Gas Safe 919881 · Bromley
Water leak detection in Bromley
Falling boiler pressure, a water bill that has doubled for no reason, or a damp patch that keeps coming back. We trace the leak with thermal imaging, acoustic equipment and tracer gas before anything gets lifted, then repair it and put the system back into service.
- Heating leak survey
- £280, half day
- Insurance report
- Included, within 48 hours
- Method
- Non-invasive first, always
- Gas Safe
- Registration 919881
Get a free quote
Tell us what you need and we’ll come back to you with a price — usually within the hour.
Cost
What it costs
Most hidden leaks in Bromley are found the expensive way: a floor comes up, then another, until somebody guesses right. There is no need for that. A leak on a heating circuit, a mains supply pipe or a concealed bathroom run leaves a heat signature, an acoustic signature and a moisture gradient, and all three can be read through a floor. This page explains how we find yours, what it costs, and what your insurer will actually pay toward it.
| Job | Price | What it involves |
|---|---|---|
| Central heating leak survey | £280 | Half a day on site. Pressure test on the sealed system, thermal imaging across the floor area, acoustic tracing and moisture mapping. Covers a standard three or four bedroom house. Written report included. |
| Full-day tracer gas investigation | from £480 | Where imaging and acoustics cannot separate the source, typically microbore cast into screed or a slab wet long enough to have lost its temperature gradient. The circuit is drained, charged with 5% hydrogen in nitrogen and swept with a probe. |
| Mains water supply pipe trace | £320 | Boundary stopcock to internal stop tap. Meter drop test, ground microphone survey and pipe tracing to mark the run and the leak position on the ground before anybody digs. |
| Bathroom, shower or wet room leak trace | £240 | Ceiling staining below a bathroom, or a tray that only leaks in use. Moisture survey, controlled flood testing of tray, waste and seals, and thermal imaging of the wall and ceiling void. |
| Underfloor heating leak trace | from £420 | Manifold isolation to identify the failing loop, then thermal imaging to plot the run and pinpoint the breach. Repairing one loop in screed beats replacing a floor, and it is usually possible. |
| Repair after detection - accessible pipework | from £180 | A joint, a corroded section or a failed compression fitting reached through a floor void, ceiling or cupboard. Includes draining down, the repair and refilling. |
| Screed cut, repair and reinstatement | from £420 | An opening of roughly 300mm square over the marked position, the repair made in copper with no joint left buried where it can be avoided, screed made good ready for your floor finish. |
| Refill, re-pressurise and recommission | £110 | Inhibitor dosed, system vented and balanced, expansion vessel charge checked, boiler run up and flue gas analysis carried out. Gas work, included in our repair pricing rather than handed on. |
| Standalone trace and access report | £60 | Charged only for a re-issue for a loss adjuster, or a report on a detection carried out by somebody else. Included free with any survey we do. |
What changes the price
What the floor is made of
The single biggest variable. A leak under a suspended timber floor in a Beckenham terrace is found acoustically in under an hour and repaired through a lifted board. The same leak in microbore cast into a 1970s Petts Wood screed needs tracer gas to pinpoint and a screed cut to reach. Three times the cost, same fault.
How long it has been leaking
Thermal imaging works on the temperature difference between escaping water and the material around it. A slab quietly wet for eighteen months has equalised and gives a much weaker picture, which pushes the job toward tracer gas. Early is cheaper, which is the honest reason not to keep topping the boiler up.
How many circuits there are
One boiler and eight radiators on a single circuit narrows down quickly. A heating circuit, an underfloor manifold, a cylinder and an outside tap off the same run takes longer, because each section is isolated and re-tested in turn.
Access to the position
A fitted kitchen, a tiled bathroom or built-in wardrobes over the marked spot change the access cost, not the detection cost. We mark the position before anything is disturbed, so you can decide how to reach it and often claim that cost from your insurer.
Conservation areas and original floors
An original parquet, a Minton tiled hall or a listed interior is not something we cut through on a hunch. Where the fabric is protected the survey has to be precise enough to justify one small opening in the right place, and sometimes to justify an alternative pipe route instead.
Whether the repair is ours
A detection-only firm finds it, invoices and leaves you to find a plumber who charges a fresh call-out to drain the system down again. We price detection, repair, reinstatement and recommissioning as one job, which usually lands £200 to £300 below the same work split across two trades.
