 

If you think a leak detection system is in your future, there is a short list of manufacturers at the end of the article to get your shopping jump-started!

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.  The ZIRCON leak detector (shown below) will float and sound its alarm for up to 72 hours on a fully-charged battery.

Photo 1: Passive Water Leak Detection Devices

Battery-operated devices 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 smoke detectors.

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, or toilets.

Passive systems generally cost from $8.00 to $45.00.

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 turned off.

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 shut off.

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. Individual Appliance systems range in cost from $70 to $150 (device cost only).  

The system shown below is the Watts IntelliFlow. It has dual operation.  The clothes washer is plugged into it, letting it turn the water on or off automatically when needed!  Also, it features a floor-mounted leak detector should a hose burst while the machine is operating!

Photo 2: Individual Appliance Water Leak Sensing Device

Whole house 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, such as the FloodStopper System (photo 3) monitor several moisture sensors (also called water sensors). These detectors are installed on the floor below water-using appliances and fixtures.

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.

Figure 1: Whole House Water Leak Detection System which uses Remote Water Sensors
(Remote water sensors can either be wired to the control panel or the remote water sensors can be wireless and "communicate" with control panel by radio signals)

Photo 3: Whole House Water Leak Detection System using Remote Water Sensors

Thanks to our friends at State Farm Insurance from allowing us to reprint this combined article.