How to Change Bathroom Taps

How to Change Bathroom Taps

Changing bathroom taps is one of the more achievable plumbing jobs a confident DIYer can do in the UK, but it has a specific difficulty that most guides underplay: the access. Fitting new taps takes twenty minutes when the isolation valves are easy to reach and the tap connectors undo cleanly. It takes two hours when the space under the basin is tight, the old fittings have seized, or there is no isolation valve and you need to find the mains stopcock instead. Working out which situation you are in before you buy anything saves a lot of time and frustration.

The tap itself is almost never the hard part. What actually determines how long the job takes is what is already under the basin and how much of it has corroded or seized over the years.

Check What You Have Before Buying Anything

Most bathroom taps fail at the buying stage, not the fitting stage. People choose a tap they like the look of and discover on arrival that the hole centres do not match, the tail length is wrong for the basin depth, or a monobloc mixer will not fit a basin drilled for two separate taps.

Three things to confirm before purchasing:

Number of holes. A basin drilled for two separate taps has two holes roughly 180 mm apart. A basin drilled for a monobloc mixer has one central hole. Some basins have a third hole for a separate handspray or overflow, and some have none at all and are wall-mounted. Count before buying.

Hole centres. If you are replacing two separate taps with two new separate taps, measure the centre-to-centre distance. Standard UK spacing is 180 mm, but older or continental basins sometimes differ. A monobloc with a 180 mm centre plate bridges standard spacing, but confirm before ordering.

Tail length and thread. The tails that drop through the basin hole need to be long enough to reach the supply pipes below, with enough thread exposed for the backnuts to tighten against the underside of the basin. Deep ceramic basins need longer tails than standard. Most modern UK taps use 15 mm compression or push-fit connectors, but older installations may have 3/4 inch BSP. Check before ordering flexible tails.

Tools You Will Need

An adjustable spanner or basin wrench is non-negotiable. A standard adjustable spanner will not reach the backnuts in a tight pedestal basin. A basin wrench, a long-handled tool with a swivelling jaw specifically designed for this access problem, is the right tool. Hiring one from a local tool hire shop costs £8 to £15 per day if you do not want to buy.

You will also need: PTFE tape, a bucket to catch residual water, a towel to lay on the floor under the basin, and a torch or head torch, because the space under most pedestal basins is dark and cramped.

Step 1: Turn Off the Water Supply

Find the isolation valves on the supply pipes under the basin. These are small inline valves, usually with a single screw slot. Turn the screw 90 degrees so the slot is perpendicular to the pipe and the flow is closed. Then turn the taps on to release pressure and confirm the water has actually stopped.

If there are no isolation valves under the basin, you need to turn off the mains at the household stopcock, usually under the kitchen sink or where the supply enters the house. This affects water to the whole property, so plan accordingly. While you have the isolation valves visible, note their condition: a seized or weeping isolation valve is worth replacing at the same time, since access is already there and a failed valve causes the same problem as no valve at all.

Step 2: Disconnect the Supply Pipes

Place the bucket under the supply connections before undoing anything. Even with the supply off, the pipes hold residual water.

Undo the compression nuts or push-fit connectors joining the supply pipes to the tap tails. Compression nuts unscrew anticlockwise. If they have not moved in years, a gentle application of penetrating oil left for ten minutes makes a significant difference. Do not use excessive force on older copper pipework, which can distort or crack at the olive if it is torqued at the wrong angle.

Keep the supply pipes from dropping back into the cavity or pedestal. Taping them temporarily to the basin or pedestal keeps them accessible for reconnection.

Step 3: Remove the Old Taps

From above, remove any decorative covers or tap tops to expose the tap body fixing. From below, undo the backnut or mounting nut holding each tap to the basin. This is where the basin wrench earns its place: on a pedestal basin the nut sits 200 to 400 mm inside the pedestal column, and a standard spanner cannot reach it at the right angle.

Old backnuts that have not moved in a decade often require significant effort. Penetrating oil, patience, and the correct tool in the correct position are more effective than force at the wrong angle, which risks cracking the basin. Ceramic basins do not flex and will fracture under enough torsional load.

