Outside Tap Leaking: Causes, Checks & Fixes

Isolate the hot and cold supplies before dismantling a tap

Use local service valves or the main stopcock. Do not force seized valves or tap handles. Keep water away from sockets and appliances, and stop if a cracked tap body, failed flexi hose or uncontrolled leak is present.

MOST LIKELY CAUSES

Start with these

Worn washer The tap drips from the outlet when closed.

Spindle gland leak Water appears around the handle shaft.

Frost-damaged body A split may leak only under pressure.

Pipe or wall connection leak Water may run behind the fitting or inside the wall.

◫ Symptom variations Match the exact tap behaviour before repair. ⌄

Drips from spout
Leaks around handle
Water appears behind wall plate
Leak began after freezing weather
Tap body is cracked or distorted

✓ Quick checks Simple checks before removing tap parts. ⌄

Identify whether the fault affects hot, cold or both supplies.
Dry the tap and surrounding area to trace leaks accurately.
Check local isolation valves, flexible tails and visible connections.
Remove and inspect the aerator where flow is poor.
Do not force stiff handles, valves or seized fittings.

If the cause is found: keep the affected supply isolated until the correct repair is completed.

If the leak cannot be controlled: close the main stopcock and call a plumber.

1 Step 1 — Isolate the outside-tap supply Isolate water supplies before dismantling tap components. ⌄

Process

Use the indoor service valve or main stopcock.

Success looks like: The leak stops.

Escalate when: If not, another supply or trapped water may remain.

2 Step 2 — Dry and identify the leak point Isolate water supplies before dismantling tap components. ⌄

Process

Check the spout, spindle, body and rear connection separately.

Success looks like: The failed component is confirmed.

Escalate when: A wall-side leak may be concealed.

3 Step 3 — Leave frost-damaged taps out of service Isolate water supplies before dismantling tap components. ⌄

Process

Do not keep repressurising a cracked tap.

Success looks like: Further water damage is prevented.

Escalate when: Replace the tap and inspect the pipe behind it.

⌁ Common causes explained Why taps drip, seize, leak or lose flow. ⌄

An outside tap can leak from a worn washer, spindle gland, valve seat, body crack, frost damage or the pipe connection behind the wall.

Tap faults often come from small internal seals, cartridges, washers and local restrictions. Water can also track down the tap body and appear under the sink away from the true source.

⌘ Advanced diagnostics Plumber-level checks and repair work. ⌄

Replace washer or tap headgear.
Repack or replace gland seal.
Replace frost-damaged bib tap.
Inspect wall plate and rear pipe joint.
Fit suitable isolation and frost protection.

▣ Parts that may need replacing Common components linked to this fault. ⌄

Outside bib tap
Tap washer
Gland packing or O-ring
Wall plate elbow
Pipe fitting
Isolation valve

! When to call a plumber Conditions that should end basic troubleshooting. ⌄

The local isolation valves will not close or are leaking.
A flexible hose is bulging, split or corroded.
The tap body or pipe connection is cracked.
The tap is heavily corroded or inaccessible.
A thermostatic or pressure-balance fault creates a scalding risk.
The leak or poor flow remains after basic service work.

? Frequently asked questions Common questions about tap faults. ⌄

How do I know whether the tap uses a washer or ceramic cartridge?

Traditional screw-down taps usually use washers. Quarter-turn and many lever taps use ceramic cartridges.

Can I replace a cartridge with any similar-looking one?

No. Height, diameter, spline count and inlet layout must match.

Why is only one side of a mixer tap weak?

That side may have a partly closed valve, blocked hose, inlet filter or cartridge passage.