How to Fix a Leaking Tap: DIY Guide and When to Call a Plumber
24 May 2026 · Plumbers On Duty
Quick answer
A standard dripping tap is almost always a worn washer or O-ring. Replacing it takes 20 minutes and costs under R50 in parts. Mixer taps (single-lever) use a cartridge instead, which is also a DIY fix but slightly more involved.
If the leak is from the wall, under the basin, or you cannot shut off the water, call a plumber — water damage costs far more than a callout.
What you need
- New tap washer (10mm or 12mm — bring the old one to the hardware shop)
- Adjustable spanner or shifter
- Flathead screwdriver
- Cloth (to protect chrome)
Step-by-step: fix a dripping compression tap
- Turn off the water. Use the isolation valve under the basin if there is one, otherwise turn off the main at the meter.
- Open the tap to drain remaining water.
- Remove the tap handle. There is usually a screw hidden under the hot/cold indicator cap — pop the cap off with a screwdriver.
- Unscrew the headgear (the brass body under the handle) with a spanner. Hold the tap spout with a cloth so you do not scratch it.
- Replace the washer at the bottom of the headgear. While you are there, check the O-ring on the spindle and replace if perished.
- Reassemble in reverse order. Do not over-tighten — finger-tight plus a quarter turn is enough.
- Turn the water back on slowly and check for leaks.
How to fix a leaking mixer tap
Mixer taps use a ceramic cartridge. To replace it:
- Turn off the water and remove the lever (small grub screw on the side or under a coloured cap)
- Unscrew the chrome cap and lift out the cartridge
- Take it to your hardware shop and match it exactly — there are dozens of variations
- Drop the new cartridge in, reassemble, test
If you cannot find a matching cartridge, that is your sign to call a plumber.
When to call a plumber instead
DIY is not the right call for:
- Leaks from the wall behind the tap — that is a pipe leak, not a tap leak
- Leaks from under the basin — could be the trap, supply line, or shutoff valve
- You cannot turn off the water — old isolation valves often seize; a plumber can replace them
- The tap body is corroded — the whole tap needs replacing
- You stripped a thread trying to remove a stuck part
- It is a geyser overflow dripping outside — that means the geyser pressure valve has failed (urgent)
A standard call-out and tap fix runs R450–R900 in most SA cities. Geyser-related leaks are more urgent and more expensive.
Why a dripping tap matters
A tap dripping once per second wastes about 15 litres a day — over 5,000 litres a year. In water-restricted municipalities (Cape Town, parts of Gauteng, Eastern Cape) that is money straight out of your pocket, plus the risk of a small leak becoming a big one.