How to Stop a Dripping Tap and When to Call a Plumber

Traditional taps: worn washers

Older-style taps with separate hot and cold handles usually rely on a rubber washer that seals against the valve seat. Over time this washer wears down or hardens, allowing water to seep past even when the tap is fully closed. Replacing the washer is a well-known DIY job, provided you turn off the water supply first.

Mixer taps: worn cartridges

Modern mixer taps typically use a ceramic disc cartridge rather than a washer. These are generally more durable but can still wear out or get damaged by grit in the water supply, causing a drip. Cartridges are usually specific to the tap model, so it's worth identifying the make before ordering a replacement.

Steps before attempting a repair

• Turn off the water supply to the tap, either at an isolation valve or the main stopcock
• Open the tap to release remaining pressure and drain residual water
• Protect the plughole so small parts can't fall down the drain
• Note how the tap comes apart, or take photos as you go, to make reassembly easier

When it's worth calling a plumber instead

• The tap is old and parts are difficult to source
• You've replaced the washer or cartridge and the drip continues
• The tap is stiff, damaged, or the spout itself is leaking rather than the handle
• You're not confident isolating the water supply safely

Is it worth repairing an old tap at all?

For a tap that's otherwise in good condition, a washer or cartridge replacement is usually the most cost-effective fix. For a tap that's old, scaled up internally, or already had multiple repairs, replacement may end up being the more sensible long-term option.

What if the drip is coming from the flexible connector, not the tap?

Occasionally what looks like a leaking tap is actually water tracking down from a worn flexible tap connector underneath the basin or sink, where the pipework meets the isolation valve. These connectors have a limited lifespan and their rubber seals can perish, particularly in an airing cupboard or under-sink cabinet that gets warm. If you spot damp inside the cupboard but the tap itself seems dry when running, it's worth checking the connector before assuming the tap needs stripping down.

How an engineer approaches a persistent drip

When a call-out is booked for a dripping tap, an engineer will usually isolate the supply first, then check whether the issue is the washer, the cartridge, the valve seat itself, or a connector further back in the pipework. On older taps, a worn or pitted valve seat can stop even a brand-new washer sealing properly, in which case reseating the valve or fitting a seat-liner may be needed rather than simply swapping the washer again.

• Isolate the water supply and confirm which tap and outlet is affected
• Strip the tap head down to inspect the washer, O-ring or cartridge
• Check the condition of the valve seat for pitting or scale damage
• Check flexible connectors and isolation valves under the sink for separate leaks

Preventing repeat drips

Once a tap has been repaired, a few simple habits help it last longer. Avoid over-tightening the handle to stop a drip, since this accelerates wear on the washer or cartridge seat rather than solving the underlying problem. In hard water areas, an occasional descale of the tap outlet and aerator also reduces the grit and scale that can damage cartridges prematurely.