Quick answer
A dripping faucet is usually caused by a worn internal part: a rubber washer or O-ring in a compression faucet, a cartridge or its O-rings, worn inlet seals in a ceramic disc faucet, or worn seats and springs in a ball faucet. Shut off the water first. Repair if parts are available; replace if the faucet is corroded or keeps failing.
Why a small drip is worth fixing
The U.S. Environmental Protection Agency's WaterSense program puts numbers on it. A leaky faucet that drips at the rate of one drip per second can waste more than 3,000 gallons per year, which the EPA says is equal to more than 180 showers. The EPA also estimates that fixing easily corrected household leaks can save about 10 percent on a water bill.
A drip usually means an internal seal or valve part has stopped closing tightly.
Step one for any faucet repair: shut off the water
The EPA's guidance is to turn off the water supply before starting any faucet repair. For a bathroom or kitchen sink, that usually means the shutoff valves under the sink. Turn each one clockwise until it stops.
The City of Calgary's water utility adds a few practical points. After shutting off the supply, open the faucet to drain any water left in the lines. Plug the sink drain or cover it with a towel so a small screw or washer does not fall in. Tubs and showers usually lack individual shutoff valves, so the main house valve has to be turned off instead.
If a shutoff valve will not turn, leaks when you try it, or does not stop the flow, stop there. Do not force it. That is a good time to call a plumber.
Find out which kind of faucet you have
The cause of the drip depends on how the faucet is built. The City of Calgary's repair guide describes four common types and how each is identified.
Many faucets fall into one of these groups. If you are not sure, the brand name on the faucet and the model number printed on its box or manual can help you look up the exact parts.
- Washer-type compression faucets have separate hot and cold handles.
- Cartridge faucets have a narrow metal or plastic cartridge inside the faucet body.
- Ceramic disc faucets have a ceramic disc inside a cartridge assembly, in single-handle or two-handle versions.
- Ball-and-cam faucets have a lever attached to a hollow ball that rotates over the hot and cold inlets.
Compression faucets: worn washers and O-rings
A washer-type compression faucet uses a rubber washer at the bottom of the stem. The EPA names worn washers and gaskets as a common cause of drips.
The City of Calgary says the repair is to replace the rubber washer on the bottom of the stem and the stem O-ring. It recommends replacing both sides, hot and cold, even if only one leaks.
When reassembling, the Calgary guide advises greasing the stem threads and not overtightening.
Cartridge faucets: O-rings or the cartridge
In a cartridge faucet, the repair the Calgary guide describes starts with the O-rings on the cartridge.
It says to remove the handle and retainer, pull the cartridge, and replace its O-rings. It also warns to note the orientation of the cartridge, because installing it the wrong way can reverse hot and cold. Take a photo of each step so you can put everything back in order.
Ceramic disc faucets: inlet seals
For a single-handle ceramic disc faucet, the Calgary guide says to replace the three neoprene inlet seals, and if it still leaks, to replace the cartridge with a kit. For a two-handle version, it says to replace the stem O-rings or the whole stem unit.
Be careful to line up the inlet holes correctly when reassembling. The guide notes that the cartridge's three inlet holes must align with the body inlet.
Ball-and-cam faucets: leaks by location
A ball faucet has more parts, so the leak location points to the fix. Per the Calgary guide, a leaky base calls for new body O-rings. A leaky handle may need the adjusting ring tightened or the cam washer replaced. A corroded ball needs replacing. A leaky spout means replacing the valve seats and springs.
Reinstall the ball in its original position and align the cam lug with the notch in the body so hot and cold are not reversed.
Is it a faucet drip, or a leak somewhere else?
Before replacing parts, rule out a hidden leak. The EPA suggests checking your water meter: record the reading, wait two hours without using any water, and check again. Any change suggests a leak somewhere.
Also look for moisture on the outside of pipes, including faucet gaskets and fittings under the sink. A wet cabinet floor or a stain on the ceiling below is a sign the issue is not just the spout.
Repair or replace: the factors to weigh
A repair is usually the better first move when the faucet is in good shape and parts are available. A guide from Mr. Rooter, a plumbing service franchise, lists factors to weigh. These are rules of thumb, not hard limits.
- Age: older faucets are more likely to need replacement than newer ones.
- Corrosion: rust or corrosion on the faucet body suggests a repair will only be temporary.
- Repeat repairs: if the same leak returns, or you have repaired it several times in a year, the valve seat may be damaged.
- Parts: replacement is favored when parts are discontinued or hard to find.
- Cost: if a repair costs close to a new faucet, replacement may be the better value.
- Water use: older faucets can use more water than current models.
What WaterSense faucets offer
If you replace a bathroom faucet, the EPA's WaterSense label is worth looking for. WaterSense labeled bathroom sink faucets use at most 1.5 gallons per minute, which is at least 30 percent less than the standard 2.2 gallons per minute. The EPA says replacing old faucets and aerators saves an average family about 700 gallons per year, and nearly 11,000 gallons over the fixtures' lifetime.
The label involves independent certification. Products must meet criteria for life cycle, lead-free construction, and minimum flow at low water pressure. The EPA says its labeling criteria cover private bathroom sink and bar sink faucets. Kitchen faucets are not covered.
For a quick upgrade, a WaterSense aerator can be screwed onto an existing bathroom faucet. An aerator does not stop a drip, though, so the leaking part still needs attention. The EPA also advises that if repairs do not stop a leak, replacing the fixture with a WaterSense labeled model is an option.
When to call Pyper Plumbing
Many drips are simple repairs, but some are better handed off. Call a plumber if the shutoff valves will not close, if the faucet body is corroded, if the leak returns after a repair, or if water is showing up under the sink or in the wall. Call right away if a fixture is spraying or you cannot stop the water.
Pyper Plumbing repairs and replaces faucets and fixtures, finds and fixes leaks, and responds to plumbing emergencies in Snohomish, Skagit, Whatcom, and Island counties. If you need to stop water now, close the main shutoff valve and call.
Common questions
How much water does a dripping faucet waste?
The EPA says a faucet that drips once per second can waste more than 3,000 gallons per year, equal to more than 180 showers. Actual waste depends on how fast it drips.
Should I turn off the water before fixing a faucet?
Yes. The EPA advises turning off the water supply before faucet repairs. For sinks, use the valves under the sink. Tubs and showers often lack them, so the main house valve may be needed.
Why does the faucet keep dripping after I replaced the washer?
A guide from Mr. Rooter says a leak that returns after a fix may mean a damaged valve seat. That is a reason to bring in a plumber.
Do WaterSense labels apply to kitchen faucets?
No. The EPA says WaterSense labeling criteria exist only for private bathroom sink and bar sink faucets, not kitchen faucets.
Sources
Facts in this guide come from the following references. Local rules and manufacturer instructions can differ, so follow your utility and your equipment manual.
- EPA WaterSense: Fix a Leak Week
- EPA WaterSense: Bathroom Faucets
- City of Calgary: Repairing Faucets
- Mr. Rooter Plumbing: Faucet Repair or Replacement
This guide is general information, not a substitute for an on-site inspection. If you smell natural gas, leave the building and call 911 or your gas utility. Pyper does not perform gas line work.
