How to fix a dripping tap
A tap that drips from the spout after you turn it off almost always has a worn internal part. On a traditional tap that takes several full turns to close, it is the rubber washer. On a quarter-turn tap that goes from off to full flow in half a turn or less, it is the ceramic disc cartridge. To fix it, turn off the water at the isolation valve under the sink or at the stopcock, open the tap to drain it, take off the handle, unscrew the headgear or cartridge, and fit a matching new washer or cartridge. If the tap leaks from the base or the handle rather than the spout, the fault is usually an O-ring instead.
Loyal Plumbers · Updated
Discuss your plumbing workWhere the drip comes from tells you the fault
Before you buy anything, watch the tap for a minute. Where the water appears narrows the job down to one part, and saves you taking apart a tap that only needs a seal.
A drip is worth fixing promptly. It wastes water, a hot tap drip wastes heated water too, and the constant wet leaves limescale and staining in the basin. A worn washer also tempts people to overtighten the tap, which damages the seat underneath and turns a cheap repair into a new tap.
| Where it leaks | Tap type | Usual cause |
|---|---|---|
| Drips from the spout when off | Traditional, several turns to close | Worn rubber washer, or a worn seat |
| Drips from the spout when off | Quarter-turn or lever | Worn or dirty ceramic disc cartridge |
| Water round the handle when running | Either | Worn O-ring or gland packing on the spindle |
| Water at the base of a swivel spout | Kitchen mixer | Worn O-rings on the spout |
| Water under the sink, not at the tap | Any | Flexible hose or connection leaking, not the tap itself |
What you need
Take the old part with you to the plumbers' merchant or DIY shop. Washers come in standard sizes, but cartridges vary by manufacturer in length, spline count and thread, and the only reliable way to match one is to compare it side by side.
- A flat screwdriver for the isolation valve and handle screw
- An adjustable spanner, plus a cloth to protect chrome finishes
- A replacement washer (usually 1/2 inch for basin taps, 3/4 inch for bath taps) or a matching cartridge
- Silicone grease for O-rings, and a small brush for limescale
- A plug in the plughole, so small screws cannot fall into the waste
Turn the water off first
Look under the sink for a small isolation valve on each pipe to the tap. It has a slot you turn a quarter turn with a flat screwdriver so the slot sits across the pipe. If there is no valve, or it does not stop the flow, turn off the main stopcock, which is usually under the kitchen sink or where the supply enters the building. For a hot tap fed from a tank in the loft, you may need to turn off the valve on the pipe from the cylinder instead.
Open the tap fully and let it run until it stops. If it keeps running after a couple of minutes, the water is not properly off. Do not start taking the tap apart until the flow has stopped completely.
If the stopcock is stiff, do not force it with a wrench. Old stopcocks can snap or start leaking at the gland when forced. Our guide on a stopcock that will not shut off covers the safe options.
Replacing a washer on a traditional tap
Older pillar taps and many bath taps use a rubber washer that is squeezed against a seat inside the tap body when you close it. Over time the rubber hardens, splits or wears a groove, and water gets past.
- Prise off the decorative cap on the handle (often marked hot or cold) and undo the screw beneath it. Pull the handle off.
- If there is a metal shroud over the body, unscrew it by hand or with a cloth-wrapped spanner.
- Hold the tap body firmly with one hand so it cannot twist on the sink, and undo the large headgear nut with the spanner.
- Lift out the headgear. The washer sits on the bottom, held by a small nut or simply pressed onto a button.
- Fit the new washer the same way round, then refit the headgear and tighten it firmly, but do not force it.
- Refit the shroud and handle, turn the water back on slowly and test the tap.
Replacing a ceramic disc cartridge
Quarter-turn taps and most modern mixers do not have a washer. Two ceramic discs with holes in them slide over each other to open and close the flow. They last a long time, but grit or limescale can score the discs, and then the tap drips however firmly you turn it.
The process is similar. Remove the handle, undo the cartridge with a spanner while holding the tap body steady, and note which way round it sits, because hot and cold cartridges on some taps turn in opposite directions. Sometimes cleaning the discs and the rubber seal at the bottom with warm water is enough. If the discs are chipped or scored, fit a matching replacement.
If you cannot find a matching cartridge, or the tap is old and worn in other places, it can make more sense to replace the whole tap. Our guide on replacing the cartridge or the whole tap sets out how to decide.
If it still drips after a new washer
When a traditional tap keeps dripping with a brand new washer, the seat in the tap body is usually pitted or worn. A seat can sometimes be recut with a reseating tool or covered with a plastic seat insert, but it depends on the tap. On a quarter-turn tap, a drip after a new cartridge usually means the wrong cartridge, a missing seal at its base or debris in the body.
Stop at this point if the headgear nut will not move, the tap body is loose on the sink, or you can see corrosion or cracking. Forcing a seized nut is the usual way a simple washer job ends with a sheared tap and no water to the kitchen.
Getting a plumber to fix it
Call a plumber if the water will not isolate, the stopcock is seized, the headgear is stuck, the tap keeps dripping after a new part, or water is leaking under the sink or into a cupboard. Leaks from flexible tap hoses under the sink can fail suddenly, so do not leave those.
Loyal Plumbers repairs and replaces taps across London and everywhere inside the M25, 24 hours a day, with 10 vans on the road. Our call-out is £60. Tell us the tap type, where the water is coming from and whether you have isolation valves, and a photo of the tap helps the engineer bring the right parts.
Common questions
- Can I fix a dripping tap without turning off the water?
- No. Opening the headgear or cartridge with the supply on will release water at mains pressure. Turn it off at the isolation valve or stopcock first.
- How do I know if my tap has a washer or a cartridge?
- If the handle turns several times from off to full flow, it has a washer. If it goes from off to full in a quarter or half turn, it has a ceramic cartridge.
- Why does my tap drip after I turn it off hard?
- Overtightening squashes a worn washer temporarily, but it wears out faster and can damage the seat. Replace the washer instead of turning harder.
- Is a dripping tap an emergency?
- A slow drip from the spout is not. Water leaking under the sink, from a hose or into a cupboard is more urgent, because it can damage the unit and floor.
Sources and further reading
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