Replacing a Kitchen Tap: DIY or Plumber, and How Long It Takes

Updated July 2026 · Emergency Plumber Chelsea

Replace or repair? If the tap drips from the spout or leaks around the swivel, a new cartridge or O-ring often fixes it for far less than a new tap. Our guide to a kitchen mixer tap leaking explains what each leak means. Replacement makes sense when the tap is corroded or scaled beyond saving, parts are no longer available, the handle is loose inside the body, or you simply want a different style or a pull-out spray. If water is collecting in the cupboard rather than on the worktop, check the hoses first; our guide to a leak under the kitchen sink covers that.

Check your water pressure before you buy. This is the step most people miss. Many modern mixer taps are designed for mains pressure and give a feeble flow on a low-pressure system. If your hot water comes from a cylinder fed by a tank in the loft, rather than from a combi or an unvented cylinder, your hot supply is gravity-fed and you need a tap rated for low pressure. Manufacturers state the minimum working pressure on the box or data sheet. Our guide to mains pressure and gravity-fed plumbing helps you tell which you have.

Mixed pressures need check valves. Where the cold is on mains pressure and the hot is gravity-fed, a mixer tap can push cold water back into the hot supply. Water regulations require backflow protection in that situation, usually single check valves on the supplies. Many taps include them in the flexible hoses or tap body, but not all. It is one reason a plumber asks what system you have before fitting a mixer.

Choosing the type of tap. A monobloc mixer with a single hole is the most common kitchen tap and the easiest to swap for another monobloc. Pillar taps use two holes, one hot and one cold. A bridge mixer uses two holes joined by a bar. Changing from pillar taps to a monobloc means blanking one hole or replacing the sink, and fitting a tap into a stone or quartz worktop with no hole means drilling it, which is a job for the worktop fitter. Pull-out spray taps need space under the sink for the hose loop and weight. Boiling water taps and filter taps need a tank or filter unit in the cupboard, and boiling water taps need an electrical supply; our guide on whether a boiling water tap is worth it covers the extra considerations.

What the job involves. Turn off the isolation valves under the sink, or the main stopcock if there are none; our guide on how to turn off a stopcock shows which way. Open the tap to release pressure. Disconnect the flexible hoses from the isolation valves. Undo the fixing nut or threaded rod under the worktop that holds the tap down, lift the old tap out and clean the surface, which is usually crusted with limescale. Fit the new tap with its base seal, tighten the fixing from below, connect the new hoses to the valves, then turn the water back on slowly and check every joint. Run the tap for a minute to flush out any debris.

Where it gets difficult. The fixing nut on an old tap sits behind the sink bowl, often right against the wall, and is frequently seized with corrosion. A basin wrench helps, but in a tight corner or with a deep sink it can take longer than the rest of the job put together. Old taps sometimes connect straight to rigid copper pipe rather than flexible hoses, which means cutting and fitting new isolation valves. Isolation valves that have not been turned for years may not shut fully or may start to drip once moved. Any of these can turn a short job into a longer one.

Flexible hoses matter. The hoses supplied with the tap connect to the isolation valves under the sink. Do not twist or kink them, keep them out of the way of the waste and anything stored in the cupboard, and tighten them firmly but without heavy force. Overtightened or kinked hoses are one of the most common causes of slow leaks under a sink, and a braided hose that fails under mains pressure can flood a kitchen quickly.

How long does it take? For a plumber, a like-for-like monobloc swap with good isolation valves usually takes around an hour, sometimes less. Allow longer for seized fixings, new isolation valves, cutting into rigid pipework, a pull-out or boiling water tap, or a change from pillar taps. A first-time DIYer should allow an afternoon, with the water off for most of it.

Hard water and your new tap. London's water is hard, and limescale is what wears out most kitchen taps. Cleaning the aerator regularly and wiping the tap after use helps the ceramic cartridge last longer. Our guide to hard water and limescale explains the options, from simple cleaning to softening.

Flats and mansion blocks. In a flat, a slipped hose or a joint left loose drips into the ceiling below, so check under the sink carefully for a day or two after fitting. If your flat has no isolation valves under the sink and the stopcock is stiff or shared, it is worth having isolation valves fitted while the tap is being changed so future jobs are simpler.

When to call a plumber. Call a plumber if there are no isolation valves, the stopcock will not turn, the old tap is fixed to rigid pipe, the tap is a boiling water or filter model, your hot water is gravity-fed, or you have tried and the joints keep weeping. Emergency Plumber Chelsea fits kitchen taps and isolation valves, checks the pressure suits the tap and leaves everything tested. See our kitchen plumbing repairs or leaking tap repair pages, or call 020 3002 6667. There is no call-out fee on jobs over 3 hours, so it is worth listing any other small jobs for the same visit.

Quick tips

• Check the tap's minimum working pressure against your hot and cold supply before buying.
• Buy a tap with the same number of holes as your sink or worktop unless you plan to change them.
• Make sure there are isolation valves under the sink before you start, or plan to fit them.
• Keep the flexible hoses untwisted and tighten them firmly, not with brute force.
• Check under the sink for drips an hour after fitting and again the next day.

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