How do I fix a dripping tap?
How to stop a tap dripping by replacing the washer or ceramic cartridge, including how to tell which type of tap you have.
- Difficulty
- beginner
- Time
- 45 min
- Read
- 4 min
- Safety
- caution
Short answer
Turn off the water, open the tap to drain it, then take the tap apart and replace the perished rubber washer (traditional taps) or the ceramic disc cartridge (quarter-turn taps). The part costs a few pounds; the job takes about 45 minutes the first time.
Do this first
A dripping tap wastes a surprising amount of water — a drip a second is thousands of litres a year — and the fix is nearly always a single cheap part. The only real decision is which type of tap you have. If the handle turns several rotations, it's a traditional compression tap with a rubber washer. If it stops after a quarter or half turn, it's a ceramic disc tap with a cartridge.
Safety
What you'll need
- Adjustable spanner
- Flat and cross-head screwdrivers
- Replacement washer or ceramic cartridge
- Cloth to protect the tap finish
- Penetrating oil for seized fittings (optional)
Step by step
- Turn off the water at the isolation valve under the basin, or at the main stopcock.Isolation valves have a slot for a flat screwdriver — a quarter turn so the slot sits across the pipe means off.
- Open the tap fully and let it drain, then plug the basin.Plugging the basin stops small screws disappearing down the waste, which is the classic way this job goes wrong.
- Remove the tap head — usually a screw under the hot/cold indicator cap, or a grub screw at the side.The cap normally levers off with a small flat screwdriver. Go gently; they crack.
- Unscrew the valve body with an adjustable spanner, wrapping a cloth around it first.The cloth stops the spanner jaws chewing the chrome.
- Identify what you've got: a rubber washer on the bottom of a brass spindle, or a sealed ceramic cartridge.Take the old part to the shop rather than guessing sizes — 'half inch' taps use several different washer diameters.
- Fit the replacement, seating the washer squarely or the cartridge on its locating lug.A washer at an angle will drip immediately. The cartridge only goes in one way round.
- Reassemble, tighten the valve body firmly but not brutally, and refit the handle.Overtightening cracks the ceramic seat inside the tap body — hand tight plus a quarter turn is enough.
- Turn the water back on slowly and check for leaks at the base and around the spindle.Slowly, so a mistake shows as a trickle rather than a jet.
Tips
- Photograph each stage as you dismantle. Reassembly is much easier with a reference, and washers and spacers go back in a specific order.
- If the tap drips from the spout, it's the washer or cartridge. If it weeps from under the handle, it's the O-ring on the spindle — a different, equally cheap part.
- If the valve body is seized solid, penetrating oil and 20 minutes of patience beats more force. Excess force twists the tap body and turns a £3 job into a new tap.
- Replacing both taps at once, even if only one drips, saves doing the whole job again in six months.
Common mistakes
- Not checking the water is really off — The isolation valve may be seized open. Always test by opening the tap.
- Overtightening on reassembly — Cracks the seat in the tap body — after which no washer will seal and the whole tap needs replacing.
- Guessing the washer size — Take the old one with you. There are several standard sizes and they are not interchangeable.
- Not plugging the basin — The screw will go down the waste. It always does.
If it doesn't work
Still drips after a new washer
Cause: The brass seat the washer presses against is pitted or scored — Fix: Use a tap reseating tool, or fit a washer-and-seat set that includes a plastic seat insert.
Water weeps from around the handle
Cause: Perished O-ring on the spindle, not the washer — Fix: Replace the O-ring — it's the small rubber ring around the spindle shaft.
Tap now stiff to turn
Cause: Overtightened valve body, or missing lubrication — Fix: Slacken slightly and apply a smear of silicone grease to the spindle threads.
Questions people ask
How do I know if my tap has a washer or a cartridge?
Turn the handle. Several full rotations from off to fully on means a traditional compression tap with a washer. A quarter or half turn means a ceramic disc cartridge.
Can I fix a mixer tap the same way?
A two-handle mixer, yes — each side is an independent valve. A single-lever mixer uses a different cartridge, usually held by a grub screw under the lever, and the cartridge is replaced as one unit.
Is it worth just buying a new tap?
If the tap is old, corroded or you dislike it anyway, yes — new taps start cheap. But a washer costs under a pound and will usually give you several more years.