How to check for a water leak with your meter
Turn off every tap and appliance, read your meter, wait 30 minutes without using any water, then read it again. If the numbers have moved, water is escaping somewhere after the meter. This page times it and does the sums.
Before you start
ReadyThe test only works if nothing in the house is using water. Tick these off as you go.
Take your first reading
ReadThe main numbers are cubic metres. Type every number exactly as you see it, zeros at the front included. The red numbers matter most here: a small leak shows there first.
Wait without using any water
TimedThirty minutes suits most homes. Your first reading is saved on this device, so you can close the page and come back.
Save your first reading to start the timer.
Take your second reading
ReadRead the meter again before anyone uses water, in exactly the same way.
What your result means
Your result appears here after the second reading. No movement means no water passed the meter while you tested. Any movement means water got past it while everything was meant to be off.
Inside or outside? The stop tap test
If the meter moved, this tells you where the water is going. Close your internal stop tap, usually under the kitchen sink, and turn the kitchen tap on to check the water stops. Turn it off again, then read the meter, wait 15 minutes and read it once more.
Do not force a stiff or seized stop tap. If it will not turn, leave it and call a plumber or ADI.
With the stop tap closed, did the meter move?
Leaks to check inside the house
Start with the toilets. A toilet that trickles into the bowl can waste up to 400 litres a day and is easy to miss, because the water goes straight down the pan.
Toilets
Half an hour after a flush, dry the back of the pan and lay a dry sheet of toilet paper across it. Leave it a few hours without using that toilet. Wet or torn paper means the cistern is leaking into the bowl.
Taps and showers
A tap dripping once a second can waste up to 21 litres a day. Check the kitchen, bathroom and utility taps, and the shower head after it has been off for a while.
Overflow pipes
Look outside for a small pipe dripping from the wall or eaves. It usually drains a toilet cistern or a cold water tank in the loft whose valve is not shutting off.
Appliances
Pull out the washing machine and dishwasher and check the hoses and joints behind them. Check a water softener is not stuck mid cycle.
The outside tap
Check it for drips, and check the pipe that feeds it where it passes through the wall.
Pipes you cannot see
Damp patches, lifting floor tiles or a musty smell near pipework can mean a leak in a wall or under a floor. That needs a leak detection engineer.
If you do not have a water meter
Without a meter, a leak does not change your bill, but it can still damage your home. Two simple checks can still point to one.
Listen at the stop tap
Late in the evening, with everything off, put your ear close to the internal stop tap. A hiss or a steady rush of water with nothing running is a warning sign.
The glass of water test
This one needs two people and a stop tap key. One person fills a glass at the kitchen cold tap and keeps the end of the tap under the water. The other turns off the outside stop tap. Watch the glass for five minutes: if the water level falls, water is being drawn back down the pipe, which points to a leak on it.
Turning off an outside stop tap can cut off a neighbour on a shared supply. Check first, and do not force a stiff valve.
When to call ADI
Call if the meter keeps moving with the internal stop tap closed, if you can hear water you cannot see, or if the checks inside turn up nothing and the meter still moves.
ADI Leak Detection traces hidden leaks on water pipes with tracer gas, acoustic listening and thermal imaging. Their methods are chosen to avoid damage wherever possible, and they usually repair the leak on the same day where they can.
- 25 engineers
- Around 5,000 jobs a year
- England, Scotland and Wales
- Rated 4.7 on Trustpilot
ADI figures September 2026. Trustpilot 1,624 reviews, checked 25 September 2026.
Not sure yet? Check your water bill or read what happens when you call.