Repair a leaking kitchen sink tap
- Robert Costart
- May 29
- 3 min read
Updated: Jun 4
š Overview
Stopping drips from the spout or leaks around the body of a kitchen sink tap by replacing the worn washer, O-rings or ceramic cartridge and re-seating internal parts.
Skill level: 2 ā 3 / 5Ā (straightforward if fixings arenāt seized)
Typical duration: 1ā2 hĀ hands-on
ā ļø Safety First
Shut off hot and cold isolation valves (or main stopcock) before dismantling to avoid scalds and flooding.
Open the tap to depressurise the lines and prevent spray-back when loosening parts.
Sharp stainless-steel sink edges and burrs on brass cartridges can cutāwear cut-resistant gloves.
Eye protection shields against grit or limescale flakes when cleaning the valve seat.
Clear the workspace of kettles, toasters and trailing leads; water and electrics do not mix.
š§° Tools & Materials
Purpose | |
|---|---|
2 mmā5 mm Allen keys / small screwdriver | Remove handle grub screw or cap |
Adjustable spanner or cartridge socket | Undo valve/cartridge retaining nut |
Long-nose pliers | Extract circlips or tap washers |
Seat grinder (optional) | Resurface pitted compression seats |
Replacement ceramic cartridge orĀ Ā½ā rubber washer & fibre washer | Cure drip depending on tap type |
O-ring kit (spout/base sizes) | Stop leaks at swivel joints |
PTFE tape | Reseal any threaded joints |
Methylated spirits & nylon brush | Clean scale from parts and seat |
Plumberās silicone grease | Lubricate O-rings and cartridge seals |
Towels & bucket | Catch residual water under sink |
Torch & kneeling pad | Visibility and comfort in cupboard |
š Step-by-Step
1. Diagnose the leak
Action: Observe where the water emergesāspout drip, handle base, or underneath.
Why: Pinpoints whether to replace cartridge/washer (drip) or O-rings (body/spout leak).
2. Isolate and drain
Action: Close both isolation valves; open the tap fully to release pressure.
Why: A dry, pressure-free tap is safer and cleaner to dismantle.
Pro-tip: If no valves exist, wedge the sinkās waste with a rag to catch any dropped screws.
3. Remove the handle and trim
Action: Pop off the hot/cold cap, loosen the hidden grub screw with an Allen key, and lift off the handle and shroud.
Why: Exposes the cartridge retaining nut or gland.
Pro-tip: Photograph each layer as it comes offāreassembly is fool-proof.
4. Extract the valve
Ceramic-disc mixer
Action: Hold the tap body with one hand; unscrew the cartridge retaining nut with a deep socket and lift out the cartridge.
Why: The twin ceramic discs inside wear or get debris lodged, causing drips.
Compression tap (rubber washer type)
Action: Undo the gland nut, wind the spindle out and pull the jumper/washer assembly free.
Why: A perished washer lets water past even when closed.
5. Inspect and replace parts
Action: Match the old cartridge or washer size and pattern; install the new one. Replace any scored O-rings on a swivel spout.
Why: Correct parts restore watertight seals.
Pro-tip: Smear silicone grease on new O-rings and cartridge seals for smoother action and longer life.
6. Clean the valve seat
Action: Scrub mineral deposits with a nylon brush; for compression taps use a seat grinder to smooth pits.
Why: A rough seat cuts new washers and restarts the leak.
7. Re-assemble
Action: Refit the valve/cartridge and tighten snugly (do not over-torque). Replace shroud, handle and cap.
Why: Restores original alignment and finish.
Pro-tip: Wrap a single turn of PTFE on coarse male threads only to deter seepage without stressing brass.
8. Pressurise and test
Action: Open isolation valves slowly; run hot and cold for 60 s while inspecting joints and the spout.
Why: Confirms the repair before the cupboard is tidied.
Pro-tip: Leave kitchen roll under the tap overnightāany hidden drip shows as a stain.
š Completion Checks
No drip from spout after 5 min tap-off.
Dry tissue around handle base, spout swivel and under-sink flexi tails.
Smooth, light quarter-turn (ceramic) or firm stop-to-stop (compression) operation.
Spout swivels freely without sideways play.
š·āāļø When to call a pro instead
If the retaining nut is seized solid, the tap body is cracked, or your mains pressure is unbalanced and causing repeated cartridge failure, a plumber with penetrating oil, heat pads and replacement tap options can solve it without damaging the sink or pipework.