How to Hook Up a Water-Powered Back-Up Sump Pump System

Mount the back-up sump pump. You want to position the sump pump in the pit so that the float sits above the existing sump pump, but deep enough so that the intake valve can pull water. This is because you only want the back-up sump pump to activate when the existing sump pump is not functioning. Once you've determined the proper height, mount two wood planks parallel to the floor against the basement wall where your sump pump pit is to provide an anchor for your kleets and mounting hardware. Then, drill the mounting hardware and kleets into the planks to hold the back-up sump pump in place at the correct height.

Connect the back-up sump pump to the nearest water connection. You will need to use three-quarter-inch copper pipe and solder the connections between the back-up sump pump and the water pipe so that city water can flow through. The copper pipe should connect from the water pipe down to the back-up sump pump's connector on the top of the unit. Soldering the connections in place ensure a seamless, leak-free connection.

Disconnect the electrical from the primary sump pump. This is to avoid getting wet. You will need to then cut the pump valve leading outside to create an output connection from the back-up pump to the existing pump's output pipe. Using PVC pipe, connect the back-up sump pump at the output point, then run the pipe to the original pump's output connection pipe. You can connect the pipe in a "Y" formation by cutting and gluing the pipe in place.

Ensure the backflow preventer portion of the back-up sump pump cannot be clogged. Unscrew the backflow preventer and quickly turn on the valve to "flush" the pipe of any possible remnants of solder or glue. Turn off the valve and screw the backflow preventer securely back into place. You are now ready to test.

Plug in your original sump pump, then unplug it to simulate an interruption in power. The pit would then continue to fill with water as if it were raining, activating the float to rise and open the back-up sump pump valve. The pump should then begin using the pressure of the city water to create a vacuum that sucks water out of the pit and out of your house.