Leaking Tap or Mixer: Causes, Water Waste & Repairs

JR PLUMBING LEARNING CENTRE

Leaking Taps, Mixers & Fixtures: Causes, Water Waste & Repairs

Find where the water is coming from, understand what may have failed and estimate how much water the leak could be wasting.

A tap can leak from the spout, handle, base, body, connection or flexible hose. The location of the water usually gives the best first clue about whether the problem involves a washer, cartridge, seal, O-ring, fitting or the fixture itself.

A Drip and a Leak Around the Base Are Different Faults Water continuing from the outlet when the tap is off usually points toward the internal shut-off mechanism. Water escaping around the handle, base or pipe connection points toward a different seal or connection.
✓ Water-waste estimator ✓ Tap & mixer diagnosis ✓ Repair vs replacement
LEAK & WATER WASTE ESTIMATOR

How Much Water Could the Tap Be Wasting?

Choose what the leak looks like and how frequently it drips. The calculator provides an approximate daily and annual water volume.

APPROXIMATE WATER LOSS —
— litres per day
— litres per year

—

Estimate only. Individual droplets vary considerably in size, and a leak that has progressed to a trickle or stream can waste substantially more water than a regular drip.

QUICK ANSWER

Why Does a Tap Keep Dripping After It Is Turned Off?

A tap drips when its internal shut-off mechanism no longer seals completely.

In traditional taps this may involve the washer, valve seat, O-ring or spindle assembly. In many modern mixer taps, water flow is controlled by a cartridge rather than a conventional washer.

The exact cause depends on the tap design and where the leak appears. Water from the spout, handle, base and pipe connections should not automatically be treated as the same fault.

Where Is the Tap Leaking From?

The location of the water is often the fastest way to narrow down which part of the fixture needs attention.

SPOUT

Dripping From the Outlet

If water continues from the spout after the tap is fully closed, the internal flow-control mechanism is not sealing completely.

HANDLE

Water Around the Handle

Water appearing around a handle or spindle can point toward internal seals or O-rings rather than the main outlet seal.

MIXER BASE

Leak Around the Base

Water around the body or base of a mixer can involve seals, mounting areas, swivel-spout O-rings or internal fixture leakage.

UNDER SINK

Flexible Hose Leak

Water under a sink or vanity may come from the flexible inlet hose, connection, isolation valve or another fitting rather than the mixer itself.

BODY

Fixture Body Is Leaking

Cracks, corrosion or internal failure within the tap body may make replacement more practical than rebuilding individual components.

UNKNOWN

Water Appears Nearby

Water can track along pipework, benchtops and cabinetry before becoming visible, so the wettest point is not always the original source.

Leaking Tap Symptoms and Possible Causes

What You See Possible Area What It May Need
Constant drip from spout Washer, cartridge or valve seat Internal tap servicing or component replacement
Leak around handle while tap is on Spindle seal, O-ring or cartridge area Seal or internal component inspection
Water around mixer base Base seal, swivel seals or internal mixer body Identify exact source before repair
Water inside cupboard Flexible hose, isolation valve or connection Connection and hose inspection
Tap difficult to turn Internal wear, spindle or cartridge Service or replacement depending on condition
Leak returns after repair Seat damage, pressure, worn body or incorrect component Further diagnosis rather than repeating the same repair

Washer Tap vs Mixer Tap: Why the Repair Is Different

“Change the washer” is not a universal answer because many modern fixtures do not use a traditional washer to control the water.

Traditional Compression Tap

Turning the handle lowers a mechanism that seals against the valve seat. Washers, O-rings, spindles and the valve seat can all influence whether it shuts off properly.

Ceramic Disc Tap

Ceramic-disc designs use precision internal components rather than a conventional rubber washer. Wear or damage generally requires the correct internal component rather than a generic washer.

Single-Lever Mixer

Many single-lever mixers use a cartridge that controls both flow and temperature. Cartridge wear can lead to dripping, stiffness or poor temperature control.

Swivel Kitchen Mixer

These can leak from the cartridge, swivel-spout seals, base, flexible connections or pull-out hose depending on the design.

Wall-Mounted Mixer

Leaks behind or around a wall-mounted fixture can require more care because concealed connections may be involved.

Outdoor Tap

Outdoor taps may use traditional washer-type mechanisms, but leaks can also occur at the body, spindle, connection or pipework supplying the fixture.

WATER WASTE

How Much Water Can a Dripping Tap Waste?

The answer depends on droplet size and drip rate. A tap dripping once every few seconds may look insignificant, but it operates 24 hours a day unless someone turns the water off or repairs the fault.

Slow Drip

A slow intermittent drip may only release a small quantity at a time, but the total continues building every hour and every day.

Fast Drip

Once the frequency reaches several drips every second, the annual water loss can become substantial compared with the visual size of the leak.

Continuous Trickling

A visible stream is no longer well represented by a simple drip calculation and can lose much more water than the calculator above estimates.

A leaking hot tap can waste more than water. If heated water is continuously escaping, the hot-water system may also need to replace and reheat that lost water, depending on the fixture and system arrangement.

Common Parts That Can Cause a Tap to Leak

WASHER

Tap Washer

In a traditional compression tap, the washer forms part of the shut-off seal against the valve seat.

CARTRIDGE

Mixer Cartridge

The cartridge in a mixer can control flow, temperature or both. Internal wear can allow water to pass even when the lever is closed.

O-RING

O-Rings & Seals

O-rings seal moving or joined sections such as handles, spouts and mixer bodies and can leak when worn, damaged or displaced.

