Leak Repair vs Leak Detection: What to Do When You Find a Leak

Reviewed by the DCI Leak Detection team · Last updated June 2026

Almost everyone who finds a leak types the same thing into a search box: how do I fix it. It is the right instinct, but there is a step most people skip. You cannot repair a leak properly until you know exactly where it is, and with most leaks that is the hard part. So the honest answer to "how do I fix a water leak" is a short sequence: stop the water, find the leak precisely, then repair it. This guide walks through each step and explains where leak detection and leak repair are two different jobs.

Leak detection vs leak repair: the difference

These two words get used as if they mean the same thing. They do not, and the difference matters when you are deciding who to call.

Leak detection is finding exactly where the water is escaping. With a hidden leak, under a floor, inside a wall or in a buried pipe, this is a skilled job using thermal imaging, acoustic listening and tracer gas to pinpoint the source without ripping anything out. Leak repair is the physical fix once the leak is found: replacing a section of pipe, a fitting, a joint or a seal. They are separate jobs, often done by different people. A detection specialist locates and documents the leak; a plumber or contractor then carries out the repair.

This is exactly how DCI works. We are a detection specialist, so we pinpoint the leak and hand you a precise location plus an insurer-ready report. We do not do the plumbing repair itself. Your own plumber, or one you choose, makes the fix, and because the leak is already located to a small area, that repair is far more straightforward.

The three steps when you find a leak

Whatever the leak, the order of play is the same. Follow these three steps and you avoid the most common, and most expensive, mistakes.

Step 1: Stop the water

If water is actively escaping, turn off the internal stop tap first. It is usually under the kitchen sink, though it can also be in a downstairs toilet, utility room, garage, cellar or under the stairs. Turn it clockwise, slowly, and do not force it. Then turn off the heating, and you can open the taps to drain the system and ease the pressure. South West Water's neighbours such as Southern Water and the industry body WaterSafe all give the same advice. If the stop tap is seized or you cannot isolate the supply, your water company can isolate it in an emergency.

Step 2: Find it precisely

With the immediate flow under control, the next job is to locate the leak exactly. If it is visible, such as a dripping tap or a wet joint under the sink, you have found it. If it is hidden, which many leaks are, this is where detection comes in. The signs that a leak is hidden include a metered bill that keeps rising, a drop in pressure, the sound of running water with everything off, or damp that keeps returning. Our guide on how to find a water leak covers the home checks and the meter test in full.

Step 3: Repair it

Once the source is confirmed, the repair can be carried out, and only then. For a hidden leak that means a plumber or contractor opens up the one spot that has been pinpointed and fixes the pipe or fitting. For a simple visible leak it might be a new washer or a tightened connection. Either way, repairing comes after finding, never instead of it.

What leak detection is, and when you need it

Leak detection is the non-invasive process of locating a hidden leak before anything is cut open. A specialist uses several methods together, each cross-checking the others, so the source is confirmed rather than guessed at.

• Thermal imaging reads small temperature differences across a floor, wall or ceiling. A hot-water or heating leak shows as a warm trail; a cold supply leak shows as a cool one.
• Acoustic detection uses sensitive microphones to pick up the sound a pressurised leak makes as water escapes, which helps locate a buried pipe.
• Tracer gas is introduced into the pipework and rises to the surface at the exact point it is escaping, pinpointing the slow leaks that are otherwise almost impossible to find.
• Moisture meters confirm how far the dampness has tracked, narrowing the search to the true source rather than where the water happens to show.

You need detection when the leak is hidden: a leak under a solid floor, inside a stud wall, or in a heating pipe set in a screed can run for weeks with almost nothing to see, and the damp patch often sits well away from the actual source. That is the kind of leak DCI is built to find. Our water leak detection service explains how a job runs from first call to report.

What leak repair is, and who does it

Leak repair is the physical fix, and it is a plumbing job. Depending on what was found, it might be a replaced length of pipe, a new fitting or joint, a re-soldered connection, or a fresh seal. To be clear: DCI does not carry out the repair. We find the leak precisely and produce the documentation, then a qualified plumber or contractor does the fixing.

It is also worth knowing who is responsible for what. As a homeowner you are responsible for the supply pipe running from your property boundary into the house, and for the plumbing inside. The water company looks after the mains and the communication pipe up to the boundary. According to Ofwat and the Consumer Council for Water, many suppliers also offer a free or subsidised one-off supply-pipe repair, so it is always worth asking yours before you pay for outside work.

How finding it first makes the repair smaller

This is the part that saves people the most money and stress. When a leak is hidden, the temptation is to start lifting the floor or cutting the wall where the damp shows. Because water travels along joists and pipe runs before it appears, that is usually the wrong place, and you end up with a much bigger hole and the leak still running.

Detection turns that guessing game into a targeted job. The source is confirmed to a small area first, so the repair becomes one neat access point rather than a torn-out floor or ceiling. Less is opened up, the plumber knows exactly where to go, and the cost of making good afterwards is far lower. A small, well-aimed repair beats a big, speculative dig every time.

There is an insurance angle too. Many home policies include trace and access cover, which pays to find a hidden leak and make good the damage caused by reaching it. As insurers and comparison sites such as Confused.com and GoCompare explain, limits usually run between about five thousand and ten thousand pounds and vary by insurer. It does not normally pay to repair the pipe itself, so check your policy. A clear detection report is what many insurers want to see, and our trace and access service provides exactly that. If you are weighing up a claim, our guide to a water leak insurance claim walks through the process.

When it is a simple fix, and when it is not

Not every leak needs a specialist. Plenty are simple, visible and well within reach of a confident homeowner.

Often a simple do-it-yourself fix: a dripping tap or a worn tap washer, a loose washing-machine or dishwasher hose, a slightly weeping connection under the sink that just needs tightening, or sealant around a bath or shower that has perished. These are visible, you can isolate them, and the fix is cheap.

Needs locating before anyone repairs it: a meter that keeps moving with all the water off, damp that keeps returning, a heating system that loses pressure, a warm patch on a solid floor, or a rising bill with nothing to see. These point to a hidden leak. Cutting or digging blind here tends to make the damage worse, so the leak needs pinpointing first. If water is anywhere near light fittings or wiring, switch off the electricity at the consumer unit if it is safe, leave the fitting alone, and get it checked before going further.

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