Dripping Tap? Causes, How to Fix It, and What It Costs

A dripping tap is one of those household annoyances that is easy to ignore and surprisingly expensive to leave alone. It starts as the odd drip you only notice at night, then becomes a steady tick against the sink that you stop hearing entirely. The good news is that a dripping tap almost never means the whole tap has failed. In the vast majority of cases the culprit is a single small part inside the tap that has worn out and needs replacing. That is a job many people can do themselves in under an hour, and it is a cheap repair even when a plumber does it.

This guide covers why taps drip in the first place, how to work out which type of tap you have, a step-by-step DIY fix, when the sensible move is to stop and call someone, how much water and money a drip actually wastes over a year, and what the repair typically costs in London and across the UK.

Why taps drip in the first place

Every tap works by pressing one surface against another to hold back pressurised water. When you turn the tap off, a moving part is pushed down onto a fixed seat, and the seal between them is what stops the flow. A drip happens when that seal is no longer perfect. Water is under constant pressure in your pipes, so even a tiny imperfection in the seal lets a thread of water escape, and that is your drip.

The reason the seal fails comes down to a handful of common faults. Knowing which one you are dealing with makes the repair straightforward, because each fault has a specific, inexpensive fix.

A worn rubber washer

Traditional taps, the sort with two separate handles that you turn several times to open and close, rely on a small rubber or fibre washer at the bottom of a spindle. Every time you turn the tap off, that washer is compressed against a metal seat. Over years of use the rubber hardens, cracks, or wears thin, and it can no longer form a tight seal. A worn washer is the classic cause of a dripping tap and by far the most common on older British taps. Replacing it costs pennies.

A worn ceramic disc cartridge

Most taps made in the last twenty years or so, especially quarter-turn taps and single-lever mixers, use ceramic discs instead of a rubber washer. Two polished ceramic discs slide across each other, and when their holes line up water flows, when they are offset it stops. Ceramic lasts far longer than rubber, but grit in the water supply can scratch the discs, limescale can build up on them, and eventually they wear. When a ceramic cartridge fails you usually replace the whole cartridge rather than a single washer.

A damaged valve seat

The valve seat is the fixed metal ring that the washer presses against. Over time, water and grit passing over it can erode or corrode the seat so that it is pitted and no longer smooth. When this happens, a brand new washer will still drip because it cannot seal against a rough surface. This is a frequent reason a tap keeps dripping even after someone has changed the washer. The seat can often be reground with an inexpensive tool, or a seating insert can be fitted.

A perished O-ring

O-rings are the rubber seals that stop water escaping around the moving parts of a tap, most noticeably around the spout of a mixer tap. A perished O-ring tends to cause a leak from the base of the spout or around the handle rather than a drip from the nozzle, but it is part of the same family of faults and is cheap to replace.

A worn cartridge in a mixer or monobloc tap

Kitchen mixer taps and monobloc bathroom taps, where a single body carries both hot and cold through one spout, use cartridges internally. A monobloc tap is a single tap that sits in one hole and mixes hot and cold. When one of these cartridges wears, the tap may drip from the spout, become stiff, or fail to shut off fully. The fix is a replacement cartridge matched to that tap.

How to identify your tap type

Before you can fix a drip you need to know what you are working with, because the internals differ. You can usually tell your tap type just by using it.

1. Traditional pillar taps. Separate hot and cold taps, each turned several full rotations to open. These almost always contain a rubber washer and a valve seat. Common on older sinks and basins.
2. Quarter-turn taps. Look similar to pillar taps but open fully with a quick quarter or half turn of the handle. These use ceramic disc cartridges.
3. Single-lever mixer taps. One spout with a single lever you push up or down for flow and side to side for temperature. Common in modern kitchens. These use a single mixing cartridge.
4. Monobloc mixer taps. One spout fed from a single body, often with two small quarter-turn handles either side, sitting in one hole in the basin. These use two ceramic cartridges, one per side.

