Leaking tap: 5 causes and what you can fix yourself

A ticking tap weighs on the mind — and on the water bill. A one-drop-per-second leak adds up to around 11,000 litres a year disappearing down the sink. The good news: half the time you can fix it yourself with a set of Allen keys and a trip to the hardware store.

The five most common causes

Domestic taps almost always come down to the same shortlist. Not all of them are equally serious: a worn O-ring is a five-minute job, a cracked ceramic cartridge needs a bit more work.

• Worn O-ring or washer — the most common on older mixer taps, the rubber hardens and leaks.
• Damaged ceramic cartridge — on single-lever taps, recognised by stiff turning AND a leak.
• Limescale on the seats — typical with hard water (greater Waregem sits around 35° fH), the disc no longer closes perfectly.
• Water pressure too high — above 4 bar taps fail faster; measure with a gauge on an outdoor tap.
• Misfitted or worn flexible hose — the soft connector under the basin is a classic on older installations.

What you can swap yourself

O-rings and washers are standard parts, available in any DIY store. Close the main valve first (or the stopcock under the basin), open the tap to release pressure, remove the handle and headworks and swap the rubber. A good tip: change every O-ring at once, not just the leaking one — the others are the same age.

When to call a plumber

Leak isn't at the tap but under the basin or inside the wall? Stop tinkering. A hidden leak between tiles or in the screed can damage the structure within weeks and is hard to locate without a thermal camera. Same for a humming or whistling tap: that usually points to pressure or pipe issues, not the tap.

Not sure? Send us a photo by WhatsApp. We have a look and tell you honestly whether it is a DIY job or not.