Dripping Tap: How to Fix It and When to Call a Plumber

A dripping tap is easy to ignore. It is just a drop every few seconds, after all. But left unattended, a single dripping tap can waste more than 5,000 litres of water a year — and if it is a hot tap, you are paying to heat every one of those litres too. The good news is that the fix is often straightforward, and many homeowners in the TW area can tackle it themselves with basic tools.

Why Is My Tap Dripping?

Most taps drip for one of two reasons:

• A worn washer — found in traditional pillar taps (the older style with separate hot and cold handles). The rubber washer sits at the base of the headgear and presses against a valve seat to stop the flow. Over time it hardens, cracks, or deforms, and water seeps past.
• A worn or damaged cartridge — found in modern mixer taps and ceramic disc taps. The cartridge controls both flow and temperature. When it fails, the tap drips or becomes stiff.

Knowing which type of tap you have tells you which repair you need.

What You Will Need

For a washer replacement:

• Adjustable spanner or basin wrench
• Flathead and Phillips screwdrivers
• Replacement washers (a mixed pack costs very little from any hardware shop)
• PTFE tape
• A cloth or small towel

For a cartridge replacement, you will also need the correct cartridge for your tap brand and model. Take a photo of your tap before you go shopping, or remove the old cartridge and take it with you.

Step-by-Step: Replacing a Tap Washer

1. Turn Off the Water Supply

Locate the isolation valve on the supply pipe under the sink and turn it a quarter-turn with a flathead screwdriver so the slot is across the pipe. If there is no isolation valve, turn off the mains stopcock — usually under the kitchen sink or where the supply enters the property.

Open the tap to release any remaining pressure and drain the line.

2. Remove the Tap Handle

Prise off the decorative cap on top of the handle (it usually pops off with a flathead screwdriver). Undo the screw underneath and lift the handle away.

3. Unscrew the Headgear

Use your spanner to unscrew the headgear (the large nut beneath the handle). Turn anticlockwise. Lift the headgear out carefully.

4. Replace the Washer

You will see the old washer held in place by a small nut at the base of the headgear. Undo the nut, remove the old washer, and press the new one into place. Refit the nut firmly.

5. Reassemble and Test

Screw the headgear back in, refit the handle, and slowly restore the water supply. Turn the tap on and off a couple of times and check for drips.

Step-by-Step: Replacing a Cartridge

The process is similar up to step 3. Once the handle is off, you will see the cartridge held by a retaining nut or clip. Remove it, pull the cartridge straight out, and fit the new one in the same orientation. Reassemble and test.

Some ceramic disc cartridges can simply be cleaned rather than replaced — mineral deposits from hard water (very common across the TW area) can cause sticking and dripping without the disc itself being damaged.

How Much Water Does a Dripping Tap Waste?

To put the numbers in perspective:

• A tap dripping once per second wastes roughly 15 litres per hour
• That is around 360 litres per day
• Over a year, more than 130,000 litres — for a fast drip

Even a slow drip adds up. Thames Water’s own guidance highlights dripping taps as one of the most common sources of household water waste in the region.

When to Call a Plumber Instead

DIY tap repair is perfectly reasonable in many situations, but call a professional if:

• You cannot isolate the water supply — no isolation valve and you are unsure where the stopcock is
• The tap seat is damaged — if the brass seat the washer presses against is pitted or corroded, a new washer will not seal properly; the seat needs re-grinding or the tap needs replacing
• Water is leaking from the body of the tap — not just the spout, but from the base or the spindle; this suggests a more serious seal failure
• The drip returns quickly after repair — a sign the seat is damaged or the cartridge was not the root cause
• You have a mixer tap under pressure and are not confident — pressurised systems can cause a significant leak if reassembled incorrectly
• The leak is getting worse or you can see water damage — damp under a sink can lead to mould and structural damage if left

Reassurance

A dripping tap is rarely an emergency on its own, but it is worth sorting promptly to protect your water bill and your pipework. If you have followed the steps above and the drip continues, or if you have discovered water damage under the sink or around the tap base, do not leave it any longer.

Our team covers the TW postcode area around the clock. Call us on 07725 479493 any time and we will send someone out to take a look.