Refrigerator plumbing is needed when you buy a refrigerator that has an ice maker and water dispenser. You will have to install a refrigerator water line to satisfy both.
Not all refrigerators with ice makers need water lines
Many refrigerators with built in ice makers and water taps require connection to your kitchen’s water supply, though others have no plumbing at all. However, these plumbing-free refrigerators use a water tank to make their ice & water, which needs to be manually refilled.
Refrigerator water line size
Tubing Sizes. Most flexible copper refrigerator water lines have an outside diameter of 1/4 inch. Most flexible plastic water lines for refrigerators come with outside diameters of either 1/4 inch or 5/16 inch.
Installing the Refrigerator water line
Connect the refrigerator water line to the stop valve with a compression joint. Then attach the tubing to the back of the cabinets every 2 to 4 ft. using 1/4-in. nylon wire/cable clamps. Once you’re outside the last cabinet, don’t attach any clamps; just run the tubing to the floor near the water line hookup on the fridge.
Select the location for the valve on your water line. It is recommend using a vertical pipe, if available. If you must use a horizontal pipe, place the hole for the valve either on the top or side of the pipe. Avoid using the bottom of the pipe, as this may draw sediment into the ice maker.
To place the hole for the valve , drill a 1/4-inch hole into the cold water line for the valve. Take caution to not allow water to seep into your drill and make sure to only pierce one side of the pipe. Attach the valve to the pipe using two pipe clamps. Tighten the screws on the clamps until the sealing washer swells. Avoid over-tightening; you can crush the copper pipe if you apply too much pressure.