Step 1: Route the Tubing

Locate a cold-water line near the refrigerator. Below the sink is an obvious choice, and the icemaker tubing can be routed through the kitchen cabinet interiors. Or, you may need to cut a hole in the floor or wall behind the refrigerator reach a water pipe in a basement below.

Start by determining the tubing path from refrigerator to water source. If it’s through cabinets, use a drill with a 1/2” bit to bore holes through the interior cabinet sides near the back and out of the way of drawers and activity. If it’s through a floor or wall, first take measurements to determine where the tubing will emerge on the other side and whether any obstructions are in the way, and adjust as necessary before boring a hole.

Step 2: Connect the Water Supply Line

Connect copper or plastic water line tubing to the water inlet of the refrigerator, which is usually located on the rear of the refrigerator toward the bottom.

To attach the supply line, slide a compression nut over the tube with the threads toward the end of the tube. Next, slide a ferrule (included with the compression nut) over the tube, then insert the end of the tube into the refrigerator inlet. Finger-tighten the nut onto the inlet, and use two wrenches to tighten it: one to prevent the receptacle from turning, the other to tighten the nut.

Flexible plastic supply lines are easier to work with than copper tubing, but plastic is more easily damaged. If you use plastic, be sure to insert a brass reinforcement in each end of the supply line before you attach it to the refrigerator, water filter or supply valve. If you don't, you could crush the tubing when you tighten the compression fitting.

Step 3: Install the Water Filter

Cut the icemaker supply line in an area that will allow you to rest the water filter on the floor. Use a tubing cutter for copper supply lines, scissors for a plastic line.

Wrap Teflon tape around the threaded ends of the water filter.

Install compression nuts with ferrules onto each end of the supply lines that connect to each end of the water filter. Orient the filter as indicated according to the direction of flow (toward the refrigerator) and connect both supply line ends. Finger-tighten the compression nuts, then use two adjustable wrenches to tighten them.

Step 4: Tap Into an Existing Water Pipe

Use a saddle valve to tap into a home’s cold-water pipe. This allows you to add a new branch line to a water pipe without shutting off the main water supply. Attach the icemaker water line and assemble the valve on the pipe according to the manufacturer’s directions, then tighten the bolts evenly on both sides. Make sure the rubber seal is in place before you tighten the bolts. Turn the valve handle clockwise until its internal point pierces the cold-water line. Continue turning the valve until it is fully seated. Water will begin to flow to the refrigerator’s icemaker.

Step 5: Connect the Icemaker’s Power Supply

Follow the directions provided with the icemaker kit to make the unit’s electrical connections. If you have purchased the correct kit for your model, you'll be able to hook up your icemaker by making a simple electrical connection inside the refrigerator’s freezer compartment.