Guides
How to fix a leaking tap (and when to call a plumber)
To fix a leaking tap, turn off the water at the meter, remove the tap handle and bonnet, and replace the jumper valve washer and O-ring. Reseating the tap body fixes drips a new washer will not stop. Ceramic disc and mixer taps need cartridge replacement, which is usually a job for a plumber.
Most dripping taps come down to a worn washer, and swapping a tap washer is one of the very few plumbing jobs a NSW homeowner is allowed to do without a licence. Done carefully with the water off, it is a twenty minute job and a two dollar part. Done carelessly, it is a stripped spindle and a flooded vanity.
Know your tap before you start
Traditional taps that turn two or three times from off to full use a jumper valve and washer, and they are the DIY-friendly kind. Quarter-turn taps contain ceramic disc cartridges and have no washer at all. Single-lever mixers also run on cartridges. If your tap moves less than a full turn from closed to open, skip ahead to the last section, because a washer swap is not the repair it needs.
Step 1: turn the water off
Shut the stop valve at the water meter, then open the leaking tap fully to drain the line and confirm the water really is off. Mixers and some newer basins have mini isolation stops under the bench, but standard wall and pillar taps almost never do, so the meter is your isolation point.
Step 2: strip the tap
Pop the button or cover off the handle, undo the retaining screw and lift the handle away. Remove the flange, then undo the bonnet with a spanner, protecting the chrome with a cloth. The spindle assembly lifts out, and sitting at the bottom of the tap body you will find the jumper valve with its washer.
Step 3: replace the washers
Fit a new jumper valve washer, and while everything is apart replace the body washer and the O-ring on the spindle too, because those are the parts that cause leaks around the handle later. A smear of tap lubricant on the spindle threads makes an old tap feel new. Reassemble, turn the water back on slowly and test.
Still dripping? The seat is worn
When a brand new washer will not stop the drip, the brass seat inside the tap body is pitted, and no washer can seal against a rough seat. The fix is reseating: a small cutting tool grinds the seat flat again so the washer has a clean surface to close onto. It is the step most DIY repairs miss, and it is the difference between a tap fixed for a decade and a tap dripping again by spring.
Where DIY ends
Mixer and ceramic disc cartridges are model-specific, easy to damage and often hide seized isolation valves behind them. Shower and bath wall taps that refuse to seal can have cracked bodies or breech problems, and a mistake there leaks inside the wall where it stays invisible until the plaster stains. Corroded spindles that will not budge tend to round off fast under force. And anything beyond a washer swap, replacing a tap, relocating one, or repairing pipework, is licensed work in NSW. Terry has held NSW plumbing licence L10959 across nearly four decades of tap rebuilds since 1986, and reseating is part of every tap repair he does rather than an optional extra.
A tap never heals on its own. Each day of dripping carves the seat a little deeper, so the earlier the washer goes in, the longer the tap lasts. Change it at the first drip and the job stays a twenty minute one.
Frequently asked questions
- Is it legal to change a tap washer yourself in NSW?
- Yes. Replacing a tap washer is one of the few plumbing tasks a NSW homeowner may do without a licence. Almost everything else, including replacing the tap itself or working on pipework, must be done by a licensed plumber.
- Why does my tap still drip after a new washer?
- The brass seat inside the tap body is worn or pitted, so even a perfect washer cannot seal against it. The tap needs reseating with a seat-cutting tool, which grinds the surface flat again. Skipping this step is the most common reason DIY repairs fail.
- What size washer do household taps take?
- Most standard Australian household taps take a 12 mm jumper valve washer, but sizes and styles vary with age and brand. The safest approach is to take the old jumper valve to the hardware store and match it directly.
- Can I fix a dripping mixer tap myself?
- It is rarely worth the risk. Mixers use model-specific ceramic cartridges, the seals damage easily, and the isolation valves behind them are often seized. Getting the wrong cartridge or nicking an O-ring means a second leak, so most people hand mixers to a plumber.
- Do I turn the water off at the meter or under the sink?
- For standard wall and pillar taps, at the meter, since they rarely have their own isolation valves. Mixers often have mini stop taps on their flexible hoses under the bench, which lets you isolate just that fixture.
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Terry's been sorting plumbing across Berala and Western Sydney since 1986. Call 0415 274 542 for a straight answer and a fixed price.
NSW Licence L10959 · 40+ years experience