Plumbing·Leaks

How to fix a leaking faucet (2026)

Verified from sources

Quick Answer

Most leaking taps are fixed by shutting off the water, taking the tap apart, replacing the worn sealing part inside, then reassembling and testing. The exact part that fails depends on the tap type: a rubber washer is common in traditional compression taps, while ceramic disc, cartridge, or O-ring faults are common in mixer and quarter-turn taps. Identifying the tap type before buying parts is the key to a clean, lasting repair.

Overview

A dripping tap is usually caused by wear in the internal parts that control water flow. In older taps, the usual culprit is a worn washer on the valve. In newer mixer taps, the problem is often a cartridge, ceramic disc assembly, or perished O-ring. The repair is usually straightforward if you work methodically: isolate the water supply, protect the sink plughole, remove the handle, dismantle the valve or cartridge assembly, inspect the sealing parts, replace worn components like-for-like, then reassemble and test slowly. The most important parts of the job are identifying the tap type correctly and keeping parts in order as you remove them. Many leaks get worse because the wrong replacement part is fitted, threads are damaged by forcing them, or the water is not fully isolated before disassembly. Cleaning away limescale and debris also matters, because a new washer or cartridge may still leak if the seating surfaces are dirty or damaged. This guide covers the common repair path for household basin, bath and kitchen taps. If the tap body is cracked, heavily corroded, seized solid, or still leaks from the base or spout after replacing serviceable parts, replacement of the whole tap or help from a plumber is usually the better option.

Who this is for

Homeowners, tenants with permission, and general DIYers dealing with a dripping or lightly leaking basin, bath or kitchen tap.

What you’ll need

Flat and cross-head screwdrivers
Adjustable spanner or suitable spanners
Allen key set for taps with grub screws
Cloth or towel to protect tap finish
Sink plug or rag to block the waste
Replacement washer, O-ring, cartridge or ceramic disc assembly matched to the tap
Plumber's grease suitable for tap seals, if recommended by the manufacturer
Small container or tray for screws and parts
Cleaning cloth and a non-abrasive way to remove scale and debris
Manufacturer instructions or parts diagram if available

Before you start

Check where the leak is coming from: the spout, around the handle, from the base, or from supply pipe connections underneath. Turn the tap off normally and see whether it still drips from the spout; that usually points to an internal sealing problem. Find and test the isolation valves under the sink if fitted, or locate the main stop valve if not. Take a clear photo of the tap before and during disassembly so you can match parts and reassemble in the right order. If the tap is old, unusual, or from a specific brand, look for the manufacturer's exploded parts diagram before buying spares.

