How to Cap a Refrigerator Water Line When You're Not Using It
Why and when to cap your refrigerator water line
Capping your refrigerator water line stops leaks, prevents mold growth inside the line, and protects your floor if you're moving the fridge, doing repairs, or simply not using the ice maker and water dispenser. A capped line also keeps dust and debris out of the tubing, which matters because that line runs directly to the parts that dispense water you drink.
You need to cap the line if you're disconnecting your refrigerator from the water supply for any reason — whether temporarily (during a move or cleaning) or permanently (if you've decided not to use the ice and water features). Even if the fridge is still plugged in and running, an uncapped line can leak slowly onto your floor or into the cabinet beneath it, and that moisture creates the conditions for mold.
The job takes about five minutes and requires only a cap that fits your tubing diameter. You do not need to shut off the main water supply to your house, though you will need to release the pressure in the line first.
Key Takeaways
- Turn off the water supply valve behind or under your refrigerator, or locate the main shutoff if there is no dedicated valve.
- Open the water dispenser on the fridge door to release pressure and drain remaining water from the line.
- Disconnect the water line at the point where it enters the refrigerator or at the shutoff valve, depending on your setup.
- Slide a cap onto the exposed end of the tubing and tighten it by hand or with a wrench, depending on the cap type.
- Store the disconnected line in a safe place if you plan to reconnect it later, or leave it capped if the feature will stay unused.
Locate and turn off the water supply valve
Most refrigerators have a dedicated shutoff valve installed where the water line enters the cabinet or wall behind the fridge. This valve looks like a small knob or lever, usually made of plastic or metal, and it sits on the water line itself. Check behind the refrigerator first, along the wall or inside the cabinet space. If your fridge is built-in or installed against a wall, the valve may be under the sink or in a nearby cabinet.
If you cannot find a dedicated valve, you will need to use the main water shutoff for your house. This is typically located in the basement, crawlspace, or utility room, and it controls water to the entire home. Turning it off is safe and will not damage anything, but it does stop water to every faucet and appliance in the house, so you may want to work quickly or choose a time when no one else needs water.
Turn the valve clockwise (to the right) until it stops. You should feel resistance, but do not force it — a gentle, steady turn is enough. If the valve is stiff or will not turn, apply a small amount of penetrating oil and wait a few minutes before trying again.
Release pressure and drain the line
After the water is shut off, open the water dispenser on your refrigerator door and let it run for 10 to 15 seconds. This drains the water that remains in the line and releases the pressure inside the tubing. Without this step, water will spray or drip when you disconnect the line, and you may not be able to fit a cap on a pressurized line.
If your refrigerator has an ice maker but no water dispenser on the door, you can still release pressure by opening the ice maker compartment and waiting a moment. Some models have a small test button or lever inside the ice maker that you can press to trigger a cycle and release pressure. Check your refrigerator manual if you are unsure.
After you release the pressure, place a towel or small bucket under the point where you plan to disconnect the line. Even after draining, a small amount of water may still be inside the tubing, and the towel will catch it.
Disconnect the water line safely
The water line connects to your refrigerator at one of two points: either at the inlet valve on the back of the fridge itself, or at a shutoff valve installed in the wall or cabinet. Locate the connection point and look for the fitting that holds the tubing in place.
Most refrigerator water lines use a compression fitting or a push-to-connect fitting. A compression fitting has a small nut that you turn counterclockwise (to the left) by hand or with an adjustable wrench. A push-to-connect fitting (also called a quick-disconnect) has a small collar or clip that you press or pull to release the tubing. Check which type you have before you start — the manual or a photo of the back of your fridge can help.
For a compression fitting, hold the fitting body steady with one hand and turn the nut counterclockwise with the other. Turn slowly and stop as soon as water stops dripping. For a push-to-connect fitting, press the collar inward or pull the clip outward (depending on the design) and gently pull the tubing straight out. Do not bend or kink the line as you disconnect it.
Choose and install the correct cap
Water line caps come in two main types: compression caps and push-to-connect caps. The cap you need depends on the type of fitting you just disconnected. If you disconnected a compression fitting, you need a compression cap. If you disconnected a push-to-connect fitting, you need a push-to-connect cap.
Caps are sized by the outer diameter of the tubing, which is usually 1/4 inch for refrigerator water lines. Measure the tubing diameter with a ruler or calipers if you are unsure, or bring a small piece of the tubing to a hardware store and ask for a cap that fits. Caps cost between two and five dollars and are sold in the plumbing section of most hardware stores.
To install a compression cap, slide it onto the exposed end of the tubing and hand-tighten the nut. Once it is snug, use an adjustable wrench to turn it another quarter turn clockwise. Do not over-tighten — you only need enough pressure to create a seal. To install a push-to-connect cap, simply push it onto the end of the tubing until you hear or feel a click. The cap will lock in place automatically.
Store or secure the capped line
If you plan to reconnect the water line later, coil it loosely and store it in a dry place away from heat and direct sunlight. Do not fold or crease the tubing sharply, as this can damage the interior and cause leaks when you reconnect it. A basement shelf, garage cabinet, or utility closet works well.
If the line will stay capped permanently because you do not use the ice maker or water dispenser, you can leave it in place behind the refrigerator or tuck it into the cabinet space. Make sure the cap remains tight and the line does not get pinched or damaged by the refrigerator or other objects.
Check the cap every few months to make sure it is still tight and no water is leaking. If you notice moisture around the cap or on the floor, turn off the water supply again and re-tighten the cap or replace it if it is cracked or damaged.
Frequently Asked Questions
Do I have to turn off the main water supply to cap the line?
No. A dedicated shutoff valve behind the refrigerator is enough. If your fridge does not have one, you can use the main shutoff, but it is not required — you just need to release the pressure in the line by opening the water dispenser first.
What happens if I cap the line without releasing pressure?
Water may spray out when you disconnect the fitting, and you may have trouble getting the cap on tight. Releasing pressure takes only 10 to 15 seconds and prevents mess and frustration.
Can I use any cap, or does it have to match the fitting type?
The cap must match the fitting type you disconnected. A compression cap will not seal a push-to-connect fitting, and vice versa. Bring the tubing or a photo of the fitting to a hardware store if you are unsure which type you need.
Is it safe to leave the line capped if the fridge is still running?
Yes. The ice maker and water dispenser will simply not work, but the refrigerator itself will run normally. The capped line prevents leaks and keeps the tubing clean.
What should I do if the cap leaks after I install it?
Turn off the water supply, remove the cap, and check the end of the tubing for cracks or debris. Wipe the tubing clean with a dry cloth and install a new cap. If the tubing is cracked, you may need to cut off the damaged end with a tubing cutter and install a new cap on the fresh end.