How to Connect Your Refrigerator's Ice Maker Water Line

Connect the water supply line before you plug in the refrigerator

The ice maker needs a cold water line running from your home's water supply to the back of the refrigerator. This connection happens before you move the unit into its final spot or turn it on. Most refrigerators come with a plastic water line coiled inside the box, but you will need to run it from the water source to the back of the fridge—and that means deciding whether to tap into your cold water line under the sink or use a saddle valve on the main supply.

The job takes about an hour if you have the right tools and your water shutoff valve is accessible. If you rent, check your lease first—some landlords require a plumber to do this work, and some buildings have rules about which water lines you can tap into.

Do not turn on the ice maker until you have run water through the line and flushed out the air and any manufacturing debris. Air in the line will cause the ice maker to cycle without producing ice, and debris can clog the inlet valve.

Key Takeaways

• Shut off your home's water supply at the main valve or the shutoff under the sink before you begin any connection work.
• A saddle valve (also called a piercing valve) lets you tap into an existing copper or plastic cold water line without cutting it, and costs $8 to $15.
• The water line must slope slightly downward from the source to the refrigerator to prevent air pockets and water pooling.
• After connecting the line, run water through it for 5 to 10 minutes to clear air and debris before you turn on the ice maker.
• If your refrigerator has a water filter, install it before you run water through the system, or the unfiltered water will go straight into the ice maker.

Locate your water source and shut off the supply

The easiest water source is the cold water line under your kitchen sink. Look under the sink and find the copper or plastic line that feeds the faucet. This line usually has a shutoff valve on it already—turn it clockwise until it stops. If there is no shutoff valve on the cold line itself, turn off the main water shutoff for your entire house, which is typically in the basement, crawlspace, or outside near the foundation.

If you cannot access the line under the sink (because of cabinet layout or because your landlord forbids it), you can tap into the main cold water line that enters your house. This line is usually in the basement or crawlspace and is thicker than the line under the sink. A saddle valve works on either location, but tapping the main line means the ice maker will have water pressure even if you turn off the kitchen sink shutoff.

After you shut off the water, turn on the kitchen faucet and let it run until no water comes out. This relieves pressure in the line so you do not get sprayed when you make the connection.

Install a saddle valve or use an existing shutoff

A saddle valve (also called a piercing valve) clamps onto an existing water line and punctures it without requiring you to cut the line or drain the system. It costs $8 to $15 and comes with a clamp, a valve body, and a small needle that does the piercing. You can buy one at any hardware store or home center.

To install a saddle valve, clamp it around the cold water line at a spot that is easy to reach and at least 12 inches away from any existing shutoff valve or connection. Tighten the clamp bolts evenly—do not over-tighten, or you will crack the line. Then slowly turn the valve handle clockwise until you feel resistance; this pushes the needle through the line. Stop when you feel it pierce through. Do not force it or turn it more than a quarter turn past the resistance point.

If your water line already has a shutoff valve with an outlet port (a small threaded connection), you can screw a compression fitting directly onto that port instead of using a saddle valve. This is cleaner and more reliable if the option exists. Ask at the hardware store for a compression fitting that matches your line diameter—usually 1/4 inch.

Run the water line to the refrigerator with proper slope

Uncoil the plastic water line that came with your refrigerator and run it from the saddle valve (or shutoff port) to the back of the fridge. The line must slope slightly downward toward the refrigerator—about 1/4 inch of drop per foot of horizontal run. This prevents air pockets from forming and stops water from pooling in low spots.

Secure the line to the wall or floor with plastic clips every 12 to 18 inches so it does not kink or get pinched by cabinet doors. Avoid running the line through hot areas like behind the stove or near heating ducts, because heat can degrade the plastic and reduce water pressure. If you must run it through a warm space, wrap the line with foam pipe insulation.

At the back of the refrigerator, connect the line to the inlet valve using the compression fitting that came with the fridge. Hand-tighten the fitting first, then use an adjustable wrench to tighten it one more half-turn. Do not over-tighten—compression fittings seal with a ferrule (a small metal ring), and crushing it will cause leaks.