Step-by-step

1
Identify the tap type and leak point
Work out whether you have a traditional compression tap, a quarter-turn ceramic disc tap, or a mixer tap with a cartridge. Remove any decorative cap only if needed to inspect the fixing arrangement. Also confirm whether the leak comes from the spout, the handle area, the base of the tap, or the pipe connections below.
Why: Different taps fail in different ways and use different replacement parts. Correct diagnosis stops you buying the wrong parts or dismantling parts that are not causing the leak.
2
Shut off the water and prepare the area
Close the local isolation valves if fitted, or shut off the main water supply. Open the tap to relieve pressure and confirm the flow has stopped. Put the plug in the sink or block the waste with a rag, and lay a cloth around the tap to protect surfaces.
Why: Isolating the water prevents flooding and pressure-driven spray when the tap is opened up. Blocking the waste stops small screws, clips and washers disappearing down the drain.
3
Remove the handle and expose the working parts
Take off the decorative cap if present, undo the handle screw or loosen the grub screw, and lift off the handle. Remove any cover shroud to expose the valve head, cartridge retaining nut, or ceramic disc assembly. Keep each part in order.
Why: Taps often have layered trim pieces that conceal the actual serviceable component. Keeping the order of parts makes reassembly much easier and reduces the chance of trapping or misaligning seals.
4
Take out the faulty valve, cartridge or seal
Use the correct spanner to loosen and remove the valve head or retaining nut, then lift out the cartridge or valve assembly. Inspect the washer, O-rings, ceramic disc unit and the seat area inside the tap body. Replace visibly worn, split, flattened or hardened seals with matching parts, or replace the whole cartridge if that is how the tap is designed.
Why: The leak usually comes from a sealing surface no longer closing properly. Replacing only the failed part can restore a watertight seal, but only if the replacement matches the original design.
5
Clean the seating surfaces and check for damage
Wipe away scale, grit and old grease from the tap body and the removed parts. Check for cracking, deep scoring, heavy corrosion, or obvious damage to the seat and threads. If the tap uses O-rings, apply a small amount of suitable plumber's grease only if the manufacturer allows it.
Why: Debris and limescale can stop new seals from seating properly, causing continued dripping. Damage to the body or seat means a simple seal replacement may not solve the problem.
6
Reassemble carefully without forcing parts
Refit the valve or cartridge squarely in the correct orientation, then reinstall retaining parts, shrouds and the handle. Tighten fittings firmly but do not overtighten. If anything resists badly, stop and check thread alignment and part orientation.
Why: Cross-threading, misalignment and overtightening can damage the tap body, distort seals and create new leaks. A correctly seated part does not normally need excessive force.
7
Restore the water slowly and test
Turn the isolation valves or main supply back on slowly. Run the tap, then turn it off and watch for dripping from the spout, seepage around the handle, and leaks from joints below the sink. If needed, gently nip up the relevant retaining part and test again.
Why: Restoring pressure slowly reduces shock to the repaired parts and helps you spot any leak path clearly. Testing both on and off confirms whether the seal is holding under normal use.

Why this works

A tap controls water by pressing or aligning sealing surfaces. When a washer, O-ring, cartridge or ceramic disc assembly wears out, water can pass even when the tap is closed. Replacing the worn sealing component and cleaning the contact surfaces restores the barrier that stops the flow.

Common mistakes to avoid

Buying replacement parts before identifying the tap type and exact internal part
Forgetting to isolate the water supply before dismantling the tap
Letting small screws or clips fall down the plughole
Using too much force and damaging chrome, threads or retaining nuts
Reusing worn seals because they look 'almost fine'
Skipping cleaning, so grit or limescale prevents the new part from sealing
Assuming all drips come from the spout when the real leak is at the base or supply connection

Troubleshooting

The tap still drips from the spout after replacing the washer or cartridge

Recheck that the replacement part matches exactly and is seated the right way round. Clean the seat again and inspect the tap body for damage; if the seat or body is worn, the whole tap may need replacement.

Water leaks around the handle when the tap is on

Inspect and replace the spindle or cartridge O-rings and make sure the gland or retaining section is assembled correctly.

The retaining nut will not move

Protect the finish, use the correct tool, and apply steady pressure rather than jerking. If corrosion has effectively seized the part, replacing the tap may be more practical than forcing it.

Leak appears underneath the sink after the repair

Dry everything fully and identify whether the leak is from the tap tail connection, flexible hose, or the tap body itself. Tighten only the correct connection carefully, and replace any failed sealing washer according to the fitting design.

The tap is stiff to turn after reassembly

Check that parts are aligned correctly and not overtightened. If the manufacturer permits it, apply suitable grease sparingly to the relevant seal or moving point.

Compare your options

Replace washer or O-ring only

Best for: Traditional taps or simple leaks where the failed seal is obvious and the rest of the tap is in good condition

Pros: Cheapest repair path, minimal parts needed, less waste

Cons: Will not fix damaged seats, worn cartridges or cracked bodies

Replace the full cartridge or ceramic disc assembly

Best for: Mixer taps and quarter-turn taps designed with replaceable internal cartridges

Pros: More likely to solve the leak in one repair, avoids guessing which internal seal has failed

Cons: Parts must match exactly, branded cartridges can be harder to identify

Replace the entire tap

Best for: Old, seized, corroded, cracked or repeatedly leaking taps

Pros: Resolves multiple worn parts at once, can be easier than fighting a badly degraded tap

Cons: More work, usually higher overall cost, may involve awkward access under the sink