Once the backnut is off, the old tap lifts clear from above. Remove any old sealant or putty residue from the basin surface with a plastic scraper. Do not use metal tools, which scratch ceramic and acrylic.

Step 4: Fit the New Taps

Drop the new tap tails through the basin hole from above, with any gasket or sealing washer seated flat against the basin surface. On a basin without a gasket seat, run a thin bead of silicone sealant around the base of the tap body before inserting, keeping it back from the edge so excess squeezes inward rather than outward.

From below, fit the backplate or top hat washer over the tails, then thread on the backnut by hand before tightening with the basin wrench. Firm and snug is correct. Overtightening cracks ceramic basins, and the tap body being pulled hard against the surface provides more than enough seal. Half a turn past hand-tight with the wrench is usually sufficient.

Wrap the tail threads with three to four layers of PTFE tape before connecting the flexible tails or supply pipes. Wind the PTFE in the direction the fitting screws on, so tightening does not unwind it.

Step 5: Reconnect and Test

Reconnect the supply pipes to the tap tails using compression or push-fit fittings as appropriate. Compression nuts should be tightened to firm resistance plus a quarter turn, not cranked hard. Push-fit connectors seat with an audible click.

Turn the isolation valves back on, one at a time, and check each connection immediately for drips before turning on both. A weeping compression joint at this stage almost always means the olive is not seated correctly: turn off, disconnect, reseat, and reconnect. Do not attempt to stop a dripping compression joint by tightening further without checking the olive first.

Turn the taps on and off several times to check operation and confirm flow from both hot and cold. Check under the basin again after five minutes of water running, since some slow weeps only show once flow has been sustained.

When to Stop and Call a Plumber

Stop and call a plumber if the isolation valves are seized and will not turn, if the supply pipes are lead (a grey, dull metal that bends easily, common in pre-1970 UK properties), if you find signs of existing leaks behind the basin or in the wall, or if the tap you want to fit requires a pressure or flow rate that your system cannot support.

Changing taps in a UK rental property is also worth flagging. The Water Supply (Water Fittings) Regulations 1999 require that any work on the water supply system, including tap replacement, uses approved fittings and does not cause contamination or waste of water. For a straightforward like-for-like replacement this is not a practical concern, but any work that changes the configuration of the supply, adds a handheld shower attachment to a basin tap, or involves a back-siphonage risk should use a WaterSafe-registered plumber. Landlords in particular should keep records of plumbing work for compliance purposes.

If you decide to bring a plumber in, the job itself is typically one to two hours for a straightforward basin tap replacement. UK plumbers charge £40 to £80 per hour, so expect £60 to £180 for labour on a standard swap, plus any parts. If you are having a plumber visit for taps, it is worth listing any other small plumbing jobs at the same time, since call-out and travel costs are shared across the visit.

A tap change is also a natural moment to consider whether anything else in the bathroom is ready for updating. If the basin, bath panel, or tiling is looking tired alongside the taps, combining it with a broader refresh is considerably cheaper than booking separately. The InstantCost bathroom renovation cost guide has a full 2026 UK price breakdown from a small cloakroom refresh at £1,800 to £3,000 through to a full mid-range refit at £5,500 to £8,500, with a calculator you can filter by bathroom size and spec before getting quotes.

For the plumbing side specifically, our related guide covers how to change a kitchen tap, which runs through the same isolation and reconnection process for a kitchen mixer where the under-sink access is usually better than under a pedestal basin.

Common Mistakes and What to Do Instead

Mistake: buying the tap before checking the hole configuration. A monobloc mixer will not fit a two-hole basin without drilling or a cover plate. Measure the holes and spacing before ordering anything.

Mistake: not using a basin wrench. A standard adjustable spanner cannot reach the backnuts inside a pedestal basin at a usable angle. A basin wrench hire costs less than an hour of a plumber's time.

Mistake: overtightening the backnut against a ceramic basin. Ceramic does not flex. Firm plus half a turn from the wrench is enough. Continuing to tighten fractures the basin, and a cracked basin is a replacement job.

Mistake: skipping PTFE tape on the tail threads. The tape creates the seal at threaded connections. Missing it produces a slow drip that appears hours after you have cleared up and put the tools away.

