Why Your Tap Drips After Shutting Off the Water & How to Fix It Yourself

Why You Should Fix a Dripping Tap Immediately

A dripping tap isn't just an annoying sound – it's a real financial cost and, in the long term, a risk of greater damage.

Even one drip per second means several hundred litres of wasted water over a year, directly impacting your water bill. If the water is hot, you pay double – for both the water and its heating.

• Constant moisture around the sink promotes the growth of mould and rust stains on the basin and bathroom surfaces.
• A worn washer or cartridge can leak more severely over time, causing water to collect inside cabinets or partition walls.
• Continuous dripping accelerates further wear of the internal cartridge components, as moving parts never get to fully rest.

Cartridge Mixer Tap vs. Two-Handle Tap – Different Causes

Before starting repairs, it's worth identifying the type of tap you have, as the internal construction and therefore the repair method differ significantly.

Ceramic Cartridge – The Most Common Cause of Dripping

A ceramic cartridge consists of two tightly ground discs that move against each other when the lever is operated, opening or closing the water path. If the discs are perfectly smooth and clean, the cartridge completely seals the water and prevents a single drip.

Over time, however, the discs can wear, scratch, or fail to press together completely due to limescale and dirt – in which case, a microscopic gap always remains, allowing water to drip through even when the lever is fully closed.

The lifespan of a cartridge largely depends on water quality – in areas with hard, lime-rich water, the cartridge wears out many times faster than in areas with soft water, as limescale crystals act like fine sandpaper, scratching the ceramics with each use.

• The average lifespan of a ceramic cartridge is 5–10 years, but in hard water areas, it can be as short as 2–4 years.
• The cartridge is usually a replaceable part, which you don't need to order separately from the tap body – most manufacturers sell only the cartridge as a spare part.
• When replacing a cartridge, it is crucial to choose the exact size and model, as cartridges are not universal.

Rubber Washers and O-Rings

In addition to the cartridge or valve spindle, a tap uses several smaller rubber washers and O-rings that seal connections and keep water flowing in the desired direction.

If these seals age, harden, or crack, they no longer press tightly enough against the metal or ceramic surface, which can cause dripping not only directly from the spout but also from under the tap body or around the lever.

Limescale and Dirt – A Silent but Significant Cause

In many regions of Estonia, especially in Harjumaa and other areas with lime-rich groundwater layers, tap water is quite hard, meaning it contains abundant calcium and magnesium salts. These salts gradually deposit wherever water flows and slowly evaporates or stands – including between the cartridge discs and on the surface of washers.

A layer of limescale may not be immediately visible to the naked eye, but even a thin film prevents the cartridge discs from fully compressing, leaving a small gap through which water drips.

The good news is that dripping caused by limescale can often be resolved without replacing a spare part – simply remove the cartridge or washer and clean it thoroughly in a vinegar or descaler solution.

• Soak the cartridge or washer in a diluted vinegar solution for 20–30 minutes to soften the limescale.
• Use a soft brush (such as an old toothbrush) to remove visible deposits from between the discs and edges.
• Rinse the part thoroughly with clean water before reassembling it into the tap.
• If limescale has already caused deep scratches to the ceramic, cleaning will no longer help, and the cartridge must be replaced.

Excessively High Water Pressure as a Cause of Dripping

While most dripping incidents result from worn parts, the cause can also be excessively high water pressure in the house or apartment. If the pressure in the piping is higher than usual, the cartridge or washer must be able to shut off the water flow with greater force, and even minimal wear, which would not cause dripping at normal pressure, will start to leak at higher pressure.

High water pressure can be related to the general plumbing setup of the building, a central pressure pump in an apartment block, or a fault in the boiler. If you notice that several taps in the house are dripping simultaneously or water flows from the tap with an unusually strong jet, it's worth checking the overall water pressure – we have written more extensively on the topic of apartment water pressure in a dedicated article.

Incorrect Installation or Improperly Assembled Cartridge

Sometimes, the reason for dripping isn't wear, but simply that the cartridge or washer hasn't been installed correctly. If a spare part was inserted the wrong way during a previous repair, slightly askew, or not fully seated in its housing, it may not seal properly even when brand new.

Similarly, a problem can arise if the cartridge retaining nut is not tightened sufficiently – in this case, the cartridge will not press its internal discs together with enough force, leaving a small gap for water to pass through.

• Check if the cartridge or valve body has a specific direction or marking that must be in a certain position.
• Ensure the retaining nut is tightened firmly, but not overtightened, which could damage the cartridge.
• If the repair was done recently and dripping occurred immediately afterwards, incorrect installation is a more likely cause than new wear.

