Why does my tap only drip sometimes and not constantly?

An intermittent drip, rather than a constant one, often points to a partially worn washer or cartridge that's still mostly sealing correctly, or to slight changes in water pressure affecting how well a borderline seal holds. It's usually still worth fixing, since intermittent drips tend to become constant ones over time as the part wears further.

How do I know if my tap has a washer or a ceramic disc cartridge?

Feel is the quickest test: a handle that takes a full turn to open almost always means a washer, while a lever with hardly any resistance to it almost always means a ceramic disc cartridge. Our guides on replacing a tap washer and what a ceramic disc tap is go into each mechanism in full.

Is a dripping tap actually worth fixing, or can I just leave it?

It's worth fixing sooner rather than later. A slow drip can waste several litres of water a day, which adds up on a water meter, and dripping water often leaves limescale or rust staining on the sink or bath below over time. The fix itself is usually inexpensive, so there's little reason to put up with it long term.

What if I can't find a replacement cartridge for my exact tap?

Check the tap manufacturer's website first, as most keep spare parts available for years after a model is discontinued. A plumbers' merchant may also be able to suggest a compatible universal alternative if the exact cartridge is no longer available. Failing that, it's usually more practical to replace the whole tap.

Can I fix a dripping tap without turning off the water?

No, not safely. Any tap repair that involves removing the handle or headgear requires the water supply to that tap to be isolated first, otherwise you'll be dealing with a constant flow of water the moment anything is loosened. Always isolate the supply and release pressure by opening the tap before starting any repair.

What size O-ring do I need for a leaking spout?

There's no single universal size, since it depends on your tap's spout spigot diameter. The most reliable approach is to take the old O-ring to a plumbers' merchant to match it in person, or buy a multi-size O-ring kit that covers the common sizes used in domestic taps.

Can I use petroleum jelly instead of silicone grease on an O-ring?

It's better to use a proper food-safe silicone grease if you can get hold of one. Petroleum-based products like Vaseline can degrade rubber O-rings over time, which shortens the life of the very part you've just replaced.

Why does my spout only leak when I turn it?

This is the classic sign of a worn O-ring, since the seal is under the most stress exactly when the spout is moving. A spout that leaks constantly regardless of position more often points to a seal at the tap's base instead, which is more a case for reseating the tap properly, covered in our guide on installing a tap yourself.

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How to Fix a Dripping Tap

Most drips come down to one of a small handful of simple, fixable causes, whether you have a washer tap or a ceramic disc one

Thomas RichardEditor, The Tap Guide

Updated 20 July 2026 · 4 min read

In this article

Why taps drip
Tools you'll need
First, work out which type of tap you have
Fixing a traditional washer tap
Fixing a ceramic disc tap
Fixing a leaking spout (O-ring)
When it's not any of the above
When to call a plumber

A dripping tap is usually a small, cheap fix rather than a sign anything serious is wrong, but left alone it wastes a surprising amount of water and can eventually stain your sink or bath with limescale. This guide covers diagnosing which type of tap you've got and the quick version of both fixes; if you already know you've got a traditional washer tap, our full guide on replacing a tap washer goes into more detail on tools, sizing and dealing with a seized headgear.

Almost every dripping tap comes down to one of two mechanisms wearing out, a rubber washer or a ceramic disc cartridge, and knowing which one you've got before you start saves you buying the wrong part or taking apart the wrong thing. It's usually obvious once you know what to look for.

Why taps drip

Almost every drip comes down to a worn seal somewhere inside the tap. In older, traditional taps, this is usually a rubber or fibre washer that's hardened or perished with age.

In newer taps with a single lever handle, it's more often a ceramic disc cartridge that's picked up limescale or a tiny bit of grit, stopping it from sealing perfectly. Either way, the fix is the same principle: replace the worn part.

Tools you'll need

Adjustable spanner
Flathead and crosshead screwdrivers
A replacement washer or cartridge that matches your tap (take the old one to a plumbers' merchant if you're not sure)
A cloth to protect the tap finish from spanner marks

An adjustable spanner worth a look

Stanley 8in Adjustable Wrench

£9.14 (correct as of August 2026)

An 8-inch adjustable wrench from Stanley with a chrome vanadium forged body and a knurled screw for one-handed jaw adjustment.

We like

Chrome vanadium steel body with a phosphate and polished chrome finish, more corrosion resistant than a basic steel wrench
Knurled adjustment screw makes it easy to fine-tune the jaw width with one hand
Marked with both metric and imperial (SAE) scales, useful if you're not sure which your tap's fittings are sized in

Worth checking

Fixed 8-inch length, so it won't reach into the tight, awkward gaps under a sink the way a basin wrench can

Jaw capacity: 8 inches (200mm)
Length: 200mm
Material: Chrome vanadium (alloy) steel
Finish: Phosphate coated, polished chrome
Weight: 0.3kg
Measurement markings: Metric and imperial (SAE)

Specifications above listed by Amazon and may change. Check the current listing before buying. If we've got something wrong, let us know and we'll fix it.

