A dripping laundry tap in Casula had been going so long the owner had stopped hearing it. She only rang because her tenant's water bill had jumped and she wanted a water efficiency certificate. I changed two washers and a body washer, and the drip had probably cost her more in water over the year than the visit did. That is a leaking tap in a nutshell: cheap to fix, expensive to ignore, and about half of them you can fix yourself.
This post shows you how to fix a leaking tap with a standard washer, how to tell when the problem is the O-ring, the seat or a mixer cartridge instead, what a plumber charges for it in South West Sydney, and where the line sits between a Saturday morning job and a licensed one. If you would rather not, we are a toilet and tap plumber, no call-out fee, across South West Sydney.
On a standard two-handle tap, a drip from the spout is a worn washer: turn off the water at the meter, undo the spindle, swap the jumper valve and the O-ring, and reassemble without over-tightening. A homeowner can legally do that in NSW. If it still drips the seat needs recutting, and a leaking mixer tap needs a brand specific cartridge, so both are plumber jobs.
First, which kind of tap have you got?
Almost every tap in a Sydney house is one of two designs. A standard tap (a jumper valve tap) has separate hot and cold handles that turn several times. Inside is a spindle that screws down onto a rubber washer, which presses onto a brass seat to stop the water. A mixer tap has one lever that lifts and swings. Inside is a ceramic disc cartridge, and there is no washer at all. The fix is completely different for each, so work out which you have before you buy anything.
Where is it leaking from? That tells you the part
Leak location is the diagnosis. A drip from the spout when the tap is off is the washer on a standard tap or the cartridge on a mixer. Water coming out around the handle when the tap is on is the O-ring or body washer on a standard tap, or the cartridge seals on a mixer. A tap that needs cranking hard to stop the drip has a worn seat: the washer is being crushed against a pitted surface and will never seal until the seat is recut. A tap that squeals or bangs when it shuts is the washer or a loose spindle, and if the pipes bang, read my post on water hammer. Water under the basin has nothing to do with the tap. It is the flexi hoses or the waste, and the flexi hose check is where to start.
| Symptom | Likely cause | Fix | DIY or plumber |
|---|---|---|---|
| Drips from the spout when off (standard tap) | Worn washer, sometimes the seat | New jumper valve; reseat if pitted | DIY for the washer |
| Drips from the spout when off (mixer) | Worn ceramic cartridge | New cartridge, brand specific | Plumber |
| Leaks around the handle when on | Spindle O-ring or body washer | Replace both | DIY if the spindle comes out cleanly |
| Hard to turn, still drips | Pitted seat, dry spindle | Reseat, grease, new washer | Plumber |
| Squeal or bang on shut-off | Washer or loose spindle | New washer, service the spindle | DIY unless the pipes bang |
| Water under the basin | Flexi hose, isolation valve or waste | Depends on the source | Plumber |
How to fix a leaking tap: tap washer replacement step by step
You need a shifting spanner, a flat screwdriver, a rag, and the right washer. Standard basin, sink and shower taps in Australia take a 15 mm (half inch) jumper valve; laundry and garden taps usually take 20 mm (three quarter inch). A jumper valve with the washer already fitted saves fiddling. Buy a couple of body washers and O-rings in the same trip.
- Turn the water off at the meter, or at the isolation valve under the basin if there is one. Open the tap to drain the pressure, and put the plug in so small parts do not go down the drain.
- Take off the handle. Most have a button or cap on top hiding a screw. Lift the flange or cover underneath to expose the spindle nut.
- Undo the spindle with the shifter, anticlockwise, and lift it out. Wrap the rag around chrome parts so you do not scratch them.
- Pull out the old jumper valve. It sits loose in the body or on the end of the spindle. Match the new one to it.
- Look at the seat inside the tap body with a torch. Smooth and shiny is good. Pitted, rough or ringed means it needs reseating, and the new washer will only be a temporary fix.
- While the spindle is out, swap the body washer (the ring under the spindle nut) and the O-ring on the shaft, and smear a little tap grease on the thread.
- Drop in the new jumper valve, refit the spindle and nip it up firmly, not viciously. Refit the flange and handle.
- Turn the water back on slowly, open the tap gently, then close it and watch the spout for a minute.
Fifteen minutes the first time, five after that. The mistakes I see are over-tightening (which crushes the new washer and strips the thread), the wrong size jumper valve, and ignoring a pitted seat. If it still drips after a new washer, the seat is the problem. A reseating tool grinds it flat again, and that is where I would hand it over: the tool is not worth buying for one tap, and it is easy to wreck the body.
Mixer tap leaking: the cartridge
A leaking mixer tap is nearly always the ceramic disc cartridge. Grit from the mains scores the discs, the rubber seals under them perish, and the lever gets stiff or the spout drips. The cartridge is a replaceable unit, but it is brand specific: a Methven, Caroma, Phoenix or Dorf cartridge will not swap between brands, the cheap imported mixers often have no spare available at all, and the retaining nut is usually seized by the time it leaks. When there is no cartridge to be had, the tap gets replaced, and I would rather tell you that on the phone than after an hour under your sink.
