The water meter test: find a hidden leak in half an hour

If your water bill has jumped, there's an unexplained damp patch, or you can faintly hear water moving when everything's off, your water meter can settle the question. It measures everything entering the house — so if nothing should be running and the meter says otherwise, water is escaping somewhere.

The test

• Make sure nothing is using water: taps off, washing machine and dishwasher idle, nobody flushing, and any garden irrigation off.
• Find the meter — usually under a small cover in the footpath outside, sometimes inside near the stop tap.
• Note the full reading, including the red digits, or watch the small spinning indicator — on most meters it turns with even a tiny flow.
• Wait 30–60 minutes with no water used, then read it again. Any movement means a leak.

Narrowing it down

Now close the internal stop tap and watch the meter again. If the movement stops, the leak is inside the house — somewhere past the stop tap, and findable. If the meter keeps creeping with the stop tap closed, the leak is on the underground supply pipe between the meter and the house — which as the homeowner is usually yours to fix from the property boundary, though many water companies help with a first-time supply pipe repair. Worth phoning yours before commissioning anything.

One meter myth

A dropping boiler pressure gauge is a different thing — the heating circuit is sealed and separate from the mains, so the meter won't see that leak. Our boiler pressure guide covers that one.