How to Replace the Shut-Off Valve Under a Sink


The water to a kitchen or bathroom sink is supplied through small copper or flexible neoprene tubes from a small control valve, called a stop or shut-off valve, under the sink. There are two basic types, straight stops and angle stops, and these valves normally remain on and are seldom closed, functioning maintenance-free for years. Aging stop valves can begin to leak as tap water mineral deposits build up or the internal seals degenerate. Replacement of these inexpensive valves is a simple repair.

Things You'll Need

  • Adjustable wrench
  • Bucket or small container
  • Emery cloth
  • Teflon thread tape
  • Straight or angle stop valve
  • Turn the water supply off to the stop valve by closing the main gate valve. This main valve is typically located on the exterior of the house.

  • Open the sink's faucets to drain water from the fixture and release siphon pressure in the water line.

  • Position a bucket or container beneath the stop valve being replaced to capture the small amount of water in the lines when the water line from the faucet is disconnected.

  • Use an adjustable wrench to loosen the small hex nut that connects the water line to the sink faucet.

  • Loosen the larger hex nut at the base of the stop valve, turning it clockwise until it is free of the valve's threads.

  • Remove the stop valve from the copper water line by pulling it forward. Remove the brass compression ring around the copper water line to free the large hex-head nut.

  • Clean any corrosion or mineral buildup from the exposed copper water line with a piece of emery cloth.

  • Push the new stop valve's large hex nut onto the copper waterline, with the opening toward you, then slide the new brass compression ring over the copper waterline.

  • Wrap two or three full layers of Teflon thread tape clockwise around the threaded sections of both the large and small hex nut connections.

  • Slip the new stop valve onto the copper waterline and tighten the large hex nut to finger-tight, making certain the water line connection is positioned straight up. Use the adjustable wrench to tighten the hex nut.

  • Connect the waterline from the sink faucet to the smaller connection hole and tighten the hex nut.

  • Turn the control knob on the new stop valve counterclockwise to the fully open position. Open the sink's faucet.

  • Open the main gate valve to turn the house water supply back on.

  • Check the new stop valve's connections for leaking, and tighten the hex nut connections as necessary. Do not over-tighten.

Related Searches

  • Photo Credit older valve image by Aleksandr Ugorenkov from
Promoted By Zergnet


You May Also Like

Related Searches

Check It Out

22 DIY Ways to Update Your Home on a Small Budget

Is DIY in your DNA? Become part of our maker community.
Submit Your Work!