The rule of thumb in NSW is that a homeowner can change a tap washer; Sydney Water says as much on its own plumbing information page. Anything more involved on the tap, and anything on the pipework and connections behind it, is licensed plumbing work. The cartridge sits on the wrong side of that line for me, and a new mixer certainly does, so leave both to a plumber.
Leaking tap cost in Sydney
The Sydney 2026 price guides put a leaking tap repair at $92 to $300. The bottom of that range is a washer and reseat on one tap in business hours; the top is a mixer cartridge that has to be ordered, or an after-hours visit. New tapware, and any job where the tap has to be replaced, is quoted on inspection, because the price is mostly the tap you choose. The way to get value is to do every dripping tap in the house in one visit. The call-out is the same, the second and third taps are quick, and I check the isolation valves and flexi hoses under each one while I am there. A dripping tap is never an emergency. If it is driving you mad at 9 pm, turn off the isolation valve under the basin and ring in the morning.
Why a dripping tap matters more for landlords
If you own a rental in Fairfield or Liverpool, a leaking tap is not just a water bill. In NSW you can only charge tenants for water usage if the property meets the water efficiency measures, and one of those is no leaking taps or toilets at the start of the tenancy and whenever the measures are checked. A water efficiency certificate visit is mostly fixing drips, checking flow rates and testing the cisterns, and a running toilet is the other thing that fails it.
When to call a plumber
Call when a new washer has not stopped the drip, when the spindle will not come out or the tap is corroded, when it is a mixer tap, when the tap needs replacing, or when the leak is under the basin rather than at the tap. Call sooner if the tap will not turn off at all: shut the isolation valve or the meter and that becomes a same-day job rather than an after-hours one.
Done right. Done once. Monarch covers South West Sydney and the Macarthur region for taps, toilets and fixtures, from a single washer to full tapware on a renovation. If you need a plumber in Casula or the surrounding suburbs, ring 0455 222 292 and I will price it before I start.
Related guides: water hammer.
Need it sorted? Ring 0455 222 292 any hour or book online. Monarch Civil & Plumbing is a toilet and tap plumber, no call-out fee: fixed properly in one visit, quoted before we start.
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Frequently asked
Why does my tap keep dripping after I changed the washer?
Almost always the seat. The brass seat inside the tap body gets pitted and ringed over the years, and a new washer cannot seal against a rough surface no matter how hard you turn the handle. It needs recutting with a reseating tool, which takes a plumber a few minutes. The other causes are the wrong size jumper valve, a washer crushed by over tightening, or a cracked tap body on an old tap.
Can I legally change a tap washer myself in NSW?
Yes. Plumbing work in NSW has to be done by a licensed plumber, but minor maintenance like changing a tap washer is accepted as something a homeowner can do, and Sydney Water says so on its own plumbing information page. Replacing a tap, working on the flexi hoses and connections under the basin, or altering pipework is licensed work. Turn the water off at the meter first and do not over tighten anything.
How much does it cost to fix a leaking tap in Sydney?
The Sydney 2026 price guides put a leaking tap repair at $92 to $300. A washer and reseat on one tap sits at the bottom of that range; a mixer cartridge that has to be ordered sits at the top. Replacing the tap itself is quoted on inspection because the tapware is most of the price. Having every dripping tap done in one visit is the cheapest way per tap.
How do I fix a leaking mixer tap cartridge?
The ceramic disc cartridge inside the mixer is replaced as a unit, but it has to be the exact cartridge for that brand and model, and the retaining nut is usually seized by the time the tap leaks. Cheap imported mixers often have no spare available, in which case the tap is replaced. In NSW it sits beyond the tap washer that a homeowner is allowed to change, so book a plumber and tell them the brand when you ring.
How much water does a dripping tap waste?
A tap dripping about once a second loses somewhere around twenty litres a day, which adds up to thousands of litres a year on your water bill for nothing. Faster drips and a tap that runs in a thin stream waste far more. For a landlord it also matters for the water efficiency rules: a property with a leaking tap does not meet them, so you cannot pass water usage charges on to the tenant until it is fixed.
Should I repair a leaking tap or replace it?
Repair it if the body is sound and the parts are available: a washer, seat or cartridge is a fraction of the cost of new tapware. Replace it when the chrome is pitted through, the body is cracked, the spindle is seized in the body, or it is a cheap mixer with no cartridge available. If you are already planning a vanity or kitchen update, put the money into the new tap rather than the old one.
Licensed plumber and drainer based in Austral, 13+ years in the trade, working across Liverpool, Fairfield and the Macarthur region. About Paul