The other thing worth noting is where the drip is coming from. A drip from the spout nozzle points to a worn washer, cartridge, or valve seat. Water escaping from around the base of the handle or the bottom of the spout points to a gland nut or O-ring. This tells you which part to buy before you start.

Step-by-step: fixing a dripping tap yourself

A washer or cartridge change is well within reach for anyone comfortable with a spanner and a screwdriver. The single most important step, and the one people skip at their peril, is isolating the water before you open the tap. Skipping it turns a small repair into a soaked kitchen.

What you will need

• An adjustable spanner and a set of screwdrivers, flat and cross-head
• A replacement washer or cartridge to match your tap
• An old towel and a bowl or plug for the plughole
• Penetrating oil in case fittings are stiff, and a soft cloth

The method

1. Isolate the water supply. Look under the sink for a small isolation valve on the pipe feeding the tap. A slotted screw across the flow means open; turn it a quarter turn with a flat screwdriver so the slot sits across the pipe to shut it off. If there is no isolation valve, turn off your main stop tap. Our guide on how to turn off your water stop tap in London walks through exactly where to find it.
2. Open the tap and drain it. Turn the tap on to release any water left in the pipe and to confirm the supply really is off. It should run to a trickle and stop. Put the plug in or cover the plughole so nothing small disappears down the drain.
3. Prise off the handle cover. Most taps hide the retaining screw under a small cap, often marked hot or cold, on top of the handle. Gently lever it off with a flat screwdriver, then undo the screw beneath and lift the handle away.
4. Remove the headgear or cartridge. Underneath you will find a hexagonal nut, the headgear nut, holding the working part in place. Steady the tap body and undo the nut with your spanner. Lift out the spindle assembly on a traditional tap, or the ceramic cartridge on a modern one.
5. Replace the worn part. On a traditional tap the washer sits at the very bottom of the spindle, held by a small nut or simply pushed on. Fit a matching replacement. On a ceramic tap, take the old cartridge to a merchant and buy a like-for-like replacement, as sizes vary between makes. While you are in there, check the valve seat is smooth; if it feels pitted, that is likely why it kept dripping.
6. Reassemble in reverse. Refit the headgear or cartridge, tighten the nut firmly but without forcing it, replace the handle and screw, and press the cap back on.
7. Turn the water back on and test. Reopen the isolation valve or stop tap slowly, then run the tap and turn it off. Watch for a minute. No drip means the job is done. Turning the supply back on gently avoids a pressure surge through the system.

If you have swapped the washer and the tap still drips, the valve seat is almost certainly worn. That needs a reseating tool to grind it flat again, or a seating washer to bridge the damage. It is a cheap part but a slightly fiddlier job, and it is a common point at which people decide to call a plumber.

What forums like r/DIYUK and DIYnot generally say

Browse the long-running plumbing threads on communities such as r/DIYUK and DIYnot and a broad consensus emerges, and it is worth taking seriously because it reflects a lot of hard-won experience rather than marketing.

The first recurring theme is that a washer or cartridge swap is genuinely a beginner-friendly job, and most people who attempt it are glad they did. The second, and more sobering, theme is that older taps frequently fight back. Seized headgear nuts, corroded fittings, and taps that have not been touched in decades can turn a ten-minute job into an afternoon, and occasionally the tap or the pipework beneath it is damaged in the process. Experienced posters repeatedly warn newcomers to know where their stop tap is before they start and to accept that on a very old tap, replacing the whole tap can end up easier than saving it.

The third common point is about ceramic cartridges: because there is no single standard, matching the exact replacement is often the hardest part of the whole job, and people advise taking the old one to the merchant rather than guessing. None of this is meant to put you off. It is simply the honest picture: the repair is easy when it goes well, and the risk is not the washer itself but the age and condition of everything around it.

When it is not worth doing yourself

DIY makes sense when the tap is reasonably modern, the fittings move freely, and you can isolate the water with confidence. There are clear situations where calling a plumber is the better call, and recognising them early saves money rather than costing it.

