Dripping Taps: Why They Drip and How They Are Properly Fixed
A dripping tap is the most ignored plumbing fault in most homes and one of the easiest to put right.
A dripping tap is the most ignored plumbing fault in most homes and one of the easiest to put right. The drip is almost always a worn washer on a traditional tap or a failed ceramic cartridge on a quarter-turn or mixer tap, and both are small parts. Left alone, the constant flow marks the sink or bath, wastes water you are metered for, and can wear the seat inside the tap body so that the eventual repair is bigger than it needed to be.
Two kinds of tap, two different repairs
Traditional taps that turn several times use a rubber washer that seals against a brass seat. Wear the washer and the tap drips. Quarter-turn and most modern mixer taps use ceramic discs in a cartridge, which do not wear in the same way but can be damaged by grit or limescale, and are replaced as a complete cartridge rather than rebuilt. Identifying which type you have decides what part you need and whether the repair takes ten minutes or requires a specific manufacturer's cartridge.
Where the drip is coming from matters
Water from the spout when the tap is closed is the washer or cartridge. Water weeping from around the handle or base when the tap is open is the O-ring or gland packing, a different and usually simpler fix. Water from underneath the sink at the tap tails is the connection, not the tap mechanism at all — often a flexible tap connector that has aged. Looking properly before dismantling anything saves buying the wrong parts.
Isolating the water safely
Most taps installed in the last couple of decades have small isolation valves on the supply tails under the basin or sink, turned with a screwdriver. Where there is none, the stopcock isolates the cold and, on a gravity system, the hot needs the cylinder or tank isolating too. Always open the tap after isolating to release residual pressure and confirm the water is genuinely off before undoing anything.
The repair itself
For a washer tap: remove the handle, unscrew the headgear, replace the washer, and inspect the seat for scoring or pitting. A damaged seat needs re-cutting or the tap will drip again within weeks with a brand new washer in it, which is exactly why some 'fixed' taps start dripping again so soon. For a ceramic tap: match the cartridge to the make, model and hand — cartridges are often handed and are not interchangeable between brands.
When replacing the tap is the better answer
If the body is heavily corroded, the seat is badly pitted, the cartridge is obsolete, or the tap is a low-cost unit where parts cost close to a new one, replacement is more sensible than repair. It is also the moment to check the tap suits your system: some mixers need balanced pressures and perform poorly with a high-pressure cold and a gravity-fed hot, which is a design mismatch no repair will resolve.
Preventing the next one
Do not over-tighten taps to stop a drip — that is what destroys the seat and turns a washer job into a re-cutting job. Descale spouts and aerators periodically in hard water areas. Replace ageing flexible connectors when you have the tap apart anyway, since they are cheap and are a common source of under-sink leaks later on.
Book a tap repair or replacement
Tell us the tap type and where the water is coming from, and we will arrive with the right washers or cartridge.
Questions we get asked
Why did my tap start dripping again after a new washer?
Almost always a worn or pitted seat. The new washer cannot seal against a damaged surface, so the seat needs re-cutting or the tap replacing.
Are ceramic cartridges interchangeable between brands?
No. They vary in size, spline and handing, so the cartridge has to match the specific tap make and model.
Is a dripping tap actually worth worrying about?
On a water meter, yes. It also stains sanitaryware and slowly damages the seat, making the eventual repair larger.
Why does my mixer tap run hot then cold?
Often unbalanced pressures between a mains cold and a gravity hot supply. That is a system design issue rather than a fault in the tap.
Can I fix a tap without turning the mains off?
If there is an isolation valve on the tail, yes. Without one, the mains or the cylinder has to be isolated first.