How to fix a dripping tap

How to fix a dripping tap

A dripping tap wastes water, stains the basin and keeps you awake. The fix is usually a worn washer or a tired ceramic cartridge, and both are cheap parts you can change yourself.

The main skill is knowing which kind of tap you have, and turning the water off properly before you start.

Guide · The Honest Fix

Why taps drip

Which kind of tap do you have?

• Compression (washer) tap: the handle turns several times from fully open to fully closed, and gets gradually stiffer as it shuts. Inside, a rubber washer presses down onto a seat. When the washer wears or hardens, water gets past it.
• Ceramic disc tap: the handle turns only a quarter or half turn and stops firmly. Inside, a cartridge holds two ceramic discs that slide over each other. Scale, grit or wear on the discs stops them sealing.
• Mixer and monobloc taps: most modern ones use ceramic cartridges. Two-handle mixers have a cartridge on each side, so work out whether the drip is warm or cold and change only that one. Single-lever mixers usually have one cartridge that does both.

Where is it dripping from?

• From the spout: the washer or cartridge isn’t sealing. That’s what this guide fixes.
• Around the handle: on an older tap, the gland packing or O-ring around the spindle is worn. On a cartridge tap, it’s usually the cartridge’s own O-rings.
• At the base of a swivel spout: the O-rings under the spout have worn. Replacing them is a similar job.

Before you start

1. Turn off the water to the tap. Look for an isolation valve on the pipe under the basin or sink. Turn the slot a quarter turn with a flat screwdriver, so it sits across the pipe. If there isn’t one, turn off the stopcock (often under the kitchen sink).
2. Drain the tap by opening it fully until the flow stops.
3. Put the plug in so small parts can’t go down the plughole.
4. Lay a towel in the basin to catch dropped parts and protect the surface.
5. Photograph each step as you take the tap apart, so you know how it goes back together.

Step by step: washer (compression) tap

1. Prise off the cap on top of the handle with a small flat screwdriver, and undo the screw underneath.
2. Pull off the handle. On older taps you may also need to unscrew a metal shroud to get to the headgear.
3. Undo the headgear nut with the spanner, with the cloth round it. Hold the tap body steady with your other hand so it doesn’t twist on the basin.
4. Replace the washer on the end of the headgear. It’s either held by a small nut or pushed onto a stub. Most basin and kitchen sink taps take a 1/2-inch washer, and bath taps usually take a 3/4-inch one. Take the old washer with you to match it.
5. Replace the O-ring on the spindle while it’s apart, if it looks worn or flattened.
6. Clean off any scale on the headgear and the seat inside the tap body.
7. Reassemble in reverse order. Nip the headgear up firmly, but don’t force it.
8. Turn the water back on slowly at the isolation valve, then open and close the tap a few times and check for drips and leaks.

Step by step: ceramic cartridge tap

1. Remove the cap and handle as above. On a lever mixer, there’s often a small grub screw under or behind the lever instead.
2. Unscrew the cartridge with the spanner, holding the tap body steady. Note which way it sat.
3. Check the cartridge. Sometimes cleaning off scale and grit and replacing the O-rings is enough. If the discs are chipped or scored, replace the cartridge.
4. Fit the new cartridge, making sure it matches the old one and turns the same way to close. Tighten it firmly, but don’t overdo it.
5. Refit the handle so it lines up correctly in the off position.
6. Turn the water back on slowly, fully open the isolation valve, and check for drips at the spout and leaks around the handle.

If it still drips

On a washer tap, the seat that the washer presses against may be worn or pitted, so even a new washer can’t seal. You can buy a reseating tool or a seat repair kit from a plumbers’ merchant to fix this.

On a cartridge tap, check that you have the right cartridge and that it’s fully tightened. If the tap is old, corroded or a cheap unbranded one with no spare parts available, replacing the whole tap is often the better option.

DIY or Hire?

DIY. Changing a washer, O-ring or cartridge is one of the most achievable plumbing jobs in the house, and the parts cost very little.

Call a plumber if the water won’t turn off properly, the tap fights back, or the drip is on a thermostatic shower or bath mixer. Those have more complicated internals and safety parts.

Common mistakes

• Overtightening the headgear or cartridge, which can crack it or damage the new washer.
• Not holding the tap body, so it twists and loosens on the basin or strains the pipes.
• Fitting the wrong cartridge, so the tap won’t shut off or turns the wrong way.
• Leaving the isolation valve part-closed afterwards, which leaves the tap with poor flow.
• Dropping small parts down the plughole.

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