Introduction
The FloodStop FS3/4NPT V4 is an automatic water shut-off system designed to prevent water damage from water heater leaks. It consists of a motorized valve, a control unit, and a water sensor. Upon detecting water, the system automatically closes the valve to stop the water flow and sounds an alarm, providing protection for your home.
Safety Information
- Read all instructions carefully before installation and operation.
- Ensure the main water supply is turned off before installing the valve.
- Disconnect power to the water heater before installation.
- Installation should be performed by a qualified plumber or technician if you are not comfortable with plumbing work.
- Do not expose the control unit or sensor to direct water spray or extreme temperatures.
- This product is designed for water damage prevention; it is not a substitute for regular maintenance of your water heater.
Package Contents
The FloodStop FS3/4NPT V4 kit includes the following components:
- One 3/4" Motorized Valve
- One FLOODSTOP Control Unit
- One Water Sensor
- One Wall Adapter (Power Supply)
- Mounting Hardware
Setup and Installation
Follow these steps for proper installation of your FloodStop system:
- Connect the FLOODSTOP Valve: Install the 3/4" motorized valve upstream on the cold water inlet pipe of your water heater. Ensure the valve is installed in the correct flow direction as indicated on the valve body.
- Mount the Control Panel: Securely mount the FloodStop Control Unit to a nearby wall using the provided mounting hardware. Choose a location that is easily accessible and visible.
- Place the Water Sensor: Position the water sensor on the floor directly under your water heater, or in the water heater pan if one is present. The sensor should be placed where water would first accumulate in the event of a leak.
- Connect Components and Power: Plug the valve assembly cable into the control unit. Connect the water sensor cable to the control unit. Finally, plug the wall adapter (power supply) into a standard electrical outlet and connect it to the control unit. The control unit can also operate on 4-AA batteries for backup power.

Image: FloodStop system components. This image shows the motorized valve, control unit, and water sensor, which are the main parts of the system.

Image: Easy installation diagram. This diagram illustrates the three main steps for installing the FloodStop system: connecting the valve, mounting the control panel, and placing the water sensor.
Operating Instructions
- Normal Operation: Once installed and powered, the system is in standby mode. The valve remains open, allowing water flow to the water heater.
- Leak Detection and Shut-off: If the water sensor detects water, the control unit will immediately close the motorized valve, stopping the water supply to the water heater. An audible alarm will sound to alert you of the leak.
- Alarm Reset: To silence the alarm, remove the water from the sensor. The valve will remain closed until manually reset.
- Manual Valve Control: The control unit typically has buttons (e.g., OPEN, CLOSE) to manually operate the valve. Refer to the control unit for specific button functions.
- Battery Backup: The system can operate on 4-AA batteries, providing continued protection during power outages. Ensure fresh batteries are installed.
- Alarm Relay Output: The control unit features a normally open relay output that can be connected to an external alarm system, automatic phone dialer, or other compatible devices for remote notification.
- Monthly Self-Test: The system may perform a monthly self-test of the valve to ensure proper functionality. No user action is typically required during this test.
Maintenance
- Battery Replacement: Replace the 4-AA backup batteries every few years or when the control unit indicates low battery.
- Sensor Cleaning: Periodically inspect the water sensor for dust or debris and clean it as needed to ensure accurate detection.
- System Test: It is recommended to periodically test the system by placing a small amount of water on the sensor to confirm the valve closes and the alarm sounds. Dry the sensor thoroughly after testing.
Troubleshooting
- Valve Does Not Close:
- Check if the control unit has power (AC adapter or fresh batteries).
- Ensure the valve cable is securely connected to the control unit.
- Verify the water sensor is clean and properly connected.
- Alarm Sounds Continuously:
- Check the water sensor for any moisture and dry it completely.
- Inspect the area around the water heater for actual leaks.
- No Power to Control Unit:
- Ensure the AC adapter is plugged into a working outlet and securely connected to the control unit.
- Check and replace the 4-AA backup batteries if necessary.
Specifications
| Model Number | FS3/4NPT v4 |
| Brand | FloodStop |
| Valve Size | 3/4" NPT |
| Power Source | AC Adapter (230 Volts AC) and 4-AA Batteries (backup) |
| Sensor Technology | Water Sensor |
| Item Weight | 1.92 pounds |
| Product Dimensions | 12 x 8 x 3 inches |
| UPC | 696727497096 |
Warranty Information
Specific warranty details are not provided in this manual. Please refer to the product packaging or contact FloodStop customer support for comprehensive warranty information.
Support
For further assistance, technical support, or to inquire about replacement parts, please contact FloodStop customer service. Contact information can typically be found on the product packaging or the manufacturer's official website.