Flush the line and install the water filter

Turn the water back on at the shutoff valve or main supply. Let water run through the line into a bucket for 5 to 10 minutes. This clears air from the line and flushes out any debris or manufacturing residue that could clog the inlet valve or damage the ice maker.

If your refrigerator has a water filter cartridge (most modern models do), install it now, before you turn on the ice maker. The filter screws or clicks into a housing on the back or inside the fridge. Check your manual for the exact location and installation steps. A new filter ensures that sediment, chlorine, and other particles do not end up in your ice or drinking water.

After the filter is installed, run another 2 to 3 minutes of water through the line to flush the filter media. Some filters come with a bypass valve that lets water flow around the filter if it gets clogged, so flushing helps you confirm the filter is working and not blocked.

Turn on the ice maker and watch for leaks

Once the line is flushed and the filter is in place, you can plug in the refrigerator and turn on the ice maker. Most models have an on/off switch or lever on the ice maker itself, usually located inside the freezer compartment. Flip it to the on position.

The ice maker will cycle and try to fill with water. Listen for the sound of water flowing into the ice tray—you should hear a brief hum and then a rushing sound as the inlet valve opens. The first batch of ice may be cloudy or taste slightly off because the line still contains some air and residue. Throw away the first two or three batches and run the dispenser (if you have one) a few times to clear the system.

Check the connection at the back of the refrigerator and under the sink for drips or leaks every 30 minutes for the first few hours. A small drip at a compression fitting can usually be tightened another quarter-turn with a wrench. If water is pooling or spraying, turn off the water immediately and check that the fitting is seated properly.

Troubleshoot common connection problems

If water does not flow into the ice maker after 10 minutes, the line may have an air pocket or the inlet valve may be stuck. Turn off the water, disconnect the line at the refrigerator, and run water into a bucket for another minute to clear any remaining air. Reconnect the line and try again. If water still does not flow, the inlet valve may need replacement—this is a $50 to $150 part that requires removing the back panel of the fridge.

If the ice maker cycles but produces no ice, the water pressure may be too low. Most ice makers need at least 20 pounds per square inch (psi) of water pressure to function. If you tapped into a line that also serves other fixtures, running the dishwasher or filling a bathtub will reduce pressure to the ice maker. You can test pressure with an inexpensive gauge ($10 to $20) that screws onto a faucet. If pressure is consistently below 20 psi, you may need a booster pump or a different water source.

Leaks at the compression fitting usually mean the ferrule is not seated correctly or the fitting is not tight enough. Turn off the water, disconnect the fitting, and inspect the ferrule for cracks or deformation. If it looks damaged, replace it with a new ferrule from the hardware store. If it looks fine, reconnect and tighten the fitting another half-turn.

Frequently Asked Questions

Can I use hot water for the ice maker?

No. Ice makers require cold water, and hot water will damage the inlet valve and produce ice that melts quickly. Always tap into the cold water line, never the hot line. If your only option is a line that carries both hot and cold water, consult a plumber before proceeding.

What if I do not have a shutoff valve under the sink?

You will need to turn off the main water supply for your entire house before you install the saddle valve. After the saddle valve is in place and the line is connected, you can turn the main supply back on. In the future, consider having a plumber install a shutoff valve under the sink so you do not have to shut off water to the whole house for maintenance.

Do I need a plumber to connect the ice maker line?

If you are comfortable with basic hand tools and can access your water line, you can do this yourself. If your lease requires a plumber, or if you are unsure about shutting off water or tightening fittings, hire a plumber. The cost is usually $100 to $200 and takes about an hour. It is worth the expense if it means avoiding water damage.

How often should I replace the water filter?

Most manufacturers recommend replacing the filter every 6 months or after 300 gallons of water, whichever comes first. If you have hard water or sediment in your supply, you may need to replace it more often. Check your manual for the exact schedule and filter part number.

What if water leaks from the connection after I turn the water back on?

Turn off the water immediately and let the line dry. Check that the compression fitting is hand-tight, then use a wrench to tighten it one more half-turn. Turn the water back on slowly and watch for leaks. If water still drips, turn off the water again, disconnect the fitting, and inspect the ferrule for cracks. Replace it if damaged, or reconnect and tighten further if it looks intact.