This project utilizes a Furman power controller to power off an appliance when water is detected by the Floodstop system. This can be very useful to power off a washing machine, water recirculator, or tankless hot water heater if a leak is detected. In particular, appliances that can pump water such as a washing machine have an extra vulnerability for flooding and could potentially continue pumping water even if the water supply has been shut off by the Floodstop valve. For these types of devices, you may want to automatically power them off to ensure any motors or pumps are not contributing to the flooding condition.

Project Objective

The following diagram illustrates this project's goals.

Shopping List

• Floodstop Protection System (See a complete listing of available Floodstop products)
• Furman Power Controller (See a listing of other Furman Power Controllers)
• A length of 2-conductor low-voltage wire (bell wire, alarm wire, speaker wire, etc.) (* length is based on your installation requirements)

View all Floodstop models View other supported Furman Power Controllers

Furman MP-15 / MP-20

The Furman power controller product line is a heavy-duty industrial power controller that can easily be controlled externally with either a dry contact closure or a low-voltage DC signal depending the the model. This makes the Furman power controller prefectly suited to work with the Floodstop contoller to add the capability of powering off an appliance when a leak is detected.

The Furman MP-15M (15-amp) / MP-20 (20-amp) is the older version of the Furman power controller. This model is no longer in production but can often be found on eBay or used on Amazon. The MP-15 is adequate for most installations as most modern appliances draw (require) less than 15 amps and most homes are only wired for a 15-amp circuits. The MP-20 is designed for 20-amp circuits and typically requires a special 20-amp outlet. If you have a MP-20 but only have 15-amp outlets, you can cut off and replace the plug on the MP-20 with a standard 15-amp plug but you must take care to never overload the circuit with an appliance that draws more than 15-amps.

The Furman MP-15/20 is powered on by default and can be powered off simply by closing the circuit between the 12VDC and REM (remote) terminal pins on the Furman.

Floodstop + Furman MP-15 / MP-20

The Furman MP-15/20 is extremely simple to integrate with the Floodstop's N.O. (normally-open) dry contacts. The Furman MP-15/20 is powered on while the Floodstop's output circuit is OPEN and will be powered off when the Floodstop's output is closed providing a closed circuit between the 12VDC and REM (remote) terminal pins on the Furman. The logic diagram below depicts how we will use the low-voltage signal across the Floodstop's dry contact output connection to control the Furman MP-15/20 power controller.

Connect Floodstop to the Furman MP-15 / MP-20

To control the Furman MP-15/20 with the Floodstop you need only to connect one of the Floodstop's N.O. output conductors to the 12VDC pin on the Furman and the second Floodstop N.O. output conductor to the REM (remote) pin on the Furman.

First located the N.O. (normally-open) output on the bottom of the Floodstop controller. This is the port we will be using to interface to the Floodstop.

A short connection wire should have been included in the Floodstop package that includes the necessary plug to connect to the Floodstop's output port. Most likely this connection "pigtail" will be too short for your final installation, so you can extend this connection wire by splicing on the end of a 2-conductor low-voltage wire that meets your project's length requirements.

You will need to attach one of the conductors from the Floodstop to the +12 VDC terminal on the Furman MP-15/MP-20 and the other conductor to the REM (remote) terminal. In this project, it does not matter which conductor on the Floodstop is connected to which of the 12VDC or REM terminals. Polarity does not matter in this circuit.

That is all there is to this project! The Furman should now power off the high-voltage circuit the appliance is plugged into anytime the Floodstop senses a water leak! Please note, once the sensor is tripped, it does not automatically restore power when the Floodstop stops sensing moisture. To restore power to the appliance, the Floodstop sensor must be completely dry and you must press the OPEN button on the Floodstop controller. This action will both open the water valves and signal the Furman to restore power.

Internal Jumper on the Furman MP-15 / MP-20 (Momentary -vs- Maintained)

The Furman MP-15 / MP-20 supports two modes of operation: Maintained and Momentary. This project requires that the Furman be configured in Maintained mode. The Furman should have been shipped from the factory set to Maintained mode but if you acquired the unit second hand the mode may have been changed. Simply remove the rear cover plate by removing the four screws on the rear of the unit and look for the Maintained and Momentary jumper pins. You will want to make sure that the jump is on the Maintained pins and not the Momentary pins.

My Installations

Washing Machine

The photo below illustrates my washing machine installation. I am using this project to protect my washing machine from an accidental flood. I am using the Furman MP-20 model as well as the older Floodstop controller. Shutting off the water supply alone via the Floodstop valve is not enough to protect against a washing machine flooding disaster. There are two significant risk factors, A leak could be detected when the washing machine is trying to empty it's contents, for example if the drain line were blocked. Without powering off the washing machine, it would continue to pump all its contents out and potentially cause a flood. So this project will ensure that both the supply water and power are cut off to the washing machine to prevent it from flooding.

Hot Water Heater

The next photo is of my tankless hot water heater installation. I am using this project to protect my basement from accidentally flooding if the water heater were to leak. I am using the Furman MP-20 model and the newer (V4) Floodstop controller. The tankless hot water heater contains an internal recirculation pump and the installation also has an external condensate pump. The Floodstop + Furman will shut off these devices if a leak is detected. I wanted to power down both the internal recirculation pump and the condensate pump if any water leak is detected because shutting off the water supply may not be enough to stop a flodding condition.