How to replace a kitchen tap without calling a plumber

What you need

• Basin wrench (tap fitting spanner with T-handle) or 10 and 11 mm box spanner
• 17 mm open-ended spanner and an adjustable spanner
• Head torch or phone torch
• Small bucket and rags
• Stanley knife and plastic scraper
• WD-40 penetrating oil in case the nut is rusted
• Single-lever kitchen mixer tap with 3/8 inch flexible hoses included (Grohe Eurosmart, Tres Max, Roca L20 or Leroy Merlin / Bricodepot own brand, 40 to 150 €)
• 3/8 by 1/2 inch flexible hoses, 50 cm, if the supplied ones are short (3 to 6 € each)
• Two 1/2 by 3/8 isolation valves with washers, if there are none (5 to 8 € each)
• 1/2 to 3/8 reducers if the valves are 1/2 inch
• Cleaning vinegar for the limescale around the tap hole

Step by step

1. 1

   Turn off the water and release the pressure

   Close both isolation valves under the sink by turning clockwise to the stop. Open the old tap on hot and cold until no more water comes out. If there are no valves or they will not close, shut off the mains stopcock for the flat.

2. 2

   Empty the cupboard and set up

   Take everything out from under the sink, put the bucket under the hoses and position the torch. If the trap is in the way, unscrew the nut at the bowl and move it aside; it is plastic and comes off by hand.

3. 3

   Disconnect the flexible hoses

   With the 17 mm spanner, loosen the hose nuts at the isolation valves. A little water will come out: let it fall into the bucket. If the hoses are stuck with limescale, hold the isolation valve with the adjustable spanner so it does not turn.

4. 4

   Loosen the fixing nut

   Find the brass nut or the threaded stud under the base of the tap. Fit the basin wrench and turn anticlockwise. If it does not give, spray WD-40, wait 10 minutes and try again. Once loose, remove the nut and the horseshoe plate.

5. 5

   Lift out the old tap and clean the base

   Pull the tap upwards, feeding the old hoses through the hole. Scrape off the old rubber gasket and the limescale around the hole with the scraper and vinegar. Dry thoroughly.

6. 6

   Prepare the new tap

   Screw the new hoses into the base of the tap by hand, no tools, no PTFE, until they stop (if the tap has two of different lengths, the short one usually goes to hot). Fit the rubber gasket on the base of the tap. Pass the stud or threaded tube through the hole together with the hoses.

7. 7

   Fix the tap from below

   From inside the cupboard, fit the gasket, the horseshoe plate and the nut onto the thread. While someone holds the tap from above, lined up with the bowl, tighten the nut with the basin wrench until the tap no longer turns. Do not go beyond that: the sink base dents.

8. 8

   Connect the hoses and open the water

   Screw each hose onto its isolation valve (hot on the left, cold on the right) hand tight plus a quarter turn with the 17 mm spanner, without twisting the flexible part. Remove the aerator, open the isolation valves slowly and let the water run for a minute. Check all four nuts and the base with dry paper. Refit the aerator.

Before replacing a kitchen tap: what to buy

Almost every sink has a standard 35 mm hole, and almost every single-lever kitchen mixer fits it. Measure the hole if the sink is old or tiled-in. Choose the spout to suit the sink: a high or swivel spout for double bowls, a low spout if there is a window or a cupboard directly above, and a pull-out spray if you do a lot of washing up by hand. Check the clearance inside the base unit: some kitchen taps have a counterweight or a spray hose that needs 40 cm of free space.

Brands with spares that are easy to find in Valencia and Alicante: Grohe (Eurosmart, Start), Tres (Max, Base), Roca (L20, Victoria), Teka and the own-brand ranges at Leroy Merlin and Bricodepot. A 40 to 60 € tap with a standard 35 mm cartridge can be repaired with universal parts for 10 years; a 20 € no-name tap usually ends up in the bin at the first drip.

