A dripping tap wastes more water than most people realise and can cost you money on your water bill. Here's what causes it, what's involved in fixing it, and when it's worth calling a professional.
Why a Dripping Tap Is Worth Fixing Quickly
A tap that drips once per second wastes over 30 litres of water a day — more than 10,000 litres a year. Beyond the environmental cost, if you're on a water meter that's money going straight down the drain. A dripping hot water tap also wastes the energy used to heat that water. The good news is that most dripping taps are caused by worn internal parts that are inexpensive to replace.
What Causes a Tap to Drip?
The most common cause is a worn tap washer — a small rubber disc inside the tap body that presses against a valve seat to stop water flow. Over time the washer hardens, cracks or wears away and can no longer form a watertight seal. On newer ceramic disc taps, a cracked or worn ceramic cartridge is usually the culprit. Other causes include a damaged valve seat, worn O-rings around the cartridge or spindle, or high water pressure forcing water past worn components.
Traditional Taps vs Ceramic Disc Taps
Traditional pillar taps use a rubber washer on a threaded spindle. They require multiple turns to open and close and the washer is straightforward to replace. Ceramic disc taps use a ceramic cartridge and only require a quarter turn to operate. They are generally more durable but when they do fail the entire cartridge usually needs replacing. Knowing which type you have helps you buy the right replacement part before starting the job.
Replacing a Tap Washer: What's Involved
The water supply to the tap must first be isolated — either at the isolating valve beneath the sink or at the main stopcock. The tap handle and headgear are then removed to access the washer, which is unscrewed and replaced. The tap is reassembled and the water turned back on to check the repair. The parts cost pennies. The job typically takes 30–60 minutes for someone familiar with it, but can take longer if the tap is old, corroded or in an awkward location.
When to Call a Plumber
Call a professional if you cannot locate or operate the isolating valve, if the tap is corroded and parts are seized, if the drip is coming from the base of the tap rather than the spout (indicating a worn O-ring or a more involved repair), or if you replace the washer and the tap still drips. A plumber will also advise whether an old tap is worth repairing or whether replacement is the better long-term option.
What Does a Dripping Tap Repair Cost?
In the Hertfordshire area, a plumber call-out to repair a dripping tap typically starts from £75, covering the visit and a washer or cartridge replacement on a standard tap. If the valve seat is damaged or the tap needs replacing, expect to pay more for parts and additional labour. Getting it fixed promptly is almost always cheaper than leaving it.