How to Fix a Compression Faucet

Before a hot-water scalding motivated Al Moen to invent the single-handle mixing faucet in the mid 1900s, all faucets were compression faucets. Today most outdoor faucets, as well as those in laundry and utility rooms, still have compression valves. The valve seat and stem in a compression faucet are threaded and turning the handle forces a washer onto the valve inlet to stop the flow of water. When a compression faucet leaks, it's usually because the washer is worn out. You can fix most leaks in a few minutes.

• 1

  Turn off the water to the faucet by either shutting off a valve in the water supply line or, if you can't find one, shutting off the main water to the house. Open the faucet and let water drain out.

• 2

  Unscrew the screw holding the handle to the valve stem with a Phillips screwdriver and remove the handle. For outdoor spigots and hose bibs, you may not need to do this, as long as you have access to the nut that holds the valve stem in place. Many kitchen and bathroom faucets, though, have handles that prevent this access.

• 3

  Unscrew the nut that holds the valve stem in place with an adjustable wrench. Grip the nut with the wrench and turn it sharply counterclockwise to loosen it, then unscrew and remove it. If the nut is stuck, spray some thread lubricant up into the nut from below and give it 5 minutes to work, then try unscrewing it again.

• 4

  Unscrew the valve stem by turning it counterclockwise and lift it out, then turn it over. Unscrew the Phillips screw holding the washer to the end of the stem and remove it. To purchase a replacement, take the entire valve stem to the hardware store rather than the old washer, which is probably too worn to use as a reference.

• 5

  Clean out the valve seat with a wire brush to remove mineral deposits. If it is worn or cracked, unscrew it with a seat wrench and take it to a machinist to have it re-ground, or replace it with a new one.

• 6

  Screw in the new or retooled valve seat if you took it out. Insert the valve stem with the new washer and tighten it down about halfway by turning it clockwise. Screw on the retaining nut. Replace the handle if you took it off. Tighten the handle to close the faucet. Turn on the water and check for leaks.