Fix It Britain

A mixer tap that drips from the spout, leaks around the lever or leaves a puddle round its base is annoying, but it rarely means buying a new tap. Most mixer taps in UK kitchens and bathrooms use replaceable ceramic cartridges and rubber O-rings, and both are cheap and easy to swap. This guide shows you how to find the fault and fix it.

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• Difficulty: Easy to moderate.
• Time needed: About 30 to 45 minutes once you have the right part.
• Most likely fix: a new cartridge for a spout drip, or new O-rings for a leak at the base of the spout.

Where is your mixer tap leaking from?

• Dripping from the spout when it’s off: the cartridge (the valve inside the tap body) is worn, scratched by grit or coated in limescale.
• Leaking around the lever or handle: a worn O-ring or seal on the cartridge.
• Leaking from the base of a swivel spout when the tap is running: the O-rings that seal the spout to the tap body have worn. This is very common on kitchen mixers that get swung from side to side.
• Water in the cupboard under the sink: a loose or failing flexible hose or connection underneath. See our mono mixer tap repair guide for this.

Single-lever or two-handle mixer?

Single-lever mixers have one lever that controls both flow and temperature. Inside is one large cartridge, commonly 35 mm or 40 mm across. Two-handle mixers have a separate hot and cold valve, each with its own smaller cartridge (or a washer on older taps). On a two-handle tap, find out which side is dripping first: turn off one isolation valve at a time and see which one stops the drip.

What you’ll need

• Allen keys and small screwdrivers
• Adjustable spanner, with the jaws wrapped in a cloth to protect the chrome
• A replacement cartridge or O-rings that exactly match the old ones
• Silicone tap grease and a limescale remover or white vinegar

How to fix a mixer tap dripping from the spout

1. Turn off both supplies. A mixer is fed by hot and cold, so close both isolation valves under the sink (a quarter turn with a flat-head screwdriver). Open the tap to check the flow has stopped, and put the plug in.
2. Take off the lever. Look for a small grub screw at the back or underneath the lever, or under a coloured cap on top. Loosen it with an Allen key and lift the lever off.
3. Remove the cover. Unscrew the decorative dome or shroud by hand, then undo the brass retaining nut with your spanner.
4. Lift out the cartridge. Take a photo first so you know which way round it sat. Note any lugs that line it up in the tap body.
5. Clean or replace. Check the rubber seals on the bottom of the cartridge and clean off any limescale or grit. If the tap was only dripping slightly, cleaning and refitting can be enough. If it still drips, fit a new cartridge.
6. Reassemble. Seat the cartridge on its locating lugs, tighten the nut firmly but not hard, refit the cover and lever, then turn the water back on slowly.

How to buy the right mixer tap cartridge

Cartridges that look the same can differ by a few millimetres, and a near-miss will leak. Check the diameter, the height, the shape of the spindle (and the number of splines if it has them) and the position of the lugs on the base. The easiest way is to take the old cartridge to a plumbers’ merchant, or search for the tap’s brand and model number to buy the manufacturer’s own part.

How to fix a leak at the base of a swivel spout

If water seeps out around the bottom of the spout when the tap is running, the spout O-rings have worn. On many kitchen mixers the spout simply lifts off once you’ve loosened a grub screw or unscrewed a collar at its base. Turn off both supplies, take the spout off, roll off the old O-rings and fit identical new ones with a light coat of silicone grease, then push the spout back on and tighten the screw or collar. Spout designs vary a lot between brands, so check the tap’s instructions if it doesn’t come apart easily.

How much does a mixer tap repair cost?

Fantastic Services’ 2026 price guide puts a ceramic cartridge at about £10 to £30 and an O-ring at about £1 to £5, with a plumber charging roughly £60 to £110 to replace a mixer tap cartridge. Branded cartridges can cost more. If your tap is cheap and the cartridge is hard to find, a new tap may be better value.

Common mistakes

• Turning off only one supply. Water from the other side will still come through the tap.
• Buying a cartridge by guesswork. Match the old one exactly.
• Overtightening the retaining nut. Too much force can crack the ceramic discs or make the lever stiff.
• Losing the grub screw. Keep the plug in the sink.

Frequently asked questions

Why is my mixer tap dripping after I turn it off?

Usually the cartridge can no longer seal, because the ceramic discs are scratched, coated in limescale or the seals under the cartridge have worn. A short drip just after turning the tap off can also be water draining from the spout, which is normal if it stops within a few seconds.

Can I fix a mixer tap without replacing it?

Yes, in most cases. A new cartridge or O-rings fixes the vast majority of mixer tap drips and leaks for a fraction of the cost of a new tap.

How long do mixer tap cartridges last?

It depends on the quality of the tap and your water. Cartridges tend to fail sooner in hard water areas, which cover much of England, because limescale builds up on the discs and seals.

My lever mixer drips but only on hot. Why?

Hot water speeds up limescale and wear on seals, so the hot side often fails first. On a single-lever tap one cartridge handles both, so replace the whole cartridge. On a two-handle mixer, replace the hot side only.

More tap fixes: How to Fix a Dripping Tap (all tap types) · Mono Mixer Tap Repair · Ceramic Tap Leaking? · Dripping Bath Tap?