View on Amazon

First, work out which type of tap you have

If your tap has separate hot and cold handles that you turn, and it's an older style, it likely uses a traditional washer. A single lever that moves smoothly with barely any resistance and controls both flow and temperature almost certainly means a ceramic disc cartridge inside instead. This matters because the two fixes are different.

Fixing a traditional washer tap

The short version: isolate the water and let the tap drain, remove the handle, unscrew the headgear the handle sits on, and swap the washer at its base for an exact size match, then reassemble and test.

The part that actually trips people up is a seized headgear rather than the washer itself. Our full guide on replacing a tap washer covers the right tools, getting the washer size right, and freeing a stuck headgear without damaging the tap.

Fixing a ceramic disc tap

Ceramic disc cartridges rarely wear out in the way washers do, but they can develop a drip if limescale or debris gets between the discs, stopping them sealing fully. If you're not sure whether you're actually dealing with one, our guide on what a ceramic disc tap is explains how the mechanism works and how to spot it.

The short version: isolate the water, remove the handle, lift out the cartridge, then clean it gently if the drip is minor or replace it whole if cleaning doesn't help, since cartridges are precision made and not really designed to be repaired once worn. Cartridges are specific to the tap's brand and model, so our full guide on replacing a tap cartridge covers sourcing the exact match and the full step-by-step swap.

Fixing a leaking spout (O-ring)

A leak from around the base of the spout, particularly when you swivel it, is a different problem to a drip from the outlet, and it's almost always down to a worn O-ring rather than the washer or cartridge above. Water appearing there, especially only when the spout is turned from side to side, points squarely at the O-ring.

Turn off the isolation valves for that tap, or the main stopcock if none are fitted, then open the tap to release pressure.
Some taps need the handle and cartridge removed first to free the spout; others allow the spout to simply lift or twist off the tap body. Check whether yours is held by a small grub screw at the base before pulling.
Lift the spout straight up and off the tap body, working it gently side to side if it's stiff rather than forcing it.
You'll usually find one or two O-rings seated in grooves around the base of the spout's spigot. Roll the old ones off, noting how many there are and their thickness, then clean the groove of any old grease or debris.
Lightly grease the new O-ring with food-safe silicone grease, seat it in the groove, and push the spout back onto the tap body.
Reassemble anything else you removed, turn the water back on, and check the base for leaks with the spout both stationary and turned.

Take the old O-ring with you when buying a replacement rather than guessing the size, since O-rings are sold by internal diameter and thickness and even a slightly wrong size won't seal properly.

When it's not any of the above

A drip that persists straight after a full washer, cartridge or O-ring replacement can occasionally point to limescale build up further inside the tap body itself, which sometimes needs a full descale rather than another part swap.

When to call a plumber

If the drip is coming from a joint rather than the tap mechanism itself, if you can't locate or safely operate your isolation valve, or if the tap is old enough that replacement parts are no longer available, it may be more sensible to replace the tap entirely rather than keep patching it. See our guide on how to install a tap yourself if you decide to go that route, browse our top 10 kitchen taps for a shortlist of replacements, or search WaterSafe for an approved plumber near you.

A dripping outdoor tap is also worth sorting before winter sets in. Our top 10 outdoor taps page covers frost-proof options if yours needs replacing rather than repairing.

Frequently Asked Questions

: An intermittent drip, rather than a constant one, often points to a partially worn washer or cartridge that's still mostly sealing correctly, or to slight changes in water pressure affecting how well a borderline seal holds. It's usually still worth fixing, since intermittent drips tend to become constant ones over time as the part wears further.
: Feel is the quickest test: a handle that takes a full turn to open almost always means a washer, while a lever with hardly any resistance to it almost always means a ceramic disc cartridge. Our guides on replacing a tap washer and what a ceramic disc tap is go into each mechanism in full.
: It's worth fixing sooner rather than later. A slow drip can waste several litres of water a day, which adds up on a water meter, and dripping water often leaves limescale or rust staining on the sink or bath below over time. The fix itself is usually inexpensive, so there's little reason to put up with it long term.
: Check the tap manufacturer's website first, as most keep spare parts available for years after a model is discontinued. A plumbers' merchant may also be able to suggest a compatible universal alternative if the exact cartridge is no longer available. Failing that, it's usually more practical to replace the whole tap.
: No, not safely. Any tap repair that involves removing the handle or headgear requires the water supply to that tap to be isolated first, otherwise you'll be dealing with a constant flow of water the moment anything is loosened. Always isolate the supply and release pressure by opening the tap before starting any repair.
: There's no single universal size, since it depends on your tap's spout spigot diameter. The most reliable approach is to take the old O-ring to a plumbers' merchant to match it in person, or buy a multi-size O-ring kit that covers the common sizes used in domestic taps.
: It's better to use a proper food-safe silicone grease if you can get hold of one. Petroleum-based products like Vaseline can degrade rubber O-rings over time, which shortens the life of the very part you've just replaced.
: This is the classic sign of a worn O-ring, since the seal is under the most stress exactly when the spout is moving. A spout that leaks constantly regardless of position more often points to a seal at the tap's base instead, which is more a case for reseating the tap properly, covered in our guide on installing a tap yourself.