A dripping tap is one of those jobs that is easy to put off and surprisingly satisfying to finish. Left alone, a steady drip wastes a significant amount of water over the course of a year, and on a water meter that waste shows up directly on your bill. The good news is that most drips come down to one small worn part, either a rubber washer that costs very little or a ceramic cartridge you can swap in under an hour.

This guide works through the job in the right order. First you will work out which type of tap you have, because that decides which fix applies. Then you will turn the water off safely, carry out the repair, and test it properly before you put everything back.

Why a Tap Drips: Diagnose It by Tap Type

Almost every dripping tap fails for one of four reasons: a worn washer, a failed ceramic cartridge, limescale build-up, or a damaged valve seat. Which one you are dealing with depends on the tap itself, and there is a simple test.

Turn the tap handle. If it needs a full turn or more before the water stops, you have a traditional tap, sometimes called a compression tap. Inside it, a rubber washer is pressed down onto a metal seat every time you close the tap. That washer hardens, cracks and splits with age, and once it no longer seals flat, water creeps past and drips from the spout.

If the handle only needs a quarter turn or a half turn, you have a modern tap with a ceramic disc cartridge, common on mixer taps and monobloc kitchen taps. These do not use a washer at all. The seal comes from two ceramic discs sliding over each other, and drips usually mean the cartridge is worn, cracked, or fouled with limescale and grit.

One more check before you start: where is the water coming from? A drip from the spout points to the washer or cartridge. A leak from around the base of the handle or the tap body usually means a worn O-ring or gland packing instead, which is covered later in this guide. Getting this diagnosis right first saves you dismantling the wrong part.

What You Will Need

Gather everything before you touch the tap, because once the water is off you do not want to be hunting through drawers.

• Adjustable spanner
• Flathead and crosshead screwdrivers
• Allen keys (some modern handles are fixed with a small grub screw)
• Replacement washers in assorted sizes, or the correct replacement cartridge for your tap
• Replacement O-rings (often sold in the same assorted packs as washers)
• An old towel or cloth to protect the sink and tap finish
• A plug for the sink, so small screws and washers cannot escape down the plughole
• White vinegar and an old toothbrush if limescale is present
• PTFE tape (optional, useful when refitting some threaded parts)

If you are buying a cartridge, take the old one out first and take it to the shop or match it carefully online. Cartridges are not universal: they differ between hot and cold, and between manufacturers. A washer, by contrast, is a standard part that costs very little, which is why the traditional tap fix is one of the cheapest repairs in the house.

Turn Off the Water and Drain the Tap

Never skip this step, and never rely on just closing the tap itself.

Look under the sink or basin for an isolation valve on the pipe feeding the tap. It is usually a small valve with a slot for a flathead screwdriver. Turn the slot so it sits across the pipe rather than along it, and the water to that tap is off.

If there is no isolation valve, turn the water off at the stopcock instead. In most UK homes the stopcock is under the kitchen sink, though it can also be in a downstairs cupboard, by the front door, or in the cellar. Turn it clockwise until it stops. If your stopcock has not moved in years and is seized solid, do not force it; that is a job to sort separately, and it is worth knowing where yours is before you ever have an emergency.

With the water off, open the dripping tap fully and let the water in the pipe drain out. Open the tap furthest from it as well if you are working on the mains-fed side, so the pipe empties properly. Put the plug in the sink now, before any small parts come off.

Fix 1: Replace the Washer on a Traditional Tap

This is the most common fix in UK homes, and it takes most people 30 to 45 minutes the first time.

1. Remove the tap cover. Many traditional taps have a cap on top of the handle, sometimes marked H or C, which prises off with a flathead screwdriver. Underneath you will find a screw. Some handles are held by a screw at the side or underneath instead.
2. Undo the screw and lift the handle off. If it is stuck, wiggle it gently rather than levering hard against the tap body.
3. Unscrew the headgear. The brass valve assembly beneath the handle unscrews from the tap body with your adjustable spanner, turning anti-clockwise. Wrap the cloth around chrome parts first so the spanner does not mark the finish. If the whole tap starts to rotate, hold the tap body steady with your other hand or a second spanner.
4. Find the washer. At the bottom of the headgear there is a small stem called the jumper, and the washer sits on it, held by a tiny nut or simply pushed over a button. Remove the old washer. It will usually look flattened, cracked or misshapen, which confirms your diagnosis.
5. Fit the new washer. Push the replacement on firmly, reusing or replacing the small retaining nut if there is one. The new washer should sit flat and snug.
6. Check the O-ring. There is usually a rubber O-ring on the headgear thread or stem. If it looks perished, replace it now while everything is apart, as this is the part that stops leaks around the spindle when the tap is open.
7. Reassemble in reverse. Screw the headgear back in firmly but do not overtighten it, refit the handle and screw, and push the cap back on.

That is the whole repair. If your tap is old and the washer has been replaced before without success, look at Fix 3 below before you reassemble, because the seat the washer presses against may be the real problem.

Fix 2: Clean or Replace the Ceramic Cartridge in a Mixer Tap

Quarter-turn taps do not have a washer to change. Their seal lives in a self-contained cartridge, and the honest truth is that replacement is usually more reliable than repair.