The question nobody answers
Your floor decides the method, and Bromley has three of them
Google’s own summary for "central heating leak detection" ends by asking the reader whether they have solid concrete or suspended timber floors, and then stops. It is the right question and it is most of the job. The borough divides almost exactly into three construction types, and each leaks differently, sounds different and has to be approached in a different order. This is the table we work from before we arrive.
| Build type and where it is | First method | Why that one |
|---|---|---|
| 1930s solid ground floor - Hayes, West Wickham, Bromley Common, Coney Hall | Tracer gas | Heating pipe run in or under the concrete slab when the house was later centrally heated. Concrete conducts heat sideways, so thermal imaging gives a broad warm smear rather than a point. Hydrogen and nitrogen migrates up through the slab and gives a position to within a few centimetres. |
| Microbore in screed, 1960s-80s - Petts Wood, Bickley, Park Langley, Crofton | Thermal imaging | 8mm and 10mm microbore laid in a screed topping over a slab. The screed is thin enough to show a genuine thermal trace of the pipe run, so the loops are plotted first and the leak read as the break in the pattern. Tracer gas confirms before anything is cut. |
| Suspended timber, Victorian and Edwardian - Beckenham, Penge, Anerley, Sydenham | Acoustic | A floor void carries sound well, and a pressurised leak on copper or old lead is audible through a ground microphone long before it shows anywhere. The cheapest build to work on, and the repair is usually through one lifted board. |
| Underfloor heating in screed - newer extensions and refurbishments borough-wide | Manifold isolation, then thermal | Each loop is isolated at the manifold and pressure tested individually until the failing circuit shows itself. Thermal imaging then plots that single loop and finds the breach, so one loop is cut and repaired rather than a floor replaced. |
| Buried mains supply pipe - every area, boundary stopcock to stop tap | Meter drop test and ground microphone | The meter is read with everything inside closed to prove the leak is on the supply, then the run is traced and surveyed acoustically along its length. Plastic MDPE is quieter than the lead or iron it replaced, which is where correlating between two points earns its keep. |
| Post-war estate housing - Downham, Mottingham, St Paul’s Cray | Pipe tracing, then acoustic | Pipework has usually been altered two or three times and rarely follows the drawings. We trace the actual run first with a signal generator and locator, because searching along a route the pipe does not take is how a day gets wasted. |
| Concealed pipe in a wall - flats and 1980s conversions borough-wide | Moisture mapping with thermal | A pinhole behind plasterboard or in a chased channel gives a moisture gradient that reads clearly on a meter, and thermal separates a cold mains run from a hot flow pipe, so we know which service has failed before opening the wall. |
Thermal imaging
A radiometric camera reads surface temperature to a fraction of a degree. On a heating leak the escaping water is hotter than the floor around it and shows as a plume; on a cold mains leak it is the reverse, a cold shadow under a warm floor. It is fast and completely non-contact, so it goes first in almost every survey. Its limit is depth: below roughly 75mm of concrete the picture blurs, which is when we move to gas.
Acoustic tracing
Water escaping under pressure through a small breach makes a consistent broadband hiss. A ground microphone and contact probes let us listen at the floor surface, on radiator tails and along a pipe run, comparing amplitude between points to walk in on the source. On a suspended floor or a buried supply pipe this alone finds most leaks. It works poorly once the ground has saturated, because the water damps the sound.
Tracer gas
The system is drained and charged with a 5% hydrogen, 95% nitrogen mix, non-flammable at that dilution, non-toxic and the smallest molecule available to us. It migrates up through screed, concrete, tile grout and floorboards, where a hand-held probe picks it up. It is the only reliable answer on a saturated slab.
Moisture mapping and pipe tracing
Pin and pinless meters give the gradient that tells us which way the water is travelling, which stops a survey chasing a damp patch two metres from the breach. A signal generator and locator plots where the pipe genuinely runs, including alterations made during a 1980s conversion and never drawn anywhere.
Trace and access: what your insurer will actually pay, and what it will not
Almost every UK buildings policy includes trace and access cover under the escape of water section. It pays to find the leak and to get to it - the survey, the floor opening, the making good afterwards. It does not pay for the pipe repair itself, which counts as maintenance, and it does not pay for what the water damaged unless you also hold escape of water cover. Four things decide whether a claim settles cleanly. The sub-limit, typically £5,000 to £15,000, sits inside the policy rather than on top of it. Pre-authorisation: most insurers want a written quotation and their agreement before an engineer attends, so ring them before you ring us. The report has to itemise trace, access, repair and reinstatement as separate lines, with dated photographs, the method used, the leak position and the pipe size and material, because a loss adjuster cannot settle a lump sum. And the excess applies once to the escape of water claim rather than once per element, so splitting the work across invoices gains you nothing.