Option	Best for	Pros	Cons
Replace washer or O-ring only	Traditional taps or simple leaks where the failed seal is obvious and the rest of the tap is in good condition	Cheapest repair path, minimal parts needed, less waste	Will not fix damaged seats, worn cartridges or cracked bodies
Replace the full cartridge or ceramic disc assembly	Mixer taps and quarter-turn taps designed with replaceable internal cartridges	More likely to solve the leak in one repair, avoids guessing which internal seal has failed	Parts must match exactly, branded cartridges can be harder to identify
Replace the entire tap	Old, seized, corroded, cracked or repeatedly leaking taps	Resolves multiple worn parts at once, can be easier than fighting a badly degraded tap	More work, usually higher overall cost, may involve awkward access under the sink

Alternatives

Take the removed cartridge or valve assembly to a plumbing merchant to match the part accurately
Use the tap manufacturer's spare-parts service if the brand is known
Replace the whole tap if spare parts are unavailable or the body is damaged

Pro tips

Take photos at each stage so you can reverse the disassembly confidently
Lay parts out in order from left to right as you remove them
Wrap a cloth around visible chrome before using tools nearby
If both hot and cold taps are the same age, consider buying spare seals for both while the water is off
If local isolation valves do not fully stop the flow, use the main stop valve instead

Safety notes

Make sure the water supply is fully isolated before opening the tap body
Be careful around hot water supplies; let very hot water run out and cool before dismantling
Use tools that fit properly to reduce slipping and hand injuries
Do not use excessive force on fragile ceramic or plated parts
Keep small parts away from children and pets

Legal & regulatory notes

Rules vary by country and sometimes by tenancy agreement. In rented property, check whether you are allowed to repair plumbing fittings yourself. If the work involves altering fixed pipework rather than servicing a tap, local plumbing rules or landlord approval may apply.

What this guide does not cover: This guide covers common household tap leaks and basic internal repairs. It does not cover concealed valves, specialist commercial fittings, major pipework leaks, or model-specific disassembly for every tap brand.

Cost considerations

A simple seal repair is usually the lowest-cost option if the correct part is easy to obtain. Costs rise when a branded cartridge is needed or when corrosion turns a repair into a full tap replacement. If repeated repairs have failed, replacing the tap can be more economical than continued trial-and-error with parts.

Prefer to hire a professional?

If this job is beyond a confident DIY — or the work needs to be done by a licensed professional — you can find a verified plumber through Trade Directory (tradedirectory.co.nz), New Zealand's directory of real, verified trade businesses. Compare local tradespeople, read their details and request quotes before you commit.

Find a plumber on Trade Directory

Frequently asked questions

How do I know whether I need a washer or a cartridge?+

Traditional taps that need several turns to open often use a washer. Quarter-turn and many mixer taps usually use ceramic disc or cartridge assemblies. If unsure, remove the handle and look up the tap brand's parts diagram.

Can I fix a dripping mixer tap myself?+

Often yes, if you can isolate the water and obtain the correct cartridge or seals. The key is matching the replacement part exactly and reassembling it in the right orientation.

Why is my tap still dripping after I changed the washer?+

The wrong part may have been fitted, the seat may be dirty or damaged, or the tap may actually use a different internal mechanism. Persistent dripping can also mean the tap body is too worn for a simple washer change.

Do I need sealant or PTFE tape inside a tap repair?+

Usually you should follow the tap manufacturer's guidance. Many internal tap repairs rely on purpose-made washers, O-rings or cartridges rather than thread sealants. Using the wrong sealant can make things worse.

When should I stop and call a plumber?+

Call a plumber if the isolation valves fail, the tap is seized solid, the body is cracked, the leak is from hidden pipework, or you cannot identify the correct replacement part.

Sources & references

Guidance on this page is traced to documented sources. Last checked 24 September 2026.

British Standards Institution - Water fittings and materials directory · industry
Supports the need to use suitable plumbing fittings and manufacturer-aligned parts and instructions rather than improvised components.
Hansgrohe - Service and spare parts · manufacturer
Supports identifying the exact tap model and using the correct spare parts diagram for cartridges, seals and reassembly.

The basic repair method changes little, though tap internals and manufacturer-specific parts differ by model.