1. Turn the water off and drain the tap, exactly as described above. Mixer taps often have two isolation valves, one for hot and one for cold.
2. Remove the handle. On lever taps there is usually a tiny grub screw under the lever or behind a small plastic cap, loosened with an Allen key. Lift the handle away.
3. Expose the cartridge. There may be a decorative shroud or a large retaining nut holding the cartridge in place. Unscrew the nut with your spanner.
4. Pull the cartridge out. Note its orientation before you remove it; many cartridges have locating lugs that only fit one way. Take a photo on your phone if it helps.
5. Try cleaning first if the cartridge looks intact. In hard water areas, limescale and grit on the ceramic discs are a common cause of dripping. Soak the cartridge in a bowl of white vinegar for an hour, rinse it, work the mechanism gently, and refit it. This fixes a fair number of cartridge drips for the cost of a cup of vinegar.
6. If the drip continues, or the cartridge is cracked or stiff, replace it. Fit the new cartridge in the same orientation, replace the retaining nut without overtightening, and refit the handle.

Because cartridges vary so much, the single most common mistake with this fix is buying the wrong replacement. Match the old cartridge’s length, diameter and spline count, or take it to a plumbers’ merchant, where staff identify cartridges every day.

Fix 3: The Valve Seat and Leaks Around the Handle

Two less common causes are worth knowing about, because they explain the taps that keep dripping after a new washer.

The valve seat is the brass surface inside the tap body that the washer presses against. If it becomes pitted or scored, often after years of a washer being left to fail, even a perfect new washer cannot seal against it. Minor damage can be cleaned up with a tap reseating tool, a small grinding tool that sits in the tap body and re-cuts a flat seat. These are inexpensive and widely available. A badly damaged seat, however, usually means the tap itself is at the end of its life.

Leaks around the base of the handle, which appear when the tap is open rather than as a drip from the spout, come from the gland or O-ring around the spindle. On older taps the gland nut can sometimes be tightened a fraction to compress the packing and stop the weep. On most taps, replacing the O-ring while you have the headgear out for a washer change is the permanent answer, which is why it is always worth doing at the same time.

Turn the Water Back On and Test Properly

Turn the isolation valve or stopcock back on slowly. Leave the tap you have been working on open for the first few seconds so any air and loose debris flush through, then close it.

Now watch the spout for a full minute. A successful repair means no drip at all once the tap is closed with normal hand pressure. If you have to force the handle hard to stop a drip, something is still wrong, and forcing it will destroy a new washer quickly.

Check under the sink as well. Run your hand around the tap connections and the isolation valve and feel for moisture. A repair that is dry at the spout but weeping underneath will cause slow damage inside the cupboard or cabinet that you may not notice for months. If you find a wider pattern of leaks, staining or corrosion under there, it is one of the clearer signs that you need to contact a plumber rather than keep patching individual parts.

Finally, remember why the job was worth doing promptly. A tap that drips once a second wastes a surprising volume over a year, and sorting small leaks like this is one of the easiest water-saving wins in the house, as our guide to eco-friendly solutions for fixing leaks and conserving water explains. If the tap feeds from a hot water system, you are also paying to heat water that goes straight down the plughole, so the saving is bigger than it looks. If your system is older and you are weighing up bigger work, our water heater installation guide covers what replacement involves.

Still Dripping? What a Plumber Costs and When to Call One

Call a plumber if any of the following apply: the drip continues after a new washer and a seat check; the tap body itself is cracked or corroded; the stopcock is seized so you cannot isolate the water; or the leak is coming from a joint or pipe rather than the tap mechanism.

As a rough budgeting guide, fixing a dripping tap is a small job for a plumber and is usually charged as a minimum first-hour call-out, which commonly falls somewhere around £50 to £90 outside London depending on your area and the time of day, with the washer or cartridge itself costing very little on top. Emergency and evening call-outs cost more. Always confirm the minimum charge before you book, and if the tap is old, ask for the price of replacing the whole tap at the same time, because on a worn-out tap a replacement can work out better value than a second repair visit.

For a straightforward tap, though, this is a job most homeowners can finish themselves in under an hour, for the price of a washer. It is a good first plumbing repair: the water is easy to isolate, the parts are cheap, and the diagnosis skills you learn here, working out which component has actually failed before changing anything, apply to almost every other fix in the house.

Frequently Asked Questions

How long does it take to fix a dripping tap?

Most people finish in 30 to 60 minutes, including turning the water off and testing. A traditional washer change is usually the quickest. A cartridge replacement takes a little longer if you need to source the correct cartridge first.

Why is my tap still dripping after changing the washer?

The three usual reasons are a pitted valve seat that the new washer cannot seal against, the wrong size washer, or, on a quarter-turn tap, a failing cartridge rather than a washer problem at all. Work back through the diagnosis at the top of this guide and check which tap type you actually have.

Can a dripping tap increase my water bill?

Yes, if you are on a water meter. An unmetered home will not see a direct charge, but the waste is the same. If the dripping tap is on the hot side, you are also paying to heat the wasted water.

Do I need a plumber to change a tap washer?

No. Changing a washer is a standard DIY job and does not require any certification, as long as you can turn your water off safely. Work on gas appliances is completely different and must always be left to a Gas Safe registered engineer.

What size washer does my tap need?

Tap washers come in a few standard sizes, most commonly 3/8 inch and 1/2 inch in older UK taps. The simplest approach is to remove the old washer and take it with you when you buy the replacement, or buy an assorted pack, which covers almost every domestic tap and costs very little.

Is it better to repair or replace a dripping tap?

Repair it if the tap body is sound and the fault is a washer, cartridge or O-ring. Replace it if the body is corroded, the seat is badly damaged, or the tap has needed repeated repairs. Modern replacement taps are not expensive, and a new tap ends the cycle of small fixes.