A damp patch spreading across a ceiling, a boiler that keeps losing pressure, or a water bill that suddenly climbs can all lead to the same question: who fixes leaks? The right answer depends on where the water is coming from, whether the pipework is visible, and how much evidence is needed for an insurance claim.

A standard plumber is often the right first call for an obvious fault, such as a dripping tap, leaking radiator valve or failed appliance connection. But when water is escaping behind a wall, below a floor, within a ceiling void or on a buried supply pipe, the priority is not simply to start removing finishes. It is to locate the source accurately.

That is where a leak detection and trace & access specialist is needed. They identify the leak using diagnostic equipment, minimise unnecessary damage, arrange targeted access and carry out or coordinate the repair and reinstatement work.

Who fixes leaks in visible plumbing?

For a leak you can see, a qualified plumber is usually the appropriate professional. This includes a leaking stopcock, toilet cistern, shower hose, sink waste, radiator, exposed copper pipe or washing machine connection. In many cases, the plumber can isolate the water, replace the failed component and test the repair during the same visit.

Do not underestimate a small visible leak. A slow drip beneath a kitchen sink can damage a cabinet, swell flooring and encourage mould before it becomes obvious. Equally, a radiator valve that only seeps when the heating is running may point to a pressure or component issue that needs prompt attention.

If the leak involves a boiler, gas appliance or sealed central-heating system, use an appropriately qualified heating engineer. Gas work must be handled by a Gas Safe registered engineer. A water leak around a boiler may not be a gas fault, but it still needs a competent assessment because pressure loss, electrical components and condensate arrangements can all be involved.

When a plumber needs a leak detection specialist

The situation changes when the leak is concealed. Water rarely appears directly below or beside the point of failure. It can travel along pipework, joists, insulation, screed or masonry before staining a wall or ceiling some distance away.

Signs that you may need specialist leak detection include recurring damp with no clear source, unexplained water-meter movement, mould in an otherwise dry area, warm patches on floors, a persistent drop in boiler pressure, distorted skirting boards, or the sound of running water when all outlets are off.

A general plumber may be able to investigate these symptoms, particularly in straightforward properties. However, opening floors and walls based on an assumption can quickly become expensive. If the source is unclear, a trace & access engineer brings a more controlled process: test the system, identify the likely pipe run, pinpoint the escape of water, then recommend the smallest practical area for access.

This approach matters in London flats, converted properties and homes with tiled bathrooms or finished timber floors, where exploratory works can create significant disruption. Finding the source before cutting is usually the best way to control both repair costs and damage to the property.

How hidden leaks are found without guesswork

No single test finds every leak. The method should be selected after the engineer has considered the symptoms, construction of the property, pipe material and whether the suspected leak is on mains water, heating pipework, waste pipes or a communal system.

Thermal imaging

Thermal imaging detects temperature differences across a surface. A hot-water or heating leak can create a distinct thermal pattern beneath a floor or behind a wall. It is particularly useful when used alongside pressure testing, rather than as a stand-alone answer. A cold-water leak may be more difficult to confirm with thermal imaging alone, especially where temperatures are uniform.

Acoustic testing

Pressurised water escaping from a pipe can produce sound and vibration. Sensitive acoustic equipment helps an engineer listen for that signature through floors, walls and external ground. Results depend on the pipe depth, building materials, background noise and the size of the leak, so experience in interpreting the reading is essential.

Tracer gas detection

Where appropriate, the system is isolated, drained and filled with a safe tracer-gas mixture. The gas escapes at the fault and rises through many common floor finishes or building materials, where a detector can identify it. This can be highly effective for concealed heating pipes and some water supply leaks, particularly when moisture is no longer visibly spreading.

Moisture mapping and pressure testing

Moisture meters help establish the extent and movement of dampness, while pressure testing confirms whether a water or heating system is losing pressure. These tests can separate an active leak from historic water damage, condensation or moisture entering through the building fabric. That distinction is critical before paying for invasive work.

A reliable diagnosis often comes from combining methods. The aim is evidence, not a best guess.

The difference between finding the leak and fixing it

Leak detection, access, repair and reinstatement are related but separate parts of the job. Understanding this makes quotes and insurance conversations much clearer.

The trace & access stage identifies the source and defines where access is needed. The repair stage may involve replacing a section of pipe, renewing a joint, repairing a waste connection or rerouting damaged pipework. Reinstatement then addresses the opening made to reach the fault, which could mean repairing plasterboard, tiles, flooring, decoration or a ceiling.

Some leak detection specialists provide the complete service, while others only diagnose the fault and leave repairs to a plumber or builder. Neither model is automatically better, but a full-service provider can reduce delays and avoid disputes over exactly where access is required.

Before work begins, ask what is included: diagnosis, isolation, trace & access, pipe repair, drying advice, photographic evidence, reinstatement and any return visit. A low initial investigation price may not cover repair works, while a fixed quote for a visible plumbing repair may be more suitable for a simple, confirmed fault.

Who fixes leaks when insurance is involved?

If an escape of water has damaged your home, insurer requirements can shape the process. Many policies may cover trace & access and resulting damage, subject to the policy terms, excess and the cause of the leak. They do not always cover the cost of repairing the failed pipe, joint or appliance itself.

Insurers commonly ask for evidence of the cause, location, repair and resulting damage. A clear report can prevent a claim from stalling because the insurer has insufficient information to assess it. Useful documentation normally includes the testing carried out, diagnostic findings, photographs, the exact source of the leak, recommended access, repair details and an engineer’s signed declaration where required.

Take photographs before moving furniture or removing damaged materials, provided it is safe to do so. Keep invoices and record when you first noticed the problem. If water is near electrics, isolated electrical circuits, or coming through a ceiling, treat it as urgent and seek professional help immediately.

For leasehold flats, also establish whether the affected pipework belongs to your flat, a neighbouring property or the building’s communal system. Your managing agent or freeholder may need to be involved, especially where water has travelled between homes. A specialist report can help establish the likely route and responsibility, although liability is ultimately a matter for the relevant parties and insurers.

What to do before the engineer arrives

If you can safely identify the affected supply, turn off the local isolation valve or the internal stopcock. If water is coming through a light fitting, avoid touching it and arrange urgent electrical advice alongside the plumbing response. Move valuables away from the area, catch drips where practical and avoid repeatedly repressurising a heating system if its pressure continues to fall.

Do not remove ceilings, lift large areas of flooring or strip bathroom tiles without evidence of the leak location unless there is an immediate safety reason. Early, uncontrolled damage often makes reinstatement harder and can complicate an insurance claim.

When you call, describe the symptoms rather than trying to diagnose the fault yourself. Mention whether the water meter is moving, whether the boiler pressure drops, when the damp first appeared, whether upstairs plumbing has been used, and any recent building work. These details help the engineer choose the right equipment and allow a more focused first visit.

Choosing the right person to fix a leak

For an exposed, straightforward plumbing fault, a qualified plumber is usually enough. For a concealed leak, repeated pressure loss, unexplained damp or an insurance-sensitive escape of water, choose a specialist with trace & access capability and a clear reporting process.

Ignite Plumbing Heating & Gas Ltd combines non-invasive leak detection with targeted repair and insurer-ready documentation, helping homeowners, landlords and property managers avoid the cost of unnecessary exploratory work.

The best repair starts with certainty. Acting early, preserving the evidence and using the right specialist gives you the strongest chance of stopping the water before a small hidden fault becomes a major restoration job.