DIY GUIDE · PLUMBING & HEATING

How to replace a kitchen mixer tap yourself
A morning. €83–€251 for a mixer, a pair of isolating valves, tails if needed and a backnut wrench.

Same sink, same pipes, new mixer. Check your hot supply suits the tap, isolate, swap, flush, test — and leave the cylinder and the boiler alone.

DIFFICULTY
Moderate
part of the job only
TIME
Two to four hours
most of it spent getting the old tap off; the new one goes on quickly
MATERIALS
€83–€251
a mid-range mixer, two isolating valves, longer tails if the supplied ones fall short
A PRO CHARGES
€90–€220
typically €140
  • Every step, start to finish
  • Checked October 2026 — sources at the end
  • Honest about when to call a pro

FIRST, THE HONEST ANSWER

Do it yourself, or get a fitter?

Do it yourself if…

  • The new mixer fits the hole that is already in your sink or worktop, and both supply pipes already come up inside the unit
  • You know where your stop valve is, and you have proved it turns off fully, or there are working isolating valves under the sink
  • You have checked how your hot water reaches the kitchen and the new tap's sheet says it works on that kind of supply
  • The existing pipes end in compression nuts, push-fit fittings or threaded valves that you can see and reach

Get a pro if…

  • The sink is being moved, a new hole is needed in stone or composite, or the pipes have to be lengthened or rerouted
  • Your stop valve is seized, missing, or weeps when you turn it
  • Anything near the hot cylinder, the immersion or a gas boiler would have to be touched to finish the job
  • The old tap's backnut has corroded onto its tail high behind the bowl and will not move with a proper wrench

Safety first

  • Turn the water off and open the old tap to empty it before you undo anything. A tail opened under mains pressure soaks the cupboard and you.
  • The hot side can scald. Switch off the immersion and any boiler heating the water first, and let the hot run cold.
  • Unplug or switch off any appliance in or beside the unit, such as a dishwasher or a water softener, before water can reach it.
  • Lying in a sink unit with your arms above your head strains the neck and lower back. The HSA's manual handling guidance treats posture, stooping and rest as risks alongside weight; here that means a cushion under your back, short spells and getting out to stretch.
  • Wear safety glasses while you work above your face; scale and grit drop straight down as nuts come loose.
  • Nothing in this job touches gas. If a gas boiler heats your hot water, leave its case, its pipes and its controls alone.

Stop here: Stop here: gas, the cylinder and the public side of the supply

If a gas boiler heats your water, any work on it, its pipework or its controls is gas work, and in Ireland the law allows only a Registered Gas Installer to do it; the CRU runs the scheme and prosecutes unregistered gas work. The hot cylinder and immersion are a plumber's job, and anything on the immersion's wiring is electrical work for a Registered Electrical Contractor. The pipes and fittings inside your home and boundary are yours to look after, but the meter and the outside stop valve are on the public side: if the supply has to be turned off there, contact Uisce Éireann rather than opening the box. How to hire a tap fitter →

MATERIALCOVERAGEFOR THIS JOB
Kitchen mixer tapPressure range on its sheet must match your hot and cold supplyOne, with its fixing kit and tails
Isolating valvesHalf-inch or 15mm to match your pipe, screwdriver or lever operatedTwo, if none are fitted now
Flexible tap tailsOnly if the supplied tails are too shortTwo, long enough to reach in a loose curve
PTFE tapeOnly on a tapered thread that has no washer or O-ringA few wraps; never on a compression olive

How long the tails need to be

Tail length = the drop from the underside of the tap to the valve outlet, plus the sideways offset, plus a little slack for a curve. If the valve sits 350 mm below the tap and 120 mm to one side, a 500 mm tail reaches without strain.

A tail should hang in a gentle curve. If it is pulled straight, twisted or folded back on itself to fit, it is the wrong length; change it rather than force it.

Start with your hot supply, not the look

Open the cupboard and trace the hot pipe back as far as you can, then look in the hot press. If a copper cylinder sits there with a cold tank in the attic above it, your hot water is gravity-fed and at low pressure. One mainstream kitchen mixer we read is plain about it: it works with pressurised heaters and instantaneous heaters, and on an unpressurised storage heater it will not work at all. That same sheet asks for at least 0.5 bar of flow pressure and recommends 1 to 5 bar. If your hot is tank-fed, buy a tap that is sold and documented as suitable for low pressure, or the hot side will barely trickle.

