Why does my faucet drip after I turn it off?

Because the seal inside is no longer closing fully: on a single-handle faucet that is usually the cartridge, and on a double-handle faucet it is the washer pressing on the seat. Water at the spout means the seal; water underneath means a connection.

How much water does a dripping faucet waste?

Roughly 3,000 gallons a year at one drip per second. If it is the hot tap, you are also paying to heat all of that water.

Can I fix a dripping faucet myself?

Yes, in most cases. Single-handle cartridges and double-handle washers are DIY jobs that need a wrench, a cloth and about ten minutes, plus a shut-off valve under the sink.

When should I replace a faucet instead of repairing it?

When the cartridge is corroded into the body, when the casting is cracked, when the finish has started to flake, or when the model is old enough that replacement parts are no longer made.

How to Fix a Dripping Faucet (Step by Step)

Key takeaways

Dry the faucet and watch: dripping at the spout is the cartridge, dripping underneath is a connection.
One drip a second wastes more than 3,000 gallons a year, and hot water costs you twice.
On a single-handle faucet, the fix is usually a cartridge - pull the clip, lift it out, soak or replace.
On a double-handle faucet, replace the washer and the seat, or it will drip again in weeks.
Stop and call someone if the cartridge is corroded in, there is no working shut-off valve, or parts are obsolete.

A dripping faucet is one of the cheapest things in a house to fix and one of the most expensive to ignore. One drip a second adds up to more than 3,000 gallons a year, and if the water is hot, you are paying to heat it twice. The good news is that most drips come from a worn cartridge or a hardened washer, both of which cost a few dollars and take about ten minutes.

First, work out where it drips

Dry the whole faucet with a towel, then leave it alone for ten minutes and look. Water at the spout means the problem is inside the faucet, in the cartridge or the seals. Water under the sink, on the supply line or around the base, means the problem is a connection. Those are two different repairs, and knowing which one you have saves you from taking apart the wrong thing.

What to replace, and where

A cartridge, a base O-ring, or the supply connection - each one is a different ten minute job.

What the drip is costing you

A slow drip looks harmless because each drop is so small. Count the drops for fifteen seconds and multiply by four to get drops per minute. If that number is around sixty - one per second - you are losing more than 3,000 gallons a year. Fixing it is usually one trip to the hardware store and ten minutes with a wrench.

Fix the common case, a single-handle faucet

Shut off the water at the valves under the sink and open the faucet to release the pressure. Take off the handle - usually a cap or a screw hidden under it - and you will see a retaining clip holding the cartridge in place. Pull the clip, then pull the cartridge straight up. If it resists, do not force it: soak the area with white vinegar for half an hour and try again. Look at the cartridge for white scale or a flattened rubber seat, rinse it in vinegar, and if the rubber is hard or torn, replace it. Reassemble in reverse, turn the water on, and let it run for a minute.

Fix a double-handle faucet

With two handles, the usual culprits are the washer at the bottom of the stem and the seat it presses against. Unscrew the packing nut, pull the stem out, and replace the washer - and the seat if it feels rough or grooved, because a new washer on a damaged seat will start dripping again within weeks. Replace the O-rings while you have it open, since they cost pennies and fail with age.

When it drips under the sink instead

If the drip is below the basin, dry everything, then run the tap and watch. A wet supply nut usually just needs a quarter turn. If that does not stop it, replace the supply line - they are sold as a set and cost less than the water they waste. Water that only appears when the basin is full is the drain flange rather than the supply, which is a different job: the gasket under the strainer or the drain body needs resealing.

Where it drips, and what to do

Where you see water	Likely cause	What to do
At the spout, all the time	Cartridge or washer seat worn	Replace the cartridge or washer and seat
Around the base of the faucet	Base O-ring has hardened	Pull the faucet, replace the O-ring
Under the sink, at the supply nut	Loose nut or worn washer	Tighten a quarter turn, or replace the line
Only when the basin is full	Drain flange or gasket	Reseal the strainer or drain body
From the handle when you turn it	Packing nut or stem O-ring	Replace the packing and the O-rings

Two minutes with a towel tells you which repair you are doing.

And if the flow is weak rather than leaking, that is a different list: weak water pressure at a bathroom sink starts with the aerator. If you decide to replace the faucet while you are in there, the waterfall faucet guide covers what fits and what does not.

When to stop and call someone

Three cases are worth handing over: a cartridge that is corroded into the valve body, a faucet with no working shut-off valves underneath, and a cracked body or a chrome finish that has started to flake. If the faucet is more than fifteen years old and parts are no longer made for it, replacing it is usually cheaper than chasing a discontinued cartridge - and that is the moment to pick a finish that matches the rest of the room, since you are doing the work anyway.

The bottom line

Dry it, find out whether the drip is at the spout or underneath, and start with the cartridge or the washer. Most dripping faucets are a ten minute repair with a couple of cheap parts, and the water you stop wasting pays for them within a month.

If the faucet has reached the point where a cartridge is no longer made for it, the one we make is our matte black waterfall bathroom faucet - but check the cartridge first, because most drips are a ten minute fix.