A tap that drips once every few seconds can be easy to ignore, especially when the rest of the plumbing seems fine. But knowing how to fix a leaking tap can save water, prevent damage around the basin or benchtop, and stop a small worn part becoming a more involved repair.
The right fix depends on where the water is coming from. A drip from the spout usually points to an internal washer, ceramic cartridge or valve issue. Water around the handle, under the sink, or at the base of the tap can have a different cause altogether. Before pulling the tap apart, take a moment to identify the leak and decide whether it is a sensible DIY job or one best handled by a licensed plumber.
First, work out where the tap is leaking
Turn the tap fully off and dry it with a cloth. Watch closely for a minute or two. If water forms at the end of the spout, the seal inside the tap is no longer closing properly. This is the most common type of leaking tap.
If water appears around the handle when the tap is on, the problem may be an O-ring, packing seal or cartridge. A leak at the base of a mixer tap can mean a worn seal, loose retaining nut or water getting beneath the tap body. Water in the vanity cabinet often comes from the flexible hoses, isolation valves or waste pipe rather than the tap itself.
This distinction matters. Replacing a washer will not fix a split flexi hose, and tightening a handle will not repair a cracked tap body.
How to fix a leaking tap from the spout
For a traditional separate hot and cold tap, the usual cause is a worn jumper valve washer. For a quarter-turn or mixer tap, it is more likely to be a ceramic cartridge. Both are serviceable in many cases, but the process and replacement parts differ.
Before starting, turn off the water supply. Look under the sink for the small isolation valves on the hot and cold supply lines. Turn them clockwise until closed, then open the tap to confirm the water has stopped. If there are no working isolation valves, you may need to shut off the main water supply to the property.
Put the plug in the basin before removing anything. Small screws, clips and washers have a habit of disappearing down the waste.
Repairing a conventional washer tap
Remove the cap on top of the handle, which may simply pry off with a small flat screwdriver. Undo the screw beneath it and lift off the handle. Next, use a spanner to remove the cover and expose the tap spindle.
Unscrew the spindle carefully. At its base, you should find the jumper valve and rubber washer. If the washer is split, flattened, hard or visibly worn, replace it with a matching washer. It is worth taking the old part to a plumbing supplier if you are unsure of the size.
Check the brass valve seat inside the tap body while the spindle is out. A rough, pitted or damaged seat can quickly ruin a new washer and keep the tap dripping. In that case, fitting a washer alone is unlikely to be a lasting repair. The seat may need resurfacing or the tap may need replacement.
Reassemble the tap in reverse order. Do not overtighten the spindle or handle screws. Turn the isolation valve back on slowly, run the tap and check for a clean shut-off.
Repairing a mixer or quarter-turn tap
Mixer and quarter-turn taps use a cartridge rather than a simple rubber washer. Start by removing the handle, often secured by a small grub screw hidden beneath a cap or at the rear of the lever. An Allen key is commonly required.
Once the handle and decorative cover are off, remove the retaining nut or clip that holds the cartridge in place. Lift the cartridge out and take note of its orientation before installing the replacement. Cartridges can look similar while having different spline counts, pin positions and sizes, so an exact match is essential.
Clean away any scale or debris in the tap body, fit the new cartridge, and reassemble the tap. Switch the water back on gently and test both hot and cold functions. If the handle feels stiff, the flow is poor, or the leak remains, stop forcing it. The cartridge may be incorrect, the tap body may be damaged, or the issue may be deeper in the valve assembly.
Do not overlook leaks around the handle or base
A handle leak often appears only while the tap is running. On an older spindle tap, replacing the O-ring on the spindle may solve it. On a mixer, the cartridge seals or O-rings may be worn. Silicone grease approved for plumbing seals can help during reassembly, but petroleum-based products should be avoided because they can damage rubber components.
A leak around the base of a kitchen mixer is different again. The tap may need to be removed from beneath the sink so its base seals and mounting hardware can be inspected. Access can be tight, particularly in older cupboards, and seized nuts or corroded parts can turn a quick repair into a frustrating job.
If moisture has been present under the sink for some time, check the cabinet base for swelling or mould. Dry the area thoroughly after the repair and monitor it over the next few days. Catching a slow leak early is far cheaper than replacing damaged cabinetry.
When a leaking tap is not a DIY repair
There is no benefit in pushing on with a repair when the likely outcome is a damaged fitting, water leak or costly replacement. Call a plumber if the isolation valves will not shut off, the tap is badly corroded, a pipe or flexi hose is leaking, or the tap has cracked.
It is also sensible to get help if you cannot identify the correct cartridge, the valve seat is damaged, or the leak returns immediately after fitting a new washer. Repeatedly tightening a tap to stop it dripping can damage the internal mechanism and make the repair more involved.
For rental properties, landlords and property managers should consider whether a DIY repair is appropriate under their maintenance process. A clear record of the fault, the parts used and the completed repair is useful, particularly where a recurring leak has affected cabinetry or flooring.
A few checks that prevent the next leak
Taps wear out over time, but excessive force makes that happen faster. Turn traditional taps off firmly rather than cranking them tight. If a tap needs extra force to stop dripping, it is already asking for attention.
Hard water deposits can also affect moving parts and aerators. Cleaning the aerator at the end of the spout can improve flow, although it will not usually stop a drip from the tap itself. If the tap is old, loose, corroded or difficult to operate, replacement can be better value than repeated repairs.
A plumber can assess whether the existing tap is worth servicing or whether a new tap is the more reliable option. For Scarborough and nearby Perth suburbs, Streamline Plumbing & Drainage can inspect the issue, explain the repair options and provide a fixed-price quote before work begins. No hidden costs and no work proceeding without your approval.
A leaking tap rarely fixes itself, but it also does not need to become a major plumbing problem. Start by locating the leak, isolate the water, and replace only the part you can confidently identify. If the repair is unclear or the leak involves pipes, valves or damaged fittings, arranging a professional repair gives you a lasting fix and certainty about the cost.