How Do I Repair Two-Knob Bathtub Faucets?

A leak will grow into a stream unless quickly repaired.

Most leaks on two-knob bathtub faucets are caused by worn washers or cartridges, according to the Alabama Cooperative Extension. The part is quickly replaced if done as soon as the leak appears. Leaks that continue over a long period of time cause a buildup of minerals and sometimes corrosion of metal within the faucet. This complicates the repair, possibly even requiring a new faucet.

Things You'll Need

• Towel
• Thin blade or knife
• Screwdriver
• Wrench or plumbing socket wrench
• Stiff brush
• Nylon scrubbing pad
• Vinegar, optional

Instructions

1. Identify whether the leak is coming from the hot or cold faucet by running the hot water until it is warm, then turning it off. Check the temperature of the leaking water. If you are unable to identify which handle is leaking, you will need to replace both washers or cartridges.

2. Turn off the water to the tub. Most tubs and showers do not have shut-off valves, so turn the water off at the house connection. Turn the hot and cold water knobs to the "on" position, releasing pressure in the line.

3. Place a folded towel in the tub below the work area, covering the drain and protecting the tub from dropped tools or parts.

4. Pop the decorative cover off the handle by sliding a thin knife blade under the cover. It should easily pop off. Remove the screw under the cover that holds the handle on. Set the cover, screw and cover aside, lining up parts in the order they are removed.

5. Unscrew the bonnet nut on top of the valve stem with a wrench. If your handle is set into the wall, you will need a plumbing socket wrench. Remove it and remove the valve stem.

6. Inspect the valve stem for signs of wear, corrosion or mineral deposits. Scrub the metal with a stiff brush and vinegar to remove mineral deposits. Use a nylon scrubber on plastic parts. If corrosion is evident, replace the valve stem.

7. Replace the washer or cartridge at the base of the valve stem with an identical one. Take the part to the hardware store to get the right size.

8. Reset the valve stem in the handle and replace the bonnet nut. Tighten the nut then replace the handle and screw it in place. Replace the decorative cover on the handle.

9. Turn the handles to the "off" position and turn the water supply back on.

Tips & Warnings

• Protect chrome fixtures from tool marks by covering with masking tape before beginning.

References

• Alabama Cooperative Extension: Conserving Water
• City of San Jose: Washerless Faucets
• Denver Water: Repair a Leaky Faucet
• City of San Jose Environmental Services: Repairing Faucet Leaks