The short answer
The clearest way to know is the water meter test: turn off everything that uses water, read the meter, wait 30 to 60 minutes, then read it again. If the numbers have moved with nothing running, you almost certainly have a leak. Rising bills, damp patches and the sound of running water back this up.
A water leak rarely announces itself. More often it shows up as a bill that creeps higher month after month, a patch of damp that will not dry out, or a faint hiss in the pipework when the house is quiet. The good news is that you can confirm a leak yourself in under an hour, with nothing more than your water meter and a little patience. This guide walks you through the meter test step by step, the other signs worth watching for, how to work out whether the problem sits inside your home or out on the supply pipe, and the point at which it makes sense to call a specialist.
The water meter test, step by step
This is the most reliable check you can do at home, and it is the same method the water companies recommend. Most homes in Devon have a meter either in a small chamber near the boundary of the property (lift the outer cover and you will usually find a second lid beneath it) or, in some cases, inside under the kitchen sink. Here is how to run the test.
- Turn everything off. Close every tap, and switch off appliances that draw water, such as the washing machine, dishwasher and any automatic systems. Make sure nobody flushes a toilet during the test.
- Take a reading. Find the meter, note down all the figures, including the smaller red dials or numbers that measure fractions of a unit. A photo on your phone is the easiest way to record it accurately.
- Wait 30 to 60 minutes. Leave the water untouched. The longer you wait, the more obvious a slow leak becomes.
- Read it again. Compare the two readings. If they match exactly, water is not escaping while everything is off, which is reassuring. If the figures have moved, water is going somewhere it should not.
Some newer meters have a small flow indicator, often a tiny star or triangle, that spins when water is moving. If it is turning with every tap closed, that alone is a strong sign of a leak.
Other signs that point to a leak
The meter test is the proof, but several everyday clues often raise the suspicion first. None of these is conclusive on its own, yet when two or three appear together it is well worth running the test above.
Signs you might notice:
- A water bill that keeps climbing while your usage habits stay the same
- Damp patches on walls, floors or ceilings, or paint and wallpaper that bubbles or lifts
- A musty smell or unexplained mould, often a sign of moisture trapped out of sight
- A noticeable drop in water pressure at the taps
- The sound of running or hissing water when every tap is off
- An area of the garden or driveway that stays soggy or unusually green in dry weather
Is the leak inside your home or on the supply pipe?
Once the meter test confirms water is escaping, the next question is where. The dividing line is your internal stop tap, usually found under the kitchen sink, in a downstairs bathroom or in an adjoining garage. Pipework and fittings beyond that point, inside the house, are internal. The buried pipe running from the stop tap out towards the boundary is your supply pipe.
To narrow it down, repeat a shortened version of the meter test:
- With all taps and appliances already off, take a meter reading.
- Now close your internal stop tap, which shuts off the water supply to the house.
- Wait around 15 minutes, then read the meter again.
If the meter stops moving once the stop tap is closed, the leak is on the internal side, somewhere in your household pipes, fittings or appliances. If the meter keeps ticking over even with the stop tap shut, water is escaping on the buried supply pipe between the meter and the house. Knowing which side the leak sits on matters, because in most cases the supply pipe is the homeowner’s responsibility to repair, while the water main in the road belongs to the water company. Many water companies offer a one-off free or subsidised repair on a customer’s supply pipe, so it is always worth asking South West Water what help is available before you arrange work.
A small internal leak is often easier to track down: a dripping overflow, a running toilet that never quite settles, or a weeping joint under a sink. A leak on a buried supply pipe is far harder, because the water disappears into the ground and may surface metres away from the actual fault, if it surfaces at all. That is usually where do-it-yourself investigation reaches its limit.
When DIY ends and a specialist helps
The meter test tells you whether you have a leak and roughly which side it is on. What it cannot do is pinpoint the exact spot, and that is the part that saves you from digging up a whole garden or lifting an entire floor on guesswork. Once you know water is escaping but cannot see where, a specialist leak detection survey is the sensible next step.
Professional leak detection uses non-invasive equipment, such as acoustic listening gear that hears water escaping under pressure, thermal imaging that reveals temperature differences from a hidden leak, and tracer gas that finds the smallest of faults. The aim is to locate the leak precisely before any flooring is lifted or ground is opened, keeping disruption and repair costs to a minimum.
It is worth getting expert help sooner rather than later if your meter is still moving but you cannot find the source, if damp or mould is spreading, if your pressure has dropped noticeably, or if your bills have jumped with no obvious explanation. Our water leak detection service covers homes and businesses right across Devon, and you can find more practical guidance in our articles. Catching a leak early protects your home, keeps your bills under control and avoids the far larger bills that come with water damage left to spread.
Frequently Asked Questions
Between 30 and 60 minutes with everything switched off is usually enough to show a leak. A slow leak may need the longer end of that window to move the meter noticeably, so if a half-hour test looks inconclusive but you still have doubts, leave it for an hour and read again.
Meters are often in a covered chamber near the front boundary of the property, by the pavement or driveway. Lift the outer cover and you may find a second insulated lid underneath. Some homes have an internal meter near the stop tap instead. If you genuinely cannot locate one, South West Water can tell you where yours is.
Yes. A leak that seems minor can waste a surprising amount of water over weeks and months, pushing up a metered bill steadily. More importantly, water finds its way into walls, floors and foundations, where the resulting damage is far more expensive to put right than the leak itself.
The supply pipe running into your home is generally the homeowner’s responsibility, while the water main in the road belongs to the water company. Many companies offer a one-off free or subsidised repair on a customer’s supply pipe, so check with South West Water what support they provide before arranging any work.
It can. Leaks on buried supply pipes or under solid floors often release water straight into the ground, so the only outward sign is a rising metered bill. This is exactly why the meter test is so useful, and why a specialist survey is worthwhile when water is clearly escaping but nothing is visible.
Still not sure where the water is going?
If your meter is still moving and you cannot find the source, our team can pinpoint the leak quickly and without unnecessary digging, anywhere in Devon.