Monobloc or two-hole

Most kitchen mixers now are monobloc: one body, one hole, two flexible tails hanging below. Older sinks often have two holes for a pair of pillar taps or a bridge mixer. Count the holes and measure their size before you buy. A monobloc on a two-hole sink needs a blanking cap for the spare hole; a two-hole mixer on a one-hole sink means drilling, which this guide does not cover.

Thickness of the worktop

Every tap lists a maximum clamping length: how thick the sink deck or worktop may be for the fixing to grip. The sheet we checked gives 60mm. A thick stone or timber worktop can exceed that, and a tap that cannot be clamped will spin in use. Measure from the top of the deck to the underside where the fixing plate will bear.

High mains pressure is a problem too

Where your cold comes straight off the mains, pressure can be high rather than low. The tap sheet we read says to fit a pressure reducer if the static pressure is above 5 bar, and gives 10 bar as the maximum working pressure. If taps in your house bang shut or the flow is fierce, ask a plumber about a reducer before fitting a new tap.

Tails and what they screw onto

Flexible tails screw into the underside of the tap and run down to your pipes. At the bottom they usually end in a half-inch threaded nut that needs a valve or adaptor to meet the pipe. Check what your pipe ends in now. If the supplied tails are too short to reach in a gentle curve, buy longer braided tails rather than adding an extra joint.

Keep the old tap until the new one has been in use and dry for a week; its fixing kit can rescue a missing washer.
Take a photograph of everything under the sink before you touch it, so you can see which pipe was hot.

THE PART THAT DECIDES THE FINISH

Before you start — what is under your sink

Empty the unit and shine a torch up behind the bowl. What you see there decides how the morning goes. Match it to one of these and do its prep first.

Isolating valves already fitted

The easy case. A small valve sits on each pipe just below the tap tails.

  1. Turn each slot a quarter turn so it lies across the pipe; that closes it
  2. Open the old tap on hot and cold to prove nothing more is coming through
  3. Keep a basin under each valve, because the tail above it still holds water
  4. Look at each valve body for green crusting or drips; replace a weeping one while everything is apart
Copper pipes straight to the tap

Common in older Irish kitchens. The tap's tails, or long copper tails, run straight up through the sink.

  1. Close the stop valve, usually under this sink or where the supply enters the house, and open the kitchen cold tap until it stops
  2. Close the valve on the cold feed from the attic tank to the cylinder if there is one, or turn off the gate valve on the pipe leaving the tank
  3. Run the hot tap until it slows to nothing and leave both taps open
  4. Plan to fit a pair of isolating valves on the pipe ends before the new tails go on
Plastic push-fit pipework

White or grey plastic pipe with push-fit elbows and valves.

  1. Isolate exactly as for copper
  2. Check that each plastic pipe end has a metal or plastic insert inside it; a compression or push-fit joint on plastic needs one
  3. Cut plastic pipe only with a proper plastic pipe cutter for a square end, never a hacksaw
  4. If you add a compression valve to plastic pipe, use the insert the fitting maker specifies, pushed fully home
An old tap seized to the sink

A backnut or fixing stud behind the bowl that has corroded in place.

  1. Spray penetrating oil on the backnut and the fixing studs the evening before, and again an hour before you start
  2. Clear the whole cupboard so you can lie square to the job with a cushion under your back
  3. Have the backnut wrench and a second spanner ready to hold the tail still
  4. If a sink is held on clips, decide now whether lifting the sink would be easier; if the worktop is stone, call a plumber instead
A dishwasher or washing machine on the same pipes

A tee or appliance valve feeds an appliance off the cold supply under the sink.

  1. Pull the appliance out a little and switch it off at the socket before water can reach it
  2. Close its appliance valve as well as the tap supply
  3. Photograph how the tee and hose connect, so you can put it back exactly
  4. Do not disturb the appliance hose unless it is in the way; if it is, undo it at the valve, not at the machine

THE JOB

How to replace the tap

  1. Set up and isolate the water

    30 min

    Empty the unit and lay old towels on its floor. Find your case in the cards above and do its isolation: close the valves, or close the stop valve and drain the pipes. Switch off the immersion, and the boiler if it heats your water, so the hot side cools. Open both sides of the old tap and leave them open. Wait a full minute: if water keeps coming, something is still on and you stop until you find it.

