Hello Orville,

The unit is attached to the main water line where it enters the home. It must be connected to the cold water feed before it splits to your water heater. This is typically in either a garage, crawlspace or basement (depending on type of home). It must be installed vertically and at least 6 inches above the ground. The port sizes on this unit are 1-1/2" and can use either a standard 1-1/2" male threaded adapter or a 1-1/2" thread male compression fitting (if connecting to copper).