A tap dripping once per second wastes around 5,500 litres of water per year. That's both an environmental and a cost issue — and in most cases, it's fixable.
Here's what causes a dripping tap and what to do about it.
Why is my tap dripping?
Worn washer (most common cause)
Traditional taps — the kind with separate hot and cold — use a rubber washer that presses against a valve seat to stop water flow. Over time, the washer wears down or hardens and no longer creates a proper seal.
The drip usually comes from the spout and gets worse over time as the worn washer damages the seat itself.
Fix: Replace the washer. It's one of the more straightforward plumbing jobs and requires turning off the water supply, removing the tap head, and replacing the washer and O-ring. If you're comfortable with basic DIY, this is doable. If not, it's a short job for a plumber.
Worn O-ring (dripping from the base)
If the drip is coming from around the handle or base of the tap rather than the spout, it's usually the O-ring — a small rubber ring around the stem of the tap.
Fix: Same process as a washer replacement — turn off water, remove the tap head, replace the O-ring.
Cartridge fault (mixer taps)
Modern mixer taps use a ceramic cartridge rather than a washer. These are more durable but do eventually fail — usually leaking from the spout when the tap is off.
Fix: The cartridge needs replacing. It's more straightforward than it sounds — the cartridge pulls out and a new one slots in — but getting the right replacement cartridge for your specific tap model matters.
Damaged valve seat
If a worn washer has been left for a long time, it can score and damage the brass valve seat it presses against. At that point, replacing the washer alone won't fix the drip.
Fix: The seat needs to be reground (using a valve seat grinder) or replaced. This is a job for a plumber.
Can I fix it myself?
For a washer or O-ring replacement on a traditional tap — yes, if you're comfortable with DIY and know how to isolate the water supply. The parts cost under £5.
For cartridge replacements or any damage to the valve seat, it's worth calling a plumber. Getting it wrong means a bigger leak, not just a drip.
How urgent is it?
It depends on how bad it is. A slow drip can wait a few days. But:
- If the drip is getting faster, deal with it soon — it won't stop on its own
- If there's water around the base of the tap, check under the sink for signs of a bigger leak
- If the tap is in a rented property, report it to your landlord — you're not responsible for the repair
If you've got a dripping tap in Hemel Hempstead, Ealing, or NW London and want it sorted properly — get in touch. We'll tell you upfront what the job involves and what it costs.