How to Accurately Determine Where the Water is Coming From

Before starting repairs, it's worth taking some time for careful observation – this will help you choose the correct repair strategy and save time and potentially unnecessary spare part purchases.

• With a dry, clean cloth, wipe the entire tap and its surroundings dry, then observe for a few minutes where the first drop appears.
• Check if dripping occurs only when a specific side (hot or cold) has been open, or in both cases.
• See if water comes directly from the spout, from under the lever, from the body joints, or from between the tap base and the sink.
• If dripping only occurs after using hot water, it may indicate thermal expansion within the cartridge, which is an additional sign of wear.

Tools and Materials Needed for Repair

Most tap repair jobs can be done with simple household tools, without immediately needing to call a specialist.

• Screwdriver (flathead and Phillips) for removing the lever cap and retaining screw.
• Spanner or adjustable wrench for loosening the cartridge retaining nut.
• New ceramic cartridge or washer set that precisely matches your tap model.
• Cleaning cloth, old toothbrush, and vinegar or descaler for limescale removal.
• Silicone grease for lubricating moving parts of the tap after reassembly – this extends the life of the new cartridge.

Step-by-Step Guide: How to Replace a Tap Cartridge Yourself

The following guide describes the most common repair – replacing the cartridge in a single-lever mixer tap. For a two-handle tap, the steps are similar, but you replace the valve spindle and washer instead of the cartridge.

• 1. Be sure to turn off both the hot and cold water isolation valves, which are usually located inside the under-sink cabinet or against the wall.
• 2. Open the tap lever fully and release any remaining pressure from the pipework before starting disassembly.
• 3. Remove the lever cap (this is often just a pressed-on plastic button) and the retaining screw beneath it.
• 4. Carefully lift off the lever, exposing the cartridge retaining nut.
• 5. Use a spanner to loosen the retaining nut and carefully lift out the old cartridge.
• 6. Clean any dirt and limescale from the cartridge housing in the tap body before inserting the new cartridge.
• 7. Place the new cartridge in the exact same position and orientation as the old one – most cartridges have a small notch or pin for this.
• 8. Replace the retaining nut, tighten it firmly, but do not overtighten.
• 9. Reattach the lever, secure the screw, and replace the cap.
• 10. Slowly open the isolation valves and check that the tap now fully shuts off without dripping.

Two-Handle Tap Washer Replacement – How it Differs

For a traditional tap with two separate handles, the repair logic is similar, but the parts you replace are different.

• Close the isolation valves and open the tap to release pressure from the pipework.
• Remove the tap handle and the cap or screw beneath it.
• Unscrew the valve spindle (spindle rod with washer) with a spanner.
• Check the rubber washer at the end of the spindle – if it's flat, cracked, or hardened, replace it with a new one.
• If the spindle itself is worn or rusted, it's cheaper and more sensible to replace the entire spindle, not just the washer.
• Reinsert the spindle, tighten it, and check that the tap now fully shuts off.

How to Prevent Tap Dripping in the Future

Some causes of dripping are natural wear and tear that cannot be entirely avoided, but by following a few simple steps, you can significantly extend the life of your tap.

• Avoid moving the tap lever with excessive force – a gentle movement is always better for the cartridge than an abrupt full turn.
• If your water is very hard, consider installing a whole-house water filter or anti-limescale device, which will reduce limescale build-up in all taps and appliances simultaneously.
• Regularly clean the tap aerator (spout tip) of limescale, as a clogged aerator increases pressure on the cartridge.
• Have your water pressure checked once a year, especially if you live in an area where central water pressure fluctuates frequently.
• When buying a new tap, choose a reputable manufacturer whose cartridges are widely available even years later – this simplifies future repairs.

When Is It Sensible to Call a Plumber?

While most tap dripping issues can be resolved independently, there are situations where it's advisable to call an experienced specialist.

• If you are unsure which cartridge or spare part fits your tap, or if the tap is an unusual model or age.
• If dripping continues after replacing the cartridge or washer, and you suspect a problem with the pipework or water pressure.
• If the tap body itself is cracked, fractured, or leaking from connection points, not just the spout.
• If the isolation valves themselves are jammed or leaking, making safe DIY repair difficult.
• If you live in an apartment building and the problem might be related to the common water supply system, not just your own tap.

Summary: Three Most Common Causes

If your tap drips after shutting off the water, first check the three most common causes – these cover most cases.

• The ceramic cartridge is worn, scratched, or clogged with limescale – replace the cartridge or clean it thoroughly.
• The rubber washer or O-ring has hardened or cracked – replace the washer; it's an inexpensive and simple fix.
• Water pressure in the house is too high – have a specialist measure the pressure and consider installing a pressure reducer.