A refrigerator water filter sits behind the appliance on a small supply tube that feeds the ice maker and the dispenser. The job is simple when you do the steps in order. Most leaks come from skipping a step or cutting the tube at a bad angle.

Before you start

Check that the filter kit's fittings and tube size match the line you have. Look at the existing supply tube, which may be flexible, plastic, or copper, because each one needs a different fitting approach. Confirm you can reach the shutoff valve behind the fridge and that you can pull the unit out far enough to work without kinking the line. Have a towel and a bucket ready.

Step 1: Shut off and relieve pressure

Close the supply valve that feeds the fridge. Then run the dispenser briefly so the water and pressure left in the line drain out. Expect a small amount of water when you disconnect the old tube.

Step 2: Cut the tube square

Use a tube cutter or a sharp blade to make a clean, square cut. A ragged or angled cut is the most common reason a push or compression fitting fails. Remove any burrs from the inside and outside edge. Mark the tube at the insertion depth the fitting requires so you know when it is seated.

Step 3: Mount the head and connect the fittings

Attach the filter head to its bracket in a spot where you can still reach the cartridge later. Seat the tube fully into the fitting. Tighten a nut only as far as the instructions say, and do not overtighten plastic parts, because they can crack without any visible warning.

Step 4: Open the valve slowly and purge

Open the supply valve slowly while you watch every joint. Run the dispenser for the time the instructions give, which clears trapped air and loose carbon fines. Keep the bucket under the line during this stage.

Step 5: Dry check, then recheck

Dry each joint with a paper towel and look again after an hour, then again the next day. A slow weep often shows up as a faint ring or a bead of moisture before it becomes a drip. Look at the back of the fridge and the floor beneath it for dampness or staining.

When to stop and ask

If the fitting type is not in the kit, or the existing tube is brittle, cracked, or stiff with age, stop. Ask the installer or the manufacturer which adapter fits your line rather than forcing a connection. Keep the old fittings until the new connection passes the next-day check.