Why Is My Tap Making Noise When Not in Use?

If you notice a tap or pipe making noise even when no water is running, it can be unsettling.

Most people assume something is broken.

In many cases, it isn’t.

Plumbing systems often make sounds that feel abnormal but are actually common, especially in older homes or shared water systems.

This page explains what those noises usually mean — and when they matter.

What Kind of Noise Is It?

The meaning depends more on the type of sound than the fact that there is a sound.

Low humming or vibration

Often caused by pressure changes in the water supply.

This can happen when nearby properties use water, even if you aren’t.

Brief knocking or tapping

Common when pipes expand or settle slightly.

This is especially noticeable after temperature changes.

Faint whistling

Usually linked to water flowing elsewhere in the system.

It can travel through pipework and seem local to your tap.

Intermittent clicking

Often related to valves opening or closing elsewhere.

It doesn’t always indicate a fault near the tap itself.

None of these automatically mean damage is occurring.

Why It Happens When You’re Not Using Water

Plumbing is a shared, pressurised system.

Even when your taps are off:

• Water pressure still fluctuates
• Pipes still expand and contract
• Valves still respond to system demand
• Flow elsewhere can transmit sound

Noise doesn’t require active use to occur.

Is This Usually a Problem?

In most homes, occasional or faint noise is normal.

It’s especially common if:

• The house isn’t new
• Pipes run through walls or cupboards
• Water pressure varies by time of day
• Other properties share supply lines

If the noise:

• Comes and goes
• Doesn’t worsen over time
• Stops on its own

…it’s rarely urgent.

When Noise Is More Likely to Matter

Sound alone isn’t the issue.

Change is.

Pay attention if the noise:

• Suddenly becomes much louder
• Starts happening constantly
• Is accompanied by visible leaks
• Coincides with pressure loss or water marks

Those combinations suggest the system is under strain, not just making harmless sound.

Why Plumbing Sounds Often Stop by Themselves

Many plumbing noises are caused by temporary conditions:

• Pressure equalising
• Temperature changes
• Short-term demand elsewhere

Once the system stabilises, the noise fades.

That’s why many people notice sounds at night or early morning, then never again.

The Calm Way to Think About It

A useful rule of thumb:

Noise without change is usually observation, not action.

If nothing else is happening — no leaks, no loss of pressure, no spread of damage — monitoring is often enough.

Plumbing systems are quieter than we expect, but not silent.