Mistake: not checking isolation valves before starting. A seized isolation valve discovered after the old tap is already removed means turning off the mains with no water in the house until the job is done. Check valve operation first.

Mistake: tightening a weeping compression joint without reseating the olive. More torque on a compression joint where the olive is not correctly seated damages the olive and the pipe, and the drip continues. Disconnect, check, reseat.

Mistake: not testing under load. Running the tap briefly and checking immediately misses slow weeps that only show after several minutes of flow. Leave it running for five minutes and check underneath.

What It Costs in the UK

DIY costs are mainly the tap itself and any small consumables. Bathroom basin taps range from under £30 for basic chrome single taps to £200 to £600 for designer monobloc mixers. A basin wrench hire runs £8 to £15 per day. PTFE tape costs under £2. Flexible tap tails, if replacements are needed, run £5 to £15 per pair.

If a plumber is doing the work, UK plumbers charge £40 to £80 per hour in 2026. A straightforward basin tap swap typically takes one to two hours, putting the labour cost at £60 to £160. Replacement of isolation valves at the same time adds roughly £30 to £60 in parts and a small amount of additional labour.

Figures based on InstantCost.co.uk's 2026 UK bathroom and plumbing pricing data and vary by region, access difficulty, and provider.

Staying Safe

Tap replacement is low-risk by plumbing standards, but two things deserve attention.

Water damage from a failed connection is the main practical risk. Always have a bucket positioned before disconnecting anything, keep towels available, and check connections before walking away. A slow drip behind a pedestal or into a wall cavity that goes unnoticed for days causes far more damage than the immediate cost of the taps themselves.

The second thing is lead pipework. Pre-1970 UK properties, and some built into the early 1970s, may have lead supply pipes. Lead is a health hazard and any work that disturbs lead pipework should be done by a professional. If you are unsure, run water for 30 seconds before use and consider a water filter certified to remove lead as an interim measure while you investigate further.

Keep children and pets out of the work area during the job. Penetrating oil sprays are flammable and irritating to skin and eyes. Work in a ventilated space if using any spray products, and wash hands thoroughly after handling old tap fittings, which may carry scale and mineral deposits.

If you discover any signs of existing water damage, black mould, or soft flooring around the base of the basin, stop the job and investigate the source before proceeding. Fitting new taps over an existing slow leak solves nothing and hides a problem that will worsen.

Water Supply (Water Fittings) Regulations 1999 require that plumbing work in the UK uses approved fittings and does not cause contamination, waste, or misuse of water. A like-for-like tap replacement by a competent person meets this requirement without formal notification. Any work that changes the supply configuration, including adding a handspray or altering the hot/cold arrangement, should use a WaterSafe-registered plumber. Check current regulations at waterplc.com or dwi.gov.uk before starting any work beyond a straightforward swap.

FAQ

Do I need a plumber to change bathroom taps in the UK? Not for a straightforward like-for-like replacement. The Water Supply (Water Fittings) Regulations 1999 allow competent persons to carry out standard tap swaps without formal notification. Any work that changes the supply configuration should use a WaterSafe-registered plumber.

How long does it take to change bathroom taps? One to two hours for a straightforward swap with good access and functioning isolation valves. Allow an extra hour if the backnuts have seized or if the isolation valves need replacing.

What tool do I need to remove bathroom taps? A basin wrench is essential for pedestal basins where backnuts sit 200 to 400 mm inside the pedestal column at an angle no standard spanner can reach usefully. Hire one for £8 to £15 rather than buying if you only need it for one job.

Can I replace two separate taps with a monobloc mixer? Only if the basin has a single central hole, or if the existing two holes are spaced to accept a monobloc cover plate. You cannot drill a ceramic basin at home without a specialist diamond-tipped hole saw and significant risk of cracking. Check the configuration before buying.

How much does a plumber charge to change bathroom taps? UK plumbers charge £40 to £80 per hour in 2026. A standard tap swap takes one to two hours, so expect £60 to £160 in labour. If isolation valves need replacing at the same time, add £30 to £60 in parts.

What if my isolation valves are seized and will not turn? Do not force them. Turn off the mains stopcock instead, then replace the isolation valves as part of the job. A seized isolation valve that is forced and fails partway through the job leaves you with a flooded bathroom and no easy way to stop it.