Types of Taps and What Goes Wrong

  • Compression taps (older style, two separate handles): drip is almost always a worn rubber washer at the bottom of the valve stem
  • Ball taps (single handle that rotates): usually worn springs, seats or O-rings inside the ball mechanism
  • Cartridge taps (single or double handle, smooth action): the cartridge itself needs replacing
  • Ceramic disc taps (quarter-turn, modern): ceramic disc needs cleaning or replacing
Before you startTurn off the water supply. The isolation valve is usually under the sink — turn clockwise until it stops. If there is no isolation valve, turn off the mains supply at the stopcock. Turn the tap on to release any remaining water pressure.

Fixing a Compression Tap (Most Common)

  1. 1

    Remove the tap handle

    Prise off the decorative cap on top of the handle (usually pops off with a flat screwdriver). Unscrew the screw underneath. Lift the handle off. You may need to wiggle it if it has not been moved in years.

  2. 2

    Remove the packing nut

    Use an adjustable spanner to unscrew the large hexagonal packing nut. Turn anticlockwise. Place a cloth under the tap to catch any drips.

  3. 3

    Pull out the valve stem

    Once the packing nut is off, pull the valve stem straight out. At the bottom you will see the rubber washer held by a brass screw.

  4. 4

    Replace the washer

    Unscrew the brass screw and remove the old washer — it will be flattened, cracked or deformed. Take it to a hardware store to match the size exactly, or buy an assorted washer kit. Fit the new washer and screw the brass screw back in.

  5. 5

    Reassemble in reverse

    Refit the valve stem, tighten the packing nut, replace the handle and cap. Turn the water supply back on slowly and test.

Replacing a Cartridge

For cartridge taps, after removing the handle you will see the cartridge — a plastic and rubber cylinder. Note its orientation before removing it. Pull straight out (or unscrew if held by a retaining nut). Take it to a plumbing supplier for an exact match. Push the new one in the same orientation and reassemble.

Tap still dripping after new washer?The valve seat (the brass ring the washer presses against) may be worn or pitted. A tap reseating tool (available from hardware stores) grinds the seat flat again. Or call a plumber — seat replacement is a 10-minute job for a professional.

Frequently Asked Questions

A tap dripping once per second wastes about 30 litres per day — over 10,000 litres per year. A steady drip wastes significantly more. Beyond the water bill impact, a dripping tap also indicates increasing wear that will eventually cause a more serious failure if left unrepaired.
Call a plumber if: you cannot turn off the water supply, the leak is under the sink from a pipe joint (not the tap itself), the tap body is cracked, or after replacing the washer the tap still leaks. Replacing washers and cartridges is a reasonable DIY job — anything involving pipe joints or the mains is best left to a licensed plumber.