The flexible hoses come with the tap, usually 3/8 inch and 35 or 45 cm long. Measure the distance from the base of the tap to the isolation valves: if the supplies in your kitchen sit very low, buy 50 cm hoses. If your isolation valves are 1/2 inch, you will need two 1/2 to 3/8 reducers (1 € each).

What you will find under the sink

In kitchens refitted in the last 20 years, two isolation valves (one per supply), sometimes with a third for the dishwasher or washing machine. Close them fully. If they will not turn, do not force them: close them by hand as far as they go and shut off the mains stopcock for the flat; a snapped isolation valve on a Sunday afternoon is an expensive upset.

In kitchens from the 70s and 80s, very common in the centre of Valencia, Alicante, Elche or Alcoy, there may be no isolation valves at all: the hose comes straight off an elbow in the wall. In that case shut off the mains and fit new 1/2 by 3/8 isolation valves with washers while you change the tap; they are 5 € each and save you cutting the water to the whole flat next time.

The tap is held by a brass nut with a horseshoe plate that clamps against the underside of the sink, or by a threaded stud with nut and washer. It sits 15 or 20 cm deep, behind the trap, in a gap your hand barely fits into. That is why the basin wrench exists (a tap fitting spanner, 8 to 15 €): a long box spanner with a T-handle. Buy one; you will not reach with an ordinary spanner.

Common mistakes when replacing a kitchen tap

The most expensive mistake is wrapping PTFE tape or hemp on the flexible hoses. Flexi hoses seal with a flat rubber washer inside the nut; PTFE only makes the thread cross so the washer cannot seat. Hand tight plus a quarter turn with the spanner, nothing more.

The second is twisting the hose as you screw it on. If you turn the hose with the nut, the steel braid tightens and the inner rubber splits within months. Hold the flexible part with your other hand and turn only the nut. And do not bend the hose in a radius under 5 cm; if there is spare length, make a wide curve.

The third is forgetting the rubber gasket between the base of the tap and the sink. Without it, splashed water runs down through the hole and floods the cupboard; on a chipboard worktop that means a swollen worktop within a year. And the fourth is shutting the new tap off hard: ceramic cartridges close without force.

• Remove the aerator from the new tap before you open the water: the first flow carries bits of PTFE, grit and limescale from the pipework.
• Hot on the left, cold on the right: follow the convention when connecting the hoses.
• Keep the box and the tap's reference: you will need the model to buy the cartridge in a few years.

When to call a professional

Call us if the old tap's nut is rusted and will not give, if there are no isolation valves and the wall supplies are old iron, if the sink is tiled-in with a wall-mounted tap, or if the isolation valve starts dripping from the spindle when you close it. Also if the base unit is full of washing machine and dishwasher pipes and there is no room to work.

The Manitas Costa plumber replaces a kitchen tap for 45 to 80 € in labour, with a tap you have bought or one we bring. That includes fitting isolation valves if there are none (plus the cost of the valves) and taking away the old tap. We arrive in 20 to 45 minutes in Valencia, Alicante, Torrevieja and Benidorm and in 30 to 60 in Dénia, Jávea, Calpe and Altea. Fixed price on WhatsApp from a photo of the space under the sink, 6-month written guarantee and an invoice with IVA (VAT). More rates in how much a plumber charges.

Limescale and salt air: tips for kitchen taps on the coast

With the hard water in Alicante and Valencia, the aerator on a kitchen tap clogs within two or three months and the stream starts coming out crooked. Unscrew it (by hand, or with a rag and the adjustable spanner), leave it in vinegar for half an hour and refit it. If the tap has a pull-out spray, do the same with the spray head.

In homes on the seafront (Torrevieja, Santa Pola, Benidorm, Dénia), salt air attacks the chrome and the brass nuts under the sink. A brushed stainless steel finish holds up better than bright chrome, and a hose with stainless steel braid outlasts a galvanised one. If the old tap is only dripping, before you replace it see how to fix a dripping tap; and if the lever has no visible screw, how to take apart a single-lever tap.