Symptoms
- Slow drip from the spout when off
- Drip gets worse over months
- One handle harder to shut than the other
- Dripping worse from hot or cold side specifically
Likely causes
- CommonWorn rubber washer at the stemThe washer seals against the valve seat and hardens or wears out with repeated use.
- PossibleCorroded or rough valve seatMineral buildup pits the seat so even a new washer won't seal.
- PossibleWorn O-ring on the stemCauses handle-area leaks more than spout drips.
- Less commonLoose packing nutLets the stem move and seal poorly.
What to do
- Turn off the hot and cold shutoff valves under the sink before starting.
- Open the faucet to release pressure and cover the drain so small parts don't fall in.
- Pry off the decorative cap and remove the handle screw, then lift the handle off.
- Unscrew the packing nut with pliers or a wrench and pull out the stem assembly.
- Remove the screw holding the washer at the bottom of the stem and swap in a matching new washer.
- Check the valve seat for pitting; if rough, resurface it with a seat wrench or plan to replace the seat.
- Reassemble in reverse order, then turn the water back on slowly and check for drips.
- Repeat on the other handle if it shows the same wear, since washers age at similar rates.
Tools and parts
- Adjustable wrench
- Screwdriver
- Needle-nose pliers
- Seat wrench (optional)
Faucet washer assortment kitSearch: “faucet stem washer replacement kit”
Valve seatSearch: “faucet valve seat replacement”
When to call a pro
Call a plumber if the valve seat is badly pitted, the stem is corroded in place, or the leak continues after a washer swap.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.