247 Rapid Response
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Nitrogen tracer-gas regulator and gauges set up next to a bathroom sink during a leak-detection callout

Leak detection

Acoustic leak detection across London

Specialist acoustic leak detection as part of our 24/7 leak detection service. Same fixed pricing, same 30 to 60 minute target response, same 12-month guarantee.

30 to 60 min target response12-month guaranteeGas Safe Registered
30-60 MINResponse time
12 MOWorkmanship guarantee
FULLYInsured & accredited
24/7365 days a year

Pressurised water leaving a small hole in a copper or steel water pipe creates a distinctive sound, a hiss between roughly 200Hz and 4kHz, that travels along the pipework and through surrounding building materials. Trained operators using calibrated electronic listening equipment can detect this sound, isolate it from background noise, and locate the leak with remarkable precision.

Acoustic leak detection is particularly effective on metallic supply pipework, copper hot/cold lines, lead supply mains, steel risers, where the sound carries efficiently. We use SewerIn Aquaphon A200 ground microphones, Sebakmt T8 contact sensors and Vivax Metrotech correlators, equipment shared with Thames Water and other UK water authorities for mains-leak surveys.

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When We Use This

Where this service applies

  • ✅ Underground supply pipe leaks (lead, MDPE, copper)
  • ✅ Buried mains supply between Thames Water stop-tap and property
  • ✅ Hot & cold water leaks under solid screed floors
  • ✅ Sub-floor pipe failures in flats above living spaces
  • ✅ Riser leaks in mansion blocks and apartment buildings
  • ✅ Concealed leaks where thermal imaging is not conclusive (well-insulated walls)
  • ✅ Verification of suspected leak locations identified by other methods
  • ✅ Insurance trace-and-access claims
Our Process

How we deliver

No surprises, no upselling. The exact path every job follows.

  1. 1
    Pressure-test isolation
    Hot vs cold, ground floor vs upstairs, isolated to identify which circuit is leaking.
  2. 2
    Background noise survey
    Calibrate listening equipment to filter out road noise, pumps, refrigerators.
  3. 3
    Surface contact survey
    Listening stick on every accessible pipe, valve and connection.
  4. 4
    Ground microphone walk
    Where buried pipework is suspected, ground microphones used at 1m intervals.
  5. 5
    Correlation analysis
    For longer pipe runs, two synchronised sensors used to triangulate the leak source mathematically.
  6. 6
    Insurance-grade written report
    Located leak position marked on plan. Access cuts recommended.
Frequently Asked

Your questions answered

How does acoustic leak detection actually work?
A leaking pressurised water pipe creates a distinctive high-frequency sound that travels along the pipe and through surrounding materials. Trained operators use sensitive listening equipment to detect this sound, filter out ambient noise, and locate the leak by tracking the sound to its loudest point.
How accurate is acoustic leak detection?
On metallic pipework with reasonable operating pressure (1.5+ bar), acoustic detection is exceptional, typically pinpoints leaks to within 50,150mm. On plastic pipework (MDPE, PEX) it's less reliable because the plastic damps the sound. We combine with tracer gas in those cases.
Can acoustic detection find leaks in plastic pipes?
Less effectively than on metal pipework. Plastic damps acoustic signals. For PEX or MDPE supply pipes we recommend tracer gas as the primary method, with acoustic as secondary verification.
How long does an acoustic leak survey take?
Typical residential survey: 60,90 minutes. Underground supply line surveys: 90,180 minutes depending on pipe length and access.
Will acoustic detection find a slow drip?
Slow drips at low system pressure generate weaker acoustic signal. We may need to artificially pressurise the system or combine acoustic with tracer gas to find very slow leaks.
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Need a 24/7 emergency engineer?

30 to 60 minute response across every London borough. Gas Safe registered. 12-month workmanship guarantee.

FAQ

Acoustic leak detection: your questions

How fast can you reach me for acoustic leak detection?
Typical on-site time is 30 to 60 minutes across the M25, subject to engineer availability and traffic. Live dispatch, never queued. Times quoted are best-effort targets, not contractual guarantees.
What does acoustic leak detection typically cost?
Labour is one flat rate across London and the M25, billed per 30 minutes: from £75 / 30 min (daytime) up to £147 / 30 min (nighttime), with a one-hour minimum then 30-minute increments. There is no callout fee. Domestic prices shown inc VAT, no hidden extras. Fixed-price conversion available on most jobs after diagnosis. Full rate card.
Is the work guaranteed?
Yes. Acoustic leak detection carries the same 12-month workmanship guarantee as every other leak detection job we do.
Are you Gas Safe registered?
Yes. Gas Safe Register number 972173. Verifiable live at gassaferegister.co.uk before our engineer walks in.

Need acoustic leak detection now?

30 to 60 minute response across every London borough. Gas Safe registered. 12-month workmanship guarantee.