How to do a water meter leak test

A water meter leak test is the simplest way to find out if water is escaping from your pipes. It costs nothing and needs no tools beyond a torch and a pen. Bristol Water publishes its own step by step method. This guide walks through it, explains what the result means, and covers what to do next.

We often use this test with people in Kingswood, Hanham and the rest of South Gloucestershire, where many homes are Victorian Pennant stone terraces or interwar and post war semis with long front gardens. A long garden means a long supply pipe, and more room for a hidden leak. Our Kingswood area page covers the housing there.

Before you start

Make sure nothing in the house is using water:

• All taps off, inside and outside.
• Washing machine and dishwasher not running.
• No toilet refilling.
• Combi boiler not heating hot water.
• Water softener not regenerating. Many do this at night, so check its settings.
• Loft tank not filling. If you have one, listen at the hatch.

Bristol Water also suggests checking that no overflow pipes are dripping outside, and that no tap or appliance is dripping or failing to shut off.

The test, step by step

This follows Bristol Water’s leak test.

1. Find your meter. It is usually in a pavement box or just inside your boundary. Lift the lid and clear any soil or water so you can see the dial.
2. Take a reading. Write down every number on the dial, including the red ones. Some meters also have a small spinning star or wheel that moves when any water flows.
3. Wait without using water. Bristol Water suggests overnight, or the length of a working day.
4. Take a second reading.
5. Compare.

Result	What it means
Readings the same	No leak
Readings different, meter is inside the house	The leak must be inside the property
Readings different, meter is outside	Go to the next step

If your meter is outside

Bristol Water’s next step is to shut your inside stop tap and repeat the test. The inside stop tap is usually under the kitchen sink, or where the pipe comes into the house. In older Bristol terraces it can be in a cellar, under the stairs or behind a panel in the front room.

Result after shutting inside stop tap	What it means
Meter stops moving	Leak is inside the house, after the stop tap
Meter still moving	Leak is on the supply pipe between the meter and the house

If the inside stop tap is missing or will not turn, Bristol Water says you will need one fitted before you can finish the test. That is a small job, and worth doing anyway. You need a working stop tap in a burst.

What to do with the result

Leak inside the house. Check the usual suspects first:

• Toilets. Put a few drops of food colouring in the cistern. If it shows in the bowl after half an hour without flushing, the flush valve is letting by. Our guide to a toilet that keeps running covers the fix.
• Dripping taps.
• Loft tank overflows.
• Damp patches on ceilings or floors.

If none of those explain it, the leak may be hidden in a wall or under a floor. Our guide to a leak under the floorboards explains how they are traced.

Leak on the supply pipe. This is the pipe from the boundary into your home. It is your responsibility, but Bristol Water offers help:

• Up to half an hour of free leak detection, with advice.
• An automatic £100 subsidy to homeowners once the repair is confirmed.
• £250 if you replace the leaking supply pipe within 21 days.
• A leakage allowance on a metered bill if the repair is made within 21 days.

Our guide to Bristol Water leaks and who pays goes through those in more detail.

Signs of a supply pipe leak in the garden

In Kingswood and Hanham, where many homes sit back from the road, look along the line from the pavement box to the front wall of the house:

• A patch of lawn that stays green in a dry spell.
• A damp area on a path or drive that never dries.
• A sound of running water at the stop tap with everything off.
• Lower pressure than you used to have.

During the 2026 drought, when Bristol Water brought in a hosepipe ban, a green strip across a brown lawn was an easy clue to spot.

Is the meter itself leaking?

If water is pooling in the meter box, the leak may be on the meter or its fittings. That is usually Bristol Water’s to look at. Contact them with photos.

When to call a plumber

Call for help if:

• The meter is moving and you cannot find the cause.
• The leak is on the supply pipe.
• Your inside stop tap is seized.
• You have damp or staining appearing indoors.

Our leak detection page explains how hidden leaks are traced and what the visit involves. We do not publish fixed prices. The cost is confirmed after a look at the job.