    • Photograph the pipework before you touch it
    • Put the plug in the sink so a dropped washer cannot vanish down the waste
    • Tell everyone in the house to leave the taps and the stop valve alone until you say

    Mistake to avoid: Trusting a stop valve you have not tested. An old valve that only half closes lets mains water spray out the moment the first tail comes loose.

  2. Prepare the space and check the pipe ends

    20 min

    This is the prep from the cards above, done with the water off. Set a basin under each joint. Look closely at where each pipe ends: a compression nut, a push-fit collar or the outlet of a valve. Make sure the stub of pipe is straight, round and long enough to take a fitting. Lay your tools on a towel within reach so you are not sitting up and down.

    • A folded towel or cushion over the cupboard edge saves your back
    • If the sink trap is in the way, undo it now and stand it in a bucket
    • Mark the hot pipe with a piece of tape so you cannot swap them later

    Mistake to avoid: Finding out halfway that a pipe end is crushed or too short. Look before you start, and buy a valve or coupling that suits it.

  3. Disconnect the old tap

    20 min

    Undo each tail where it meets the valve or pipe, holding the valve body with one spanner while you turn the nut with the other. Let the water drain into the basin. On a monobloc, the tails stay attached to the tap; on older pillar taps, undo the connector nut at the base of each tap tail. Keep track of which pipe was hot.

    • Turn the nut anticlockwise as you look up at it from below, which is easy to get backwards
    • Keep the old washers and olives in a bag until the new tap is in, in case you need to compare sizes
    • If a nut will not move, add a second spanner on the fitting rather than more force on one

    Mistake to avoid: Turning the nut with one spanner and nothing holding the valve. The pipe twists in the wall, a hidden joint breaks, and the job gets much bigger.

  4. Free the tap from the sink

    30 min

    Reach up behind the bowl with the backnut wrench and undo the fixing: a single large nut on older taps, or a stud with a nut and a horseshoe plate on monoblocs. Work it a quarter turn at a time. Lift the old tap out from above and clean the deck around the hole with a scraper and a damp cloth, so the new seal sits on a flat, clean surface.

    • Penetrating oil needs time to work; give it a few minutes between attempts
    • Wear safety glasses, because grit and old limescale fall straight into your face
    • If the tap spins as you turn, have someone hold the spout from above

    Mistake to avoid: Hammering or levering the tap out. A cracked ceramic sink or a chipped composite edge is a new sink, not a new tap.

  5. Fit the tails to the new tap

    15 min

    Before the tap goes into the sink, screw the flexible tails into its underside by hand. They seal on an O-ring at that end and need no tape and no spanner. Then fit the base seal and the O-ring that the maker supplies under the tap body, in the order its diagram shows. Feed the tails down through the hole one at a time, so they do not tangle or pinch.

    • Read the sheet to see which tail is which; the one we read puts cold on the right and hot on the left
    • Keep the tails clean and capped until the moment they connect
    • Thread a tail by hand all the way; if it binds, back it off and start again

    Mistake to avoid: Using a spanner on the tails where they enter the tap body. That end seals on an O-ring, and overtightening tears it or cracks the thread.

  6. Fix the tap firmly in the deck

    15 min

    From below, fit the support plate and washer onto the fixing stud and run the nut up by hand. Look at the spout from above, square it to the sink, then tighten the nut with the tool supplied or the backnut wrench until the tap does not move when you push the lever. Check it again once the tails are on.

    • Tighten in stages and glance at the spout each time, because the body creeps round as the nut bites
    • A thin worktop may need the support plate; a thick one may need it left out, as the tap's sheet explains
    • If the tap still rocks, the deck is too thick for the fixing; stop and buy a longer stud

    Mistake to avoid: Leaving the fixing slightly loose. The tap works for a week, then starts to swivel, and every swivel flexes the tails underneath.

