How to Fix a Dripping Tap: A Step-by-Step Guide
Stop a dripping tap in the UK: identify your tap type, replace the washer or cartridge, avoid common mistakes and know when to call a plumber.
A dripping tap is more than an irritation. One drop a second adds up to a surprising amount of wasted water over a month, and the constant drip can stain basins and wear fittings. The good news is that most drips are one of two simple faults, and many people can fix them with basic tools in under an hour.
First, work out what type of tap you have
The repair depends on the mechanism inside.
- Traditional pillar taps with a separate hot and cold tap that you turn many times usually use a rubber washer.
- Quarter-turn taps that go from off to on in a short turn use a ceramic disc cartridge.
- Mixer taps with a single lever use a cartridge, and can be more fiddly.
- Monobloc kitchen taps are similar to mixers and often use a cartridge.
If a tap drips from the spout when it is off, the washer or cartridge is probably worn. If it leaks around the base or handle, it is more likely a worn O-ring or seal.
Tools and bits you will need
- Adjustable spanner
- Screwdrivers, flat and cross-head
- A small towel or cloth
- Replacement washer, cartridge or O-ring (take the old part with you to the shop to match it)
- Plumber's grease
Step by step: replacing a washer
- Turn the water off. Use the small isolating valve on the pipe beneath the tap if there is one. If not, shut off the stopcock and run the tap to drain it. See finding your stopcock if unsure.
- Block the plug hole. A cloth stops small screws vanishing.
- Remove the cover. Prise off the cap on the top, then undo the screw underneath to lift the handle.
- Undo the headgear nut. Use the spanner, holding the tap body steady so you do not twist the pipe.
- Lift out the headgear. At the bottom you will find the washer, either pressed on or held with a small nut.
- Replace the washer. Fit the new one the same way up as the old.
- Reassemble. Smear a little grease on the threads, tighten gently and refit the handle.
- Turn the water on and test. Check there is no drip and no leak around the joints.
Step by step: replacing a ceramic cartridge
- Isolate the water and drain the tap as above.
- Remove the handle and any shroud.
- Unscrew the cartridge using a spanner.
- Match the old cartridge to a new one exactly, as there are different sizes and spline counts.
- Fit the new cartridge, reassemble and test.
Common mistakes
- Over-tightening. Cracking a basin or damaging the seat is easy. Tighten until firm, not hard.
- Not matching parts. A near fit will leak. Take the old part with you.
- Forgetting to isolate the water. It will make a mess.
- Ignoring a worn seat. If a new washer still drips, the valve seat may be pitted. A plumber can fit a reseating tool or replace the tap.
When to leave it to a plumber
Call a plumber if:
- the tap is seized or corroded and will not come apart;
- the pipes move or leak when you try to undo a fitting;
- there is no isolating valve and you cannot shut the water off;
- the tap is old, damaged or the finish is flaking, in which case you may want a new tap.
For what a repair is likely to cost, see the cost to replace a tap.
How much a drip really costs
A tap that drips once a second can waste a surprising amount of water over a year. On a water meter, and especially on a hot tap where you are also paying to heat the water, that adds up to a noticeable sum. It is also why a drip is worth fixing even when it seems minor. The exact figure depends on the size of the drip, so treat any number you read as a rough guide.
Worked example: a hot tap in a rented flat
A tenant notices the bathroom basin hot tap drips overnight. It is an old quarter-turn tap with a ceramic cartridge. They turn off the small isolation valve below the basin, remove the cap and handle, and find a cartridge with a hairline scratch. A matching replacement from a plumbers' merchant takes about thirty minutes to fit. Because it is a rental, they would normally report it to the landlord or agent first, as explained in plumbing in a rental, unless the agreement says tenants handle minor repairs.
Match the symptom to the part
| Symptom | Most likely cause |
|---|---|
| Drips from the spout only when off | Washer or cartridge |
| Drips from the base of the spout on a mixer | Worn spout O-ring |
| Water around the handle | Gland packing or handle seal |
| Whistling or juddering when turned | Worn washer or loose jumper |
| Drips from the spout despite a new washer | Pitted valve seat |
Hard water, old taps and awkward fittings
- In hard-water areas limescale locks the headgear in place. Soak it in a descaling solution before forcing anything.
- Some old taps use a nylon jumper rather than a plain washer. Check the old part before shopping.
- Taps with a plastic shroud may need a gentle twist, not a pry, to avoid cracking.
- If the basin is cracked or the tap is loose in the hole, replacement is the better route; see the cost to replace a tap.
Final check
After refitting, leave a dry tissue under the spout overnight. A single damp patch tells you the drip is not fixed, while a dry tissue the next morning confirms the repair.
Frequently asked questions
Why does my tap still drip after changing the washer?
The valve seat, where the washer sits, may be worn or pitted. It can be refaced with the right tool, or the tap replaced.
Is a dripping hot tap different from a cold tap?
The repair is the same, but a dripping hot tap wastes heated water, so it costs you more than a cold drip.
Can I fix a dripping tap without turning off the water?
No. Isolate the supply first, or you risk water spraying out when you remove the headgear.