SEAT

Valve Seat

A new washer cannot seal properly against a badly worn or damaged seating surface.

HOSE

Flexible Connector

Flexible hoses supply many mixers and can leak from the hose itself or either connection point.

FIXTURE

Tap Body

Physical damage, corrosion or internal deterioration can make replacing the complete fixture more practical than replacing individual seals.

Should a Leaking Tap Be Repaired or Replaced?

The cheapest component repair is not always the best long-term option, especially when the fixture itself is old, damaged or repeatedly failing.

Repair May Make Sense When:

  • The fixture is otherwise in good condition.
  • The correct washer, cartridge or seal is available.
  • The body is not cracked or corroded.
  • The fault is clearly isolated to a serviceable component.
  • The tap is worth retaining.

Replacement May Make More Sense When:

  • The fixture has several worn components.
  • The tap body itself is leaking.
  • The correct internal parts are unavailable.
  • The existing fixture has repeated faults.
  • Labour to rebuild the old fixture approaches replacement value.

Can Water Pressure Contribute to Leaking Taps?

Pressure is not the only reason fixtures leak, but excessive or abnormal pressure can increase stress on valves, seals, flexible hoses and other plumbing components.

One Tap Leaking

A problem isolated to one fixture more strongly suggests a local fixture fault than a property-wide pressure problem.

Multiple Fixtures Failing

Several new leaks, noisy valves or repeated fixture problems can justify looking beyond the individual tap and considering the broader water supply.

Water Hammer or Noise

Banging or pressure-related noise is a separate symptom and should be diagnosed from the wider plumbing system rather than assumed to be caused by the leaking tap.

What if the Water Is Leaking Under the Sink?

Do not automatically assume the mixer itself is leaking.

Under a sink or vanity, water can come from the hot or cold flexible hoses, isolation valves, mixer connections, waste pipework, sink waste, dishwasher connection or water running down from above.

Drying the area and observing exactly where fresh water first appears can help separate a pressurised water leak from drainage water or a spill from the sink above.

When Should a Leaking Tap or Mixer Be Looked At?

Constant Dripping

A leak that continues whenever the fixture is off is wasting water continuously and is unlikely to repair itself.

Water Entering Cabinetry

Leaks inside vanities or kitchen cabinets can damage cabinetry and surrounding materials if left unresolved.

Flexible Hose Leaking

A pressurised hose or connection leak can worsen and may release considerably more water if the component fails further.

Fixture Body Cracked

A damaged body generally cannot be treated in the same way as a simple washer or cartridge fault.

Leak Keeps Returning

Repeated repairs can indicate a seating, pressure, body or component compatibility problem that requires broader diagnosis.

Several Fixtures Have Issues

Multiple simultaneous fixture problems can justify checking whether there is a wider plumbing condition contributing to them.

LEAKING TAP FAQ

Frequently Asked Questions About Leaking Taps & Mixers

Why does my tap keep dripping after I turn it off?

The internal flow-control mechanism is not sealing completely. Depending on the tap design, the cause may involve a washer, cartridge, valve seat or another internal sealing component.

Does every leaking tap just need a new washer?

No. Many modern mixers use cartridges rather than traditional washers, and leaks can also come from O-rings, valve seats, flexible hoses, connections or the fixture body.

Why is my mixer tap leaking from the base?

Water around the base can come from swivel-spout seals, internal mixer seals, mounting areas or water tracking down from another part of the fixture. The exact source needs to be identified before choosing the repair.

Why is water leaking around the tap handle?

A handle-area leak can involve spindle seals, O-rings, the cartridge or another internal component. This is different from a tap that only drips from the outlet while turned off.

How much water does a dripping tap waste?

It depends on the size and frequency of each drop. Even a slow drip continues all day and all night, so the annual volume can be much larger than the individual droplets suggest. The calculator at the top of this page provides an approximate estimate.

Can a leaking hot tap increase energy use?

Potentially. If heated water is continuously being lost, the hot-water system may need to replace and heat additional water depending on the system arrangement and the location of the leak.

Why is there water under my kitchen sink?

Water under a kitchen sink can come from mixer hoses, isolation valves, supply connections, the sink waste, dishwasher connections or water running down from the benchtop or mixer above. The visible puddle is not always directly beneath the source.

Can a flexible tap hose leak?

Yes. Flexible inlet hoses and their connections can leak. Because they are connected to the pressurised water supply, deterioration or failure can release more water than a simple dripping spout.

Should I repair or replace an old leaking mixer?

Consider the fixture's condition, age, availability of compatible parts, number of worn components and the cost of servicing compared with replacing the complete mixer.

Can high water pressure make taps leak?

Excessive pressure can increase stress on fixtures, seals, valves and flexible hoses. A leak isolated to one tap may still simply be a local fixture fault, while repeated problems across several fixtures may justify broader pressure investigation.

Why did my tap start leaking again after a new washer?

The washer may not be the only issue. The valve seat, spindle, pressure conditions or another component may also affect the seal, so repeatedly changing the same part does not always resolve the underlying cause.

When is a leaking tap more urgent?

A leak becomes more urgent when water is escaping continuously under pressure, entering cabinetry or walls, affecting electrical equipment, coming from a flexible hose or connection, or increasing rapidly.

Tap, Mixer or Fixture Still Leaking?

Whether the water is dripping from the spout, appearing around the mixer, leaking under the sink or returning after previous repairs, the source needs to be identified before the correct washer, cartridge, seal, connection or fixture can be dealt with.