  7. Fit isolating valves if you have none

    30 min

    If your pipes ran straight to the old tap, this is the moment to add a valve on each one. Slide the nut and a new olive onto the pipe, push the valve fully onto the pipe, and tighten the nut by hand. Then hold the valve body still and give the nut the extra turn the fitting maker allows. On plastic pipe, push the correct insert into the pipe end first.

    • Fit the valves where you can reach the slots later with a screwdriver
    • Never reuse an old olive; it has already been crushed to the shape of another fitting
    • A light smear of jointing compound on the olive is better than tape, which stops it seating

    Mistake to avoid: Putting PTFE tape on a compression olive. The olive cannot bed down evenly and the joint weeps slowly into the cupboard.

  8. Connect the tails to the valves

    15 min

    Bring each tail down in a gentle curve to its valve. Start the nut by hand, checking the washer is in place, then tighten it firmly with a spanner while you hold the valve still. Hot tail to hot pipe, cold to cold, as your photograph and the tape mark show.

    • If a tail is pulled tight or kinked, swap it for a longer one now
    • Keep tails away from sharp edges inside the cupboard
    • Look at each connection again with the torch before the water goes on

    Mistake to avoid: Stretching a tail straight to reach. A braided tail under tension fails at the crimp, and it usually lets go while nobody is home.

  9. Flush, turn on and check for leaks

    20 min

    Take the aerator off the spout if it unscrews. Open the stop valve or isolating valves slowly, a little at a time, with the lever open to mixed, and let the water run until it is clear. Grit from the pipes is the commonest reason a new tap drips. Then close the lever and run a dry tissue round every joint you touched. Look again after ten minutes and once more before bed.

    • The tap maker's sheet says to flush the pipes before and after fitting; it saves the cartridge
    • Turn the immersion and boiler back on only once the hot side runs freely
    • Put a dry sheet of kitchen paper on the cupboard floor overnight; any drip shows by morning

    Mistake to avoid: Opening the water fully and walking away. Open slowly, stand there, and watch every joint for the first few minutes.

  10. Finish and tidy

    15 min

    Refit the aerator and the sink trap if you took it off, then run the hot and cold separately. The lever should go full hot one way and full cold the other. Refit the appliance hose if you moved it. Put the tap's instructions and any spare O-rings in a bag taped inside the cupboard door.

    • Check the flow on the hot side; a weak trickle means the supply is lower than the tap needs
    • Turn each isolating valve off and on once, so you know it works
    • Wipe the cupboard dry and leave the door open for a few hours

    Mistake to avoid: Assuming the hot side will improve. If it is weak on day one, the tap and the supply do not match; it will not get better.

The mistakes that show

  • Buying a mixer that needs more pressure than a tank-fed hot supply can give
  • Tightening the tails into the tap body with a spanner
  • Twisting a pipe by undoing a joint with only one spanner
  • Reusing an old olive on a compression fitting
  • Pulling a flexible tail straight or kinking it to make it reach
  • Skipping the flush, so grit from the pipes ruins the new cartridge

Stop here and get a plumber

  • The pipework has to be moved, lengthened or teed into to reach the new tap
  • The stop valve will not close fully, or it leaks when you turn it
  • Anything on the hot cylinder, the immersion or the boiler would need to be touched
  • A new hole has to be cut in a stone, composite or ceramic sink or worktop
  • The supply in the footpath or at the meter box needs to be turned off
How to hire a tap fitter →

New tap dripping from the spoutGrit from the pipes has lodged in the cartridge. Isolate, take off the lever as the tap's sheet shows, lift out the cartridge, rinse it and refit it. Flushing before you fit the aerator prevents it.
Water leaking where the tail meets the valveThe nut needs a little more with two spanners, or the washer is missing or twisted. Isolate, undo, check the washer and remake it.
Leak from under the base of the tap on the worktopThe base seal is not seated, or the fixing nut has worked loose. Tighten from below with the spout held square; if water still gets under, lift the tap and reseat the seal.
Hot side only tricklesThe hot supply is below the tap's minimum, or a valve is only partly open. Open the valve fully. If your hot water is gravity-fed from an attic tank, the tap probably needs changing for a low-pressure model.
Hot comes out on the cold sideThe tails are on the wrong pipes. Isolate and swap them at the valves.
Tap swivels on the sinkThe fixing nut is not tight against its plate, or the deck is thicker than the tap's clamping length. Tighten from below; if it still moves, fit a longer stud.
Banging when the lever closesWater hammer, usually high mains pressure and a loose pipe. Clip any loose pipes in the cupboard; if it persists, ask a plumber about a pressure reducer.
Spout sputters and spitsAir in the pipes after draining, or a blocked aerator. Run the tap for a few minutes; if it continues, unscrew and clean the aerator.

