Yes, you can swap the worn seal in a kitchen mixer tap by isolating the water, opening the body, and fitting a matching washer or cartridge.
Why Your Mixer Is Dripping
A dripping spout wastes water and marks the sink. In a twin-handle mixer, the culprit is often a small rubber seal in the valve. In many single-lever mixers, the sealing parts sit in a ceramic cartridge. The fix is easy once you know which style you own.
Identify Your Tap Style First
Watch the handle travel. A quarter-turn feel points to a ceramic insert. Several turns hint at a compression valve with a rubber seal. A single lever that lifts and swings left-right usually hides a cartridge. This quick check decides the parts and steps you’ll use.
Tools And Parts You’ll Need
- Flat and Phillips screwdrivers
- Adjustable spanner or a 32 mm socket for some mixers
- Long-nose pliers
- Allen key set for single-lever caps
- Replacement seal or cartridge that suits your model
- PTFE tape for compression joints only
- Soft cloths, vinegar for scale, and silicone grease rated for potable water
Quick Reference For Common Tap Types
| Tap Style | Typical Sign | Likely Fix |
|---|---|---|
| Quarter-turn levers | Stiff action or drip | New ceramic insert |
| Twin handles, many turns | Drip or handle needs force | New rubber seal |
| Single lever mixer | Drip or poor mix | New cartridge |
Turn Off Water Safely
Find the small chrome slotted valves on the hot and cold pipes under the sink. Turn the slot so it stands across the pipe to shut each side. If you don’t have these, close the stop tap where the main enters the home. Open the mixer to confirm water is off. Leave the handles open while you work to relieve pressure. See the WaterSafe guide for stop taps and safe operation.
Protect The Sink Area
Pop up the plug, lay a towel for small screws, and tape around the chrome base to avoid scuffs. Snap a photo at each stage to make reassembly easy. Keep tools within easy reach now.
Method For A Compression Valve With A Rubber Seal
- Remove the index cap on the handle. Prise it up with a thin screwdriver.
- Loosen the small screw below the cap and lift off the handle.
- Unscrew any shroud or dome that hides the valve body.
- Use a spanner to free the valve. Turn anti-clockwise. Lift it out.
- At the bottom of the stem you’ll see the small black seal. Lever it off and fit the same size replacement.
- Check the seat inside the tap body. If it’s pitted, a fresh seal may still drip. You can fit a seat insert kit or call a plumber if the damage is severe.
- Smear a tiny amount of silicone grease on the stem threads and O-ring. Don’t overdo it.
- Refit the valve, shroud, handle, and cap. Close the mixer, then reopen the isolation valves slowly and check for leaks.
Method For A Single-Lever Mixer With A Cartridge
- Flip out the red/blue cap. Loosen the grub screw with the correct Allen key and lift off the lever.
- Remove the decorative cover. Some models have an extra insert—lift it away.
- Use the size noted by your maker (often a 32 mm socket) to undo the retaining ring or nut.
- Pull the cartridge straight up. If it’s stuck with scale, a gentle wiggle helps.
- Drop in the matching new unit, ensuring the locating lugs line up in the body.
- Tighten the ring or nut to snug, not brute tight. Refit the cover and lever, then reopen the isolation valves and test hot and cold.
Grohe shows a typical cartridge change in a short guide.
Match The Right Part
Take the old seal or cartridge to a merchant, or check the model code stamped on the body or printed under the spout. Many makers publish look-up charts that map model numbers to part numbers. A wrong part can fit loosely or lock the lever, so confirm before you buy.
Clean, De-Scale, And Rebuild
Mineral build-up can cause drips even with fresh parts. Soak the aerator in warm vinegar, then rinse. Wipe the valve seat. Keep abrasives off chrome. Before reassembly, line up parts and avoid cross-threading. Hand start every thread, then finish with tools.
Testing And Fine Tuning
Open both isolation valves slowly. With the spout over the sink, move from off to low flow, then up to full. Cycle hot and cold. Look for weeps at the base and under the sink. If you see a bead at a compression nut, give it a nip. If the lever feels gritty, reseat the cartridge and retest.
Troubleshooting Common Hiccups
Handle still stiff: The issue can be scale on the stem or a failing ceramic insert. Replace the insert and add a tiny smear of silicone grease on the stem flats.