• The isolation valve or stop tap will not move or does not fully stop the flow. Without a reliable way to shut the water off, any attempt to open the tap risks flooding. This is a job for someone who can fit a new isolation valve first.
• The headgear nut or fittings are seized solid. Applying more and more force to a corroded fitting is how pipes get twisted and joints get cracked. If penetrating oil and reasonable effort do not free it, stop.
• You have changed the washer and it still drips. That points to a worn valve seat, and if you are not equipped to reseat it, a plumber will have it sorted quickly.
• The tap is leaking from the body or the pipework below, not just dripping from the spout. That can be a sign of a more significant fault, and standing water under a sink can cause damage of its own. If you are dealing with an active leak rather than a slow drip, our water leak repair in London page explains how we handle it.
• It is late, water is escaping faster than you can manage, or you simply do not have the tools. There is no shame in this. A dripping tap that has become a running tap overnight is exactly the sort of thing our emergency plumber in London service exists for.

The water and money a drip quietly wastes

It is tempting to think a single drip cannot matter much. The reality is different because a drip never stops. It continues every second of every day, and small volumes add up relentlessly over weeks and months. Water industry guidance in the UK has long pointed out that a steadily dripping tap can waste a meaningful amount of water over the course of a year, enough to be worth fixing on both environmental and financial grounds.

The cost angle depends on whether you are on a water meter. If you are, every litre that drips away is a litre you pay for, on both the supply and the wastewater side of the bill, so a persistent drip shows up as real money over a year. If you are on unmetered rates you are not billed by volume, but the waste is still real, and a hot tap that drips is also wasting the energy used to heat that water, which lands on your gas or electricity bill instead. Rather than lean on a specific figure that varies by tap, pressure, and tariff, the honest summary is this: a drip is cheap to fix and steadily expensive to ignore, and a dripping hot tap costs more than a dripping cold one because you are paying to heat water that goes straight down the plughole.

What a tap repair typically costs

The figures below are typical UK trade cost-guide ranges rather than fixed quotes. What you actually pay depends on your area, the tap, how accessible it is, and whether parts such as cartridges are readily available. London labour rates sit at the higher end of national ranges.

• Parts alone. A rubber washer costs very little, often under a pound or two. A ceramic cartridge is more, commonly in the region of a few pounds to around twenty depending on the tap. These are the DIY costs.
• A plumber replacing a washer or cartridge. As a straightforward job, this typically falls within a plumber's minimum call-out or first-hour charge, which across the UK commonly runs from around sixty to over a hundred pounds, with London at the upper end. The work itself is usually quick once someone is on site.
• Reseating a worn valve seat. A little more involved than a washer change but still usually within an hour of labour plus a low-cost part.
• Replacing the whole tap. If the tap is old, seized, or not worth saving, fitting a new one is often the pragmatic choice. Expect labour of roughly one to two hours plus the price of the new tap, which varies enormously by style and quality.

The reason a simple drip can feel disproportionately expensive to have fixed is the call-out and minimum-charge structure, not the difficulty of the work. That is exactly why a confident DIY washer change is such good value, and why, if you are calling someone out anyway, it is worth asking them to check any other dripping taps in the house while they are there.

How we handle it

We keep our approach to tap repairs deliberately straightforward. We give you an honest arrival window rather than a vague promise, and we agree the price with you before we travel, so there are no surprises when we knock on the door. A dripping tap is a small job for us, and we would always rather tell you plainly whether it is a quick washer change or a case for a new tap than pad out the work. If your drip has turned into something more urgent, our emergency plumber in London team can help, and if water is escaping rather than merely dripping, start with our water leak repair page.

Whether you fix it yourself or call us, the message is the same: a dripping tap is worth dealing with sooner rather than later. It is cheap to put right, it wastes water and money every day you leave it, and the small part inside that is causing it will only get worse.