How to Stop an Outside Faucet Leak at the Shut Off Valve

A leaking outdoor faucet can lead to flooding, water damage, and higher utility bills. In many cases, the source of the leak is a faulty shut off valve inside the house that fails to completely stop water flow to the outdoor spigot. Replacing this worn out valve is often the best solution to stop water from dripping out of your exterior faucet.

With some basic plumbing repairs, you can solve this common home maintenance issue.

Identifying the Source of the Leak

When you notice water leaking from an outdoor faucet, the first step is confirming that the drips are coming from the shut off valve rather than the faucet itself. Here's how to determine the source:

• Locate the shut off valve inside your home that controls water supply to the leaky outdoor faucet. It's usually near an exterior wall or where the water line exits to the outside.
• Turn the shut off valve clockwise to the off position. This should completely stop water flow.
• Go outside and check if the faucet is still leaking. If it continues dripping, the shut off valve is not fully closing.
• Try turning the outdoor faucet handle off. If the drips stop, the issue may be with the faucet rather than the shut off valve.

Once you've isolated the leaking shut off valve as the culprit, you can move on to fixing the problem. Valves can fail due to age, loose parts, and mineral buildup.

Signs Your Shut Off Valve is Defective

• Outdoor faucet leaks even when shut off valve is closed
• Valve handle is loose and does not completely stop water flow
• Valve leaks around stem when partially closed
• Corrosion around valve openings and seams
• Dripping increases when outdoor faucet is turned on

Shutting Off the Main Water Supply

Before repairing the leaky shut off valve, you need to turn off the main water supply to the house. This gives you a dry work area for removing and replacing the valve without water spraying everywhere.

Here are the steps for shutting off the main water:

• Locate the main shut off valve near your water meter or front exterior hose faucet.
• Make sure the handle turns freely before closing it. You may need to spray lubricant if stuck.
• Turn the handle clockwise until tight to shut off all water to the home's interior and exterior faucets.
• Open kitchen and bathroom faucets to drain pipes. Water should stop flowing when main is shut off.
• Flush toilets to empty tanks. Turn off automatic ice makers too.

Once the main water supply is fully shut off, you can start servicing the leaky shut off valve. Have towels and a bucket ready to catch drips.

Tips for Turning Off Main Water

• Label the main shut off valve so it's easy to find next time.
• Shut off main when leaving for vacation to prevent leaks.
• Consider installing a quarter-turn ball valve for easier shut off.
• If main valve won't fully close, it likely needs replacing.
• Always close main valve before plumbing repairs.

Removing the Old Shut Off Valve

With the water supply stopped, you can now work on removing the defective outdoor faucet shut off valve. Follow these steps:

• Position bucket under valve to catch drips.
• Use adjustable wrench to loosen packing nut and detach valve from supply line.
• Twist valve counter-clockwise to unscrew it from the faucet shank.
• Pull valve away and inspect interior for wear and mineral deposits.
• Clean faucet shank threads with wire brush to remove debris.

Shut off valves for outdoor faucets commonly have a compression-style design.Rubber washers inside the valve seal against the valve seat to stop water flow when closed. Old and hardened washers often prevent the valve from fully closing.

Valve Replacement Tips

• Take the old valve to the hardware store to match the replacement.
• Consider installing a ball valve for easier quarter-turn shut off.
• Upgrade to a frost-free sillcock valve if dealing with frozen pipes.
• Replace washers if valve body is in good shape.
• Use pipe joint compound for easy tightening.

Installing the New Shut Off Valve

Once you have the replacement shut off valve, it's time to install it. Follow these best practices:

• Wrap valve threads with Teflon tape to prevent leaks.
• Apply pipe joint compound to valve inlet and outlet if not using tape.
• Screw new valve onto faucet shank. Hand tighten and finish with wrench.
• Attach supply line to valve inlet and tighten packing nut.
• Position valve handle for easy access behind appliances.
• Turn main water back on and check for leaks.
• Fully open and close valve several times to seat washers.

Make sure the new replacement valve is positioned so the handle can move freely. Leaving access to shut off water quickly is key for leak prevention.

New Shut Off Valve Tips

• Install a lever-style handle for easy shut off access.
• Quarter-turn ball valves offer smooth and fast water shut off.
• Use metal valves instead of plastic models for increased durability.
• Pick full port valves to avoid flow restriction issues.
• Insulate valve with foam cover to prevent freezing.

Testing for Leaks

The last step is confirming your shut off valve repair fixed the leakage issue.

• Turn main water supply back on and open all faucets.
• Inspect carefully for any drips or water at valve connections.
• Tighten fittings further if small leaks are still occurring.
• Open shut off valve and check outside faucet for proper flow.
• Fully open and close outdoor faucet to test shut off valve operation.

If small drips continue from the shut off valve, the new washers may need further seating. Repeatedly opening and closing the valve can improve the seal. Monitor leaks for a few days to ensure they stop completely after servicing.

• Install freeze-proof sillcock faucets to avoid winter damage.
• Insulate water lines and drain outdoor faucets before freezing temps.
• Replace washers in the faucet if drips develop.
• Lubricate and exercise shut off valves annually.
• Upgrade to 1/4 turn ball valves for reliable water shut off.

Repairing or replacing a leaky outdoor faucet shut off valve is usually a straightforward DIY plumbing project. With the proper steps, you can stop water from dripping out of your exterior spigot and restore full shut off. Just be sure to eliminate the source of leaks before they lead to messy water damage and unnecessary water waste.