Find where the water is coming from
Dry the faucet and the area under the sink with a towel. Then run the water and watch. A drip from the spout when the faucet is off points to the cartridge or seals inside. Water around the handle points to a worn O-ring. Water at the base points to a gasket or a loose body.
If the leak shows only under the sink, the faucet may be fine. Supply lines, shutoff valves, and the drain connection are also common sources. Run a dry paper towel along each connection to find the wet spot.
Common causes and their parts
Most bathroom faucet leaks come down to a short list.
- A worn cartridge or ceramic disc, which causes drips from the spout.
- A dried or cracked O-ring around the handle or the spout base.
- A loose or worn supply line under the sink.
- A leaking shutoff valve or compression nut.
- A corroded pop-up drain assembly in the basin.
Fixing a dripping spout
Close the shutoff valves under the sink, or the main valve if the sink has none. Open the faucet to drain it. Remove the handle, which usually hides a set screw under a small cap. Then pull out the cartridge and compare it to a new one at the hardware store.
Replace the cartridge and any O-rings, apply a thin coat of plumber's grease, and reassemble. Turn the water on slowly and check for leaks. If the faucet is old and parts are hard to find, replacement may cost less than hunting for the part.
Which fix fits which leak
Match the location to the repair.
| Where it leaks | Part to check | Difficulty |
|---|---|---|
| Spout drip | Cartridge or disc | Moderate |
| Around the handle | O-ring or packing | Easy |
| At the base | Gasket or mounting nut | Moderate |
| Under the sink | Supply lines and shutoffs | Easy to moderate |
| Inside the wall | Concealed pipe or valve | Plumber needed, see leak detection |
Supply lines and shutoff valves
The flexible lines that connect the faucet to the wall valves wear out. A line that looks fine can have a pinhole or a loose nut. Replace braided lines that are discolored or kinked, and hand tighten new ones, then add a quarter turn with a wrench.
If the shutoff valve itself drips when you turn it, the valve is worn. Old valves often will not close fully. Replacing the valve is a small plumbing job, and it is worth doing when you replace the faucet so the next repair is easier.
Mineral buildup and your water report
Water in the Sahuarita area comes from your water provider, and providers publish an annual water quality report. Ask yours for the latest one, and test your own tap if you see crust on the faucet. Scale shortens the life of cartridges and clogs aerators, which can look like a leak or low flow.
We do not quote hardness figures for your street, because they vary by provider and over time. Look at your own report and your own fixtures, and ask us if a whole-house option is worth it. Our page on softeners and filtration explains what each system does.
When it is time to replace the faucet
Replace the faucet if the finish is pitted, the body is cracked, or parts are no longer available. A new faucet also gives you a chance to choose a model with a ceramic disc cartridge, which tends to hold up better to scale.
Check how many holes your sink has before you shop, because the faucet must match. If you would rather skip the shopping, our faucet repair page explains how a plumber handles the job.
When to call a plumber
Call if the shutoff valves will not close, if water is leaking inside the wall, or if the cabinet floor is soft or stained. Water that has been leaking for a while can damage the cabinet and flooring, and the repair then grows.
Also call if you cannot find the source. A dripping line behind the wall will not show on the surface, and a quick pressure test or a look with a thermal camera can save you from opening the wall blindly.
A few tools that make the repair easier
You can do most faucet repairs with an adjustable wrench, a set of hex keys, a flat screwdriver, and a small container for screws. A basin wrench reaches the nuts that hold the faucet to the sink from below, where your hands do not fit.
Lay a towel in the basin before you start so a dropped screw does not go down the drain. Take photos as you disassemble the faucet, since the order of parts matters when you put it back together.
How to stop a repair from becoming a bigger one
Use light force on old fittings. Corroded nuts can snap, and a broken shutoff valve turns a small repair into a plumbing call. Soak a stuck nut with penetrating oil and wait before you try again.
If the shutoff valves will not close fully, stop and shut off the main instead. Keep the main valve location in mind so you can reach it quickly. If water keeps coming after you close the valves, call a plumber right away.
Why small leaks still matter
According to the EPA's WaterSense program, the average household's leaks can account for more than 9,300 gallons of water wasted every year. A faucet drip is a small share of that, but it is one of the easiest to fix.
A replacement cartridge from the same manufacturer is the safest match.
Bathroom faucet leak questions in Sahuarita
Why does my faucet drip after I turn it off?
A worn cartridge or seal inside is the usual cause.
How do I stop the leak while I wait for repair?
Close the shutoff valves under the sink. If there are none, close the main valve.
Is the leak under my sink the faucet or the drain?
Dry everything and run the water. If the wet spot shows only when the drain runs, the drain is the source.
Should I fix or replace an old faucet?
Replace it if parts are hard to find or the finish is damaged. Repair it if it is in good shape.
Will a water report tell me about my faucet problem?
It tells you what is in the water, which helps explain scale. It does not diagnose the leak.
Do you fix faucets in Green Valley?
Yes. See the Green Valley page.