The short answer
Turn off every tap and water-using appliance, then read your meter twice, an hour or two apart, using no water in between. If the reading climbs, you have a leak. Next, close your internal stop tap and repeat. That second test tells you whether the leak is inside or on your buried supply pipe.
A water meter is one of the most useful tools you have for spotting a hidden leak, and it costs nothing to use. If your bills have crept up, you can hear running water with the taps off, or you simply want peace of mind, a meter test is the sensible first step. It is straightforward, takes very little equipment, and gives you a clear answer about whether water is escaping somewhere it should not be.
Below is the method we use ourselves before bringing out any specialist kit. Work through it carefully and write your readings down as you go.
Step one: find your meter and learn to read it
Most Devon homes have their meter in a small chamber near the front boundary, often under a round or rectangular plastic cover in the pavement, drive or garden. Some are inside, near where the mains pipe enters the property. Lift the cover carefully, as the chamber can collect water and debris, and clear any leaves or grit off the face of the meter.
A typical meter shows a row of numbers, much like a car odometer. The black or white digits on the left record cubic metres of water used. The figures on the right, usually in red, record fractions of a cubic metre, right down to small dials or a single spinning needle. Those red figures are the important ones for leak testing, because they move even when only a tiny amount of water is passing through. If the meter has a star, triangle or small rotating wheel, that is a flow indicator, and it spins whenever water is moving.
Step two: the whole-property test
The first test checks whether any water at all is escaping while nothing is meant to be running. Turn off every tap in the house, switch off the washing machine and dishwasher mid-cycle if needed, and make sure nobody flushes a toilet or runs a shower during the test. Leave the internal stop tap open for now. If you have an automatic garden irrigation system or a water softener that regenerates overnight, switch those off too, as they can use water without anyone noticing.
Now read the meter and write down every digit, including the red ones. Note the position of any spinning needle. Leave everything untouched for one to two hours, then read the meter again. A handy version of this is to take a reading last thing at night and another first thing in the morning, when you can be confident no water has been used.
If the second reading is exactly the same as the first, no water moved and you almost certainly have no leak. If the reading has gone up, or the flow indicator was turning while everything was off, water is escaping somewhere. The next step narrows down where.
Step three: isolate the inside of the house
Your internal stop tap is the valve that shuts off water to the whole property. It is most often under the kitchen sink, but it can also sit in a bathroom, downstairs cloakroom, utility room, garage or near the front door. Turn it clockwise until it stops. To confirm it has fully closed, open the kitchen cold tap and let it run until the flow trickles to nothing. If water keeps running freely, the stop tap may not be shutting fully or may be worn, which is worth noting in its own right.
With the stop tap closed and the inside of the house now isolated, take a fresh meter reading. Wait another one to two hours, using no water, then read it once more. Compare the two parts of the test, because the contrast between them is what reveals where the leak is hiding.
Step four: read what the meter is telling you
There are three likely outcomes, and each points you in a different direction.
The meter moved during the first test but stopped once the stop tap was closed. This strongly suggests the leak is inside the property, on the pipework or fittings beyond the stop tap. Common culprits are a dripping overflow, a passing toilet valve, a slow joint under a sink or a fault on the central heating filling loop.
The meter kept moving even with the stop tap closed. This points to a leak on the underground supply pipe, the buried run between the meter and your stop tap. These leaks are often invisible above ground because the water soaks away into the soil. This is the type that usually needs specialist tracing equipment to pinpoint without digging up the whole garden.
The meter did not move at all in either test. No leak was running while you tested. If you still suspect a problem, it may be intermittent, so it can be worth repeating the test on another day or over a longer period.
Signs that point to a hidden leak:
- Water bills creeping up without any change in how much you use
- The sound of running water when every tap is off
- A patch of lawn that stays lush, green or boggy in dry weather
- Damp, warm spots on a solid floor, or a drop in water pressure
- The meter flow indicator turning when nothing should be running
Who is responsible for the repair?
As a general rule, the water company looks after the mains up to the boundary of your property, where the external stopcock usually sits. From that point onwards, the buried supply pipe and everything inside the house is the homeowner’s responsibility to maintain and repair. So a leak found between your meter and your internal stop tap, or anywhere in the house, will typically fall to you to put right.
There is some good news for metered homes in Devon. South West Water runs schemes that can help with the cost of a supply pipe leak, including a possible contribution towards repair or renewal and a leak allowance that credits your bill for the water lost once the leak is fixed. The exact terms and amounts can change, so check directly with South West Water for what currently applies to your situation, and keep any receipts from the repair.
When to bring in a professional
A meter test tells you whether water is escaping, and roughly where it is, but it will not show you the precise spot on a buried pipe. If your test points to a leak on the underground supply, or you cannot trace an internal leak yourself, that is the moment to call a leak detection specialist. We use methods such as acoustic listening equipment, tracer gas and thermal imaging to find the exact location, which means any digging or repair work can be kept small and targeted rather than guesswork.
If you would like a hand, our water leak detection service covers homes and businesses right across Devon. You can also browse our other guides over on the articles page.
Frequently Asked Questions
One to two hours with no water used is usually enough to show a clear difference if water is escaping. For a small or slow leak, a longer gap gives a more reliable result, which is why many people read the meter at bedtime and again first thing in the morning when the house has been still overnight.
It is most commonly under the kitchen sink, but check bathrooms, utility rooms, downstairs cloakrooms, garages and near the front door where the mains enters. It is a good idea to know where yours is before you ever need it in an emergency, so locating it now is time well spent.
Not always. Before you decide, rule out anything that draws water quietly, such as a toilet that keeps refilling, a dripping overflow, a water softener regenerating or an automatic garden system. Once you are sure nothing is meant to be running, a turning meter does point to a genuine leak.
It usually means the leak is on the buried supply pipe between the meter and your stop tap, rather than inside the house. These underground leaks rarely show on the surface and are best traced with specialist equipment so the repair can be kept small and precise.
Possibly. Metered customers in Devon may be able to apply to South West Water for a leak allowance, which credits the bill for water lost once a qualifying leak is repaired. Terms vary, so check the current details with South West Water and hold on to your repair receipts.
Generally, the water company maintains the mains up to your boundary, and the supply pipe and internal plumbing beyond that point are the homeowner’s responsibility. A leak between your meter and stop tap, or inside the house, will normally be yours to repair, though support schemes may help with the cost.
Not sure where the water is going?
If your meter test points to a hidden leak, our Devon team can pinpoint it without tearing up your home or garden.