Drip only on hot: The hot side seal or hot feed insert is worn. Replace that side first.
Drip stops when the spout is moved: The spout O-rings are worn, not the valve. Fit a new O-ring kit for the spout.
Water won’t shut off fully: The main stop tap may not be fully closed, or the seat is damaged. Inspect with a torch.
Symptoms, Causes, And Fixes
| Symptom | Likely Cause | Practical Fix |
|---|---|---|
| Drip after shut-off | Worn rubber seal or ceramic insert | Replace worn part |
| Stiff lever | Scale or failing insert | New insert and clean parts |
| Leak at base | Tired O-rings | Replace O-ring kit |
Safety And Good Practice Notes
Never force a stuck nut with a tiny wrench. Use the correct size to avoid rounding edges. Open and close valves slowly. Use PTFE only on threaded compression joints under the sink, not on tap body threads or cartridge seats. Keep harsh cleaners off rubber parts. If supply pipes look fragile, pause and call a pro.
When A Washer Isn’t The Answer
Many modern mixers don’t use a rubber seal at all. They rely on a cartridge with ceramic discs that slide to seal water. Swapping the small rubber ring won’t stop a drip in that design. If your lever turns just a quarter and stops, plan to fit a matching cartridge. Makers publish short guides that show the steps and the tool size for the retaining ring.
Washer Replacement For A Kitchen Mixer Tap—Quick Guide
A straight seal swap on a compression valve can take fifteen to thirty minutes. A clean cartridge change can be the same. Add time if you must free a stuck shroud, scrub scale, or find the stop tap in a tight cupboard. Allow an hour. Steady beats speedy in plumbing today.
Cost Of Parts And When To Call
A pair of rubber seals is cheap. A branded cartridge costs more, yet still less than a new mixer. Call a plumber if the valve seat is pitted, if the body is cracked, or if isolation valves are missing. Adding isolation valves makes every later repair easy and avoids shutting water to the whole property.
Care Tips To Prevent Drips
Don’t crank handles tight. A light turn to off is enough and saves the seat. Clear limescale from the aerator every few months. In hard water areas, a softener or inline filter helps. Cycle the isolation valves twice a year so they don’t seize. Label which way is shut so anyone can act fast during a leak.
Simple Parts Checklist Before You Shop
- Exact size and type of seal, insert, or cartridge
- New O-rings for the spout if there’s play
- Allen key size for your lever
- Retaining ring tool size
- PTFE tape for compression joints under the sink
- Food-grade silicone grease
Method Recap
Shut off water. Open the mixer to drain. Strip the handle and trim. Extract the valve or cartridge. Swap the worn part. Clean mating faces. Rebuild and test.
What Pros Wish DIYers Knew
Pictures help. Snap each stage. Keep small parts in a tray. If a shroud won’t budge, use a rubber jar opener and turn by hand before tools. If a compression valve fights you, crack it loose with a sharp pull. When threads start, they should feel smooth. Any grating feel means stop and realign.
Frequently Asked Missteps
Mixing up hot and cold during testing. Forgetting to open both isolation valves. Over-tightening the cartridge ring. Skipping the aerator clean and blaming the valve for weak flow. Using PTFE on the wrong threads. These cause leaks that get blamed on the new parts.
Where To Put Those Helpful Links
Keep the maker’s page handy for your model to confirm part numbers. Also keep a guide that shows safe valve shut-off steps, in case a family member must turn water off while you fetch a tool.
Sustainability Angle And Disposal
A small seal or insert saves a full mixer from landfill and cuts water waste. Bag old parts so shards don’t scratch the sink. If the cartridge has metal, send it to scrap. Rubber and mixed parts go to general waste unless your council offers a special stream. Wipe up drips so the cupboard base stays dry.
What If The Drip Returns?
Recheck that the part is seated and the retaining ring is snug. Look inside the body with a torch to see if the seat has a groove. If yes, a seat insert kit can rescue it. If the leak sits at the spout joint, the O-rings at the base need replacing.
Ready-To-Use Mini Plan
- Identify tap style
- Buy exact matching parts
- Isolate water and drain the mixer
- Strip handle and trim
- Swap seal or cartridge
- Clean, rebuild, and test