How to Fix a Leaking Tap

A tap drips because the seal that stops water flowing when it's closed has worn out — that's either a rubber washer pressed against a valve seat, or a ceramic disc cartridge, depending on the tap. Constant use, mineral deposits from London's hard water, and simple age all wear down that seal until it can't hold back the mains pressure any more, so water forces its way past and drips from the spout.

A dripping mixer tap almost always means a worn ceramic cartridge rather than a washer — mixer taps stopped using traditional washers decades ago in favour of the disc mechanism, which is why the fix is slightly different from a classic pillar tap.

You can tell which type you have by how the tap feels to turn: a traditional washer tap turns through several full rotations before it shuts off, while a ceramic cartridge tap — including almost every mixer tap — shuts off within a quarter turn or less.

• Washer tap: separate hot and cold taps, several turns to open/close, common on older bathroom and kitchen suites across London's period housing stock.
• Ceramic cartridge tap: a single lever or quarter-turn handles, fitted to almost all mixer taps and most taps sold in the last 15-20 years.

Once the handle is off, you'll see the difference immediately — a washer tap shows a spindle with a rubber disc on the end, while a cartridge tap shows a sealed plastic or brass cylinder with no visible rubber part.

Fixing a leaking tap takes five steps: isolate the water, remove the handle, undo the headgear, swap the worn part, then reassemble and test. Work through each one in order and don't skip the isolation step, even for a quick job.

1. Turn off the water supply. Shut the isolation valve directly under the tap if one's fitted, or the main stopcock if not, then open the tap to let any remaining water drain out.
2. Remove the handle. Prise off the small hot or cold indicator cap on top, undo the screw underneath with a flathead screwdriver or Allen key, and lift the handle straight off the spindle.
3. Undo the headgear. Grip the tap body with one spanner if needed and use an adjustable spanner or basin wrench to unscrew the headgear nut, then lift the whole valve assembly out.
4. Replace the washer or cartridge. On a traditional tap, pop the old rubber washer off the end of the spindle and press on a same-size replacement; on a mixer or modern tap, lift out the entire ceramic cartridge and fit an exact matching replacement — take the old one to the shop to match it.
5. Reassemble and test. Wrap PTFE tape clockwise round any exposed thread, screw the headgear back in, refit the handle, turn the water supply back on gradually, and run the tap to confirm the drip has stopped.

Stopping a dripping mixer tap means replacing the ceramic disc cartridge, not a washer — the cartridge sits directly under the single lever or handle and controls both temperature and flow in one part. Because mixer cartridges are brand and model specific, the most reliable way to get the right replacement is to remove the old one first and take it with you, or match it against the tap manufacturer's part number if it's printed on the body.

If the cartridge is seized in place from mineral scale, which is common with London's hard water, a firm turn with a cartridge-puller tool or a few taps with a soft mallet usually frees it without damaging the tap body.

Call a plumber if the tap keeps dripping after you've replaced the washer or cartridge, if the handle or headgear won't budge without excessive force, or if you notice damaged threads, a cracked tap body, or water leaking from the base rather than the spout. Those signs usually mean a worn valve seat or a tap that's reached the end of its life rather than a simple part swap.

RenoPlumb's tap repair service covers kitchen, bathroom, and mixer taps across London, including Tower Hamlets, Hackney, Islington, Newham, and Southwark, with every job carried out by a Gas Safe registered plumbing team based on Commercial Road in E1. Call 07460 824073 if you'd rather have it sorted than take the handle apart yourself.

It depends entirely on what's worn — a simple washer swap is quick work, while a seized mixer cartridge or a damaged valve seat takes longer, so we never quote a figure without seeing the tap first. Every RenoPlumb job starts with a free, no-obligation quote, so asking us to look costs nothing either way. For more detail on how jobs are priced, see our pricing page.

RenoPlumb fixes leaking and dripping taps across East and Central London from our base on Commercial Road, E1 — covering Tower Hamlets, Hackney, Islington, Newham, Southwark, Canary Wharf, Shoreditch, Whitechapel, Bethnal Green, and Mile End. If you're in Tower Hamlets or nearby and would rather book a plumber than take the tap apart yourself, our tap repair team can usually get to you the same day.