How to Fix a Leaky Tap
Last updated: May 2026 · Reviewed quarterly
I have fixed leaky taps in three different houses now. It is genuinely one of the easiest plumbing jobs — 30 minutes, a few quid in parts, and that maddening drip is gone.
Difficulty
Easy
Time
30 minutes
Cost
£5 - £20
Before You Start
Always turn off the water supply before working on taps. Close the isolation valve under the sink (turn clockwise with a flat-head screwdriver) or turn off the stopcock, usually under the kitchen sink. Open the tap to drain residual water. Put the plug in the sink so small parts cannot fall down the drain.
A dripping tap wastes around 5,500 litres of water per year and will stain your sink or bath over time. The first time I fixed one, I was surprised how straightforward it was. The cause is almost always a worn washer or ceramic cartridge, both of which are cheap and easy to replace. The first step is identifying what type of tap you have.
What You Will Need
Tools
- - Adjustable spanner
- - Flat-head and cross-head screwdrivers
- - Long-nose pliers
- - Old towel or cloth
Materials
- - Replacement washer or ceramic cartridge (take the old one to the shop to match)
- - Plumber's grease (silicone-based)
- - PTFE tape
Step 1: Turn Off Water Supply
Locate the isolation valve beneath the sink. Turn the slot with a flat-head screwdriver so it sits across the pipe.
Step 2: Remove Tap Handle
Pop off the hot/cold indicator cap with a flat screwdriver, remove the screw underneath, and lift off the handle.
Step 3: Replace Washer or Cartridge
Prise off the old washer from the jumper valve and press on a new matching replacement.
Step-by-Step Instructions
Identify Your Tap Type
Compression taps (traditional, separate hot and cold) use rubber washers. Quarter-turn taps use ceramic disc cartridges. Mixer taps may use either, or a single cartridge. If the tap turns multiple times from off to full, it is a compression tap. If it turns only a quarter turn, it has ceramic discs.
Turn Off the Water
Close the isolation valve under the sink. Turn the slot with a screwdriver so it sits across the pipe (perpendicular = off). If there is no isolation valve, turn off the main stopcock. Then open the tap to release remaining pressure and water.
Remove the Tap Handle
Prise off the decorative cap (the hot/cold indicator) with a flat screwdriver. Underneath is a screw - remove it. Lift off the handle. Some modern taps have a small grub screw on the side instead.
Remove the Headgear or Cartridge
For compression taps: use a spanner to unscrew the headgear (the brass body under the handle) anticlockwise. The washer is on the bottom of the jumper valve. For ceramic disc taps: unscrew and pull out the cartridge.
Replace the Worn Part
For compression taps: prise off the old washer and press on a new one of the same size (typically 1/2 inch for basin taps, 3/4 inch for bath taps). For ceramic disc taps: replace the entire cartridge. Take the old one to a plumbing supplier to get an exact match.
Reassemble
Apply a thin layer of silicone grease to the threads and O-rings. Screw the headgear or cartridge back in. Hand-tighten first, then a quarter turn with a spanner - do not overtighten or you will damage the seat. Refit the handle and decorative cap.
Test
Turn the water supply back on slowly. Check for leaks around the headgear. If the tap still drips, the tap seat may be damaged and needs re-grinding with a seat reseating tool, or the whole tap may need replacing.
Pro Tip: Take Photos
Before you start dismantling, take photos of the tap assembly at each stage. This makes reassembly much easier, especially with unfamiliar tap designs.
Pro Tip: Protect the Finish
Wrap the jaws of your spanner with masking tape or a cloth to avoid scratching chrome or brushed steel finishes.
Common Mistakes to Avoid
- - Forgetting to turn off the water first - obvious but easily forgotten in the moment
- - Overtightening the headgear - this damages the valve seat and makes the problem worse
- - Buying the wrong size washer - always take the old one to the shop for matching
- - Using pliers on decorative parts - they scratch and damage the finish permanently
- - Not replacing O-rings while you are in there - they cost pennies and prevent future leaks
When to Call a Professional
If the tap still leaks after replacing the washer, the valve seat may be damaged. A plumber can re-grind the seat or replace the tap. Also call a plumber if you cannot find or turn off the isolation valve, or if the tap is seized and you risk snapping the pipe.