WHAT YOU SAVE

What it costs to do it yourself

Kitchen sink mixer€64.99–€189.99
Pair of isolating valves, screwdriver type€5.29 each
Longer flexible tails, if needed€12.49–€21.59 each
Tap backnut wrench€7.39
Total€83–€251
DIY total€83–€251
A tap fitter charges per tap
LOW
€90
TYPICAL
€140
HIGH
€220
Tap & Mixer Installation price guide →

Guide prices compiled by the Locufy team from published Irish and UK provider price lists and 2026/27 cost guides. Updated 2026.

Against a plumber's guide price for fitting a tap, the saving is real but not huge, because the tap is the biggest cost either way. The wrench and the valves stay with the house.

RATHER NOT?

Tap fitters near you, with prices shown

The ones who cover your area, nearest first, with one score from every review. No account needed to look.

Or post the job free and let them come to you.

Keep the instructions and spares

Put the tap's leaflet and any spare O-rings in a bag taped inside the cupboard door. The page on changing the cartridge is the one you will want in a few years.

Clean the aerator

In a hard-water area, unscrew the aerator every few months and soak it in white vinegar. A spout that sprays sideways is usually a scaled aerator, not a faulty tap.

Get rid of the old tap

An old tap is mostly brass and plated metal, which the metal skip at your local civic amenity site will take; mywaste.ie shows what your nearest recycling centre accepts. Put old valves and tails in the same bag, and the plastic packaging in your recycling bin.

Work the isolating valves

Turn each valve off and on again a couple of times a year. A valve left alone for years seizes and is useless on the one day you need it.

Replacing a kitchen mixer tap like for like: questions people ask

Yes, if the new tap goes into the same hole on the same sink and connects to the existing hot and cold pipes. Moving pipes, adding supplies or touching the cylinder or a gas boiler is a professional's job.

Most likely your hot water is gravity-fed from a tank in the attic and the tap needs more pressure. One mixer we read asks for at least 0.5 bar and says it will not work on an unpressurised storage heater. Choose a tap sold for low-pressure systems.

Only if there are no isolating valves under the sink. With valves, close them with a flat screwdriver. Without them, close the stop valve inside the house and drain the pipes, and fit valves while it is apart.

No. Tails seal on an O-ring at the tap and on a washer at the valve. Use tape only on a tapered thread with no washer, and never on a compression olive.

The pipes inside your boundary are yours. The meter and the outside stop valve are on the public side; report a problem there to Uisce Éireann and do not open the box yourself.

Locufy's Irish price guide puts tap and mixer installation at €90–€220 per tap, typically €140. A tap that needs new pipework or a new hole costs more.

MORE GUIDES

More DIY guides

Plumbing in a washing machine or dishwasherReplacing a basin waste and trapFixing a dripping tap or a weeping jointDoing the small plumbing jobs yourselfSealing a bath or showerHandling a plumbing emergency until help arrivesBleeding radiators and re-pressurisingUnblocking a sink, bath, toilet or outside drain
All 90 DIY guides →How to hire a tap fitter →Tap & Mixer Installation price guide →Tap fitters on Locufy →

Sources — checked October 2026

  1. GROHE — single-hole kitchen sink mixer installation instructions: pressure range, clamping length, flushing
  2. HSA — guide to the manual handling of loads (General Application Regulations 2007)
  3. CRU — RGI and Safe Electric schemes: gas work is restricted to a Registered Gas Installer
  4. CRU — water leaks in the home and the First Fix Free scheme
  5. MyWaste.ie — DIY equipment: metal items at civic amenity sites
  6. Woodie's — kitchen taps (price check)
  7. Woodie's — valves and immersion fittings (price check)
  8. Woodie's — plumbing tools and accessories (price check)
  9. Woodie's — waste plugs, chains and flexible hosing (price check)