The Home Building Industry's Technical Information Resource

Back to Standard View
Search TechnologiesAbout Technology Inventory
Browse by Building System

Symbol Legend
Adobe Acrobat Reader required for PDF documents

PDF documents require the free Adobe Reader.

All PDF documents open in a new browser window. Close the browser window to return to the site.

Water Flow Leak Detectors and Shutoff Valves

Prevent extensive water damage from plumbing failures

An electric shutoff valve installed on the main water line can shut off water when sensors detect flooding.

Damage to homes caused by burst piping can be expensive to repair. By the time the leak is discovered, hundreds of gallons of water may have already flooded the home. Automatic shutoff valves can prevent extensive water damage from plumbing failures. The valves contain sensors that cut off water flow in the event of a leak, thereby preventing flooding.

There are two types of automatic shutoff valves. Whole house systems are designed to turn off the water near the service valve to prevent water flow throughout the home once a leak is detected. Other systems are designed to shut off flow to one appliance such as a washing machine, dishwasher, or ice machine.

Each type of valve uses a sensing device to determine the presence of a leak. These sensing devices can be an integral component of the plumbing system and are wired directly or wirelessly to communicate with the shutoff valve. One type of sensor is placed in an area where a leak may occur; for instance, on the floor beside a washing machine. Other sensing devices may measure the rate or duration of water flow, or detect the operation of the appliance to activate the valve.

Safety and Disaster Mitigation

Water leak detectors and automatic shutoff valves are designed to prevent extensive water damage from plumbing failures.


Valves and leak detectors may be purchased from a local plumbing supply distributor, or in some cases, directly from the manufacturer.

For accurate detection, systems that use remote moisture sensing units rely on placing the unit in a location most likely to flood if a water line breaks. Units that use flow rate to detect a pipe burst must use a bypass function to prevent automatic shutoff if an activity, such as lawn watering, uses a large amount of water.

Systems start at about $75 plus installation. Some products can be installed by anyone with basic plumbing skills and common tools.

Operational cost will be minimal - systems use a small amount of electricity.

Not Applicable

Not Applicable

Basic plumbing and electrical skills are required to install water leak detectors and automatic shutoff valves. Most products have been designed to adapt to existing plumbing systems.

Varies, depending upon manufacturer.

Water leak detectors and automatic shut-off valves will help to prevent water damage from a leaking hot water tank, clothes washer water pipe connection, or a burst water supply pipe or connection.

Disclaimer: The information on the system, product or material presented herein is provided for informational purposes only. The technical descriptions, details, requirements, and limitations expressed do not constitute an endorsement, approval, or acceptance of the subject matter by the NAHB Research Center. There are no warranties, either expressed or implied, regarding the accuracy or completeness of this information. Full reproduction, without modification, is permissible.