Local
Leak detection across Bromley, and who owns which pipe
Two things are genuinely local about a Bromley leak. The housing stock decides the method, and the whole borough is on Thames Water, whose rules about the supply pipe cost people money every year because nobody explains them.
The boundary stopcock, and the pipe you own
Thames Water owns the communication pipe from the main in the road to the boundary stopcock, usually a small metal cover in the pavement or just inside the gate. From that stopcock to the house the supply pipe is yours, including the length under your front garden and your drive. A leak on the water company side is repaired free. A leak on your side is your bill, and it is far the more common of the two.
The free repair scheme and the leak allowance
Thames Water runs a scheme that will repair or replace a leaking external supply pipe on domestic property at no charge, once, subject to their conditions and the state of the pipe. Separately, if you are metered and a burst has inflated a bill, you can apply for a leak allowance covering the water lost, normally on condition the leak was repaired promptly. Two things catch people out: the work generally has to be done by a WaterSafe or WIAPS approved contractor, and you need dated evidence of when the leak was found and fixed. That is what the report we leave you is for.
Conservation areas: non-invasive is not a preference
The borough has around 47 designated conservation areas, including five covering Petts Wood, plus Chislehurst, Keston Village, Keston Park, Farnborough Village, Farnborough Park, Shortlands, Bickley Park, Sundridge Avenue and Park Langley. In a listed property, cutting into historic fabric to reach a pipe needs consent before it happens rather than after. In a conservation area, excavating a front garden for a mains leak can need consent, and reinstatement in matching materials is a planning condition rather than a courtesy. An original parquet or a Minton tiled hall cannot be relaid once it has been lifted badly. That is why the survey has to be accurate enough to justify one small opening in the right place.
Falling boiler pressure in the interwar semis
Across Petts Wood, Crofton, Hayes and Coney Hall we see the same job repeatedly. A sealed system losing pressure over a week or two, no visible wet patch anywhere, and heating pipe run in the solid ground floor by whoever converted the house from a back boiler. The owner has been topping it up from the filling loop for months, which quietly floods the slab and dilutes the inhibitor until the rest of the system starts corroding as well. It is a tracer gas job and it is worth doing early.
Microbore and old lead in the terraces
Penge, Anerley, Beckenham and Sydenham terraces carry two recurring faults. Microbore in 8mm and 10mm, added in the 1970s and 1980s, which corrodes from the inside once the inhibitor has been let go and pinholes at the bends. And original lead or early copper supply pipe under a suspended floor, joined to plastic at some point with a fitting that was never right. The upside of both is access: a lifted board rather than a broken floor, and repairs that usually land under £300 all in.
Where we cover
Bromley BR1 and BR2, Beckenham BR3, West Wickham BR4, Petts Wood and Orpington BR5 and BR6, Chislehurst BR7, Swanley BR8, and the borough’s non-BR postcodes that most detection firms leave off their maps entirely: Mottingham SE9, Grove Park SE12, Crystal Palace SE19, Penge SE20, Sydenham SE26 and Biggin Hill TN16. Our workshop is on Hastings Rd, Bromley BR2 8NA.
The job
How it works
-
We establish there is a leak before we look for one
On a heating system that means isolating the boiler and pressure testing the circuit with a gauge, so we can separate an actual leak from a failed expansion vessel or a passing pressure relief valve. Both lose pressure and neither is a leak. On a mains supply it is a meter drop test with every internal outlet closed. Roughly one call in six turns out not to be a leak at all, and finding that out in twenty minutes is the cheapest visit we do.
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Non-invasive survey, nothing lifted
Thermal imaging across the floor area, acoustic tracing at the surface and on the pipework, moisture mapping to establish the gradient, and pipe tracing to plot where the run genuinely goes. Nothing is cut, drilled or removed at this stage, and in a listed or conservation area property nothing is going to be.
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Tracer gas where the survey cannot settle it
If the picture is ambiguous - a saturated slab, deep microbore, or a leak that has run long enough to lose its temperature difference - the circuit is drained, charged with hydrogen and nitrogen and swept with a probe. We would rather spend the extra two hours than mark a position we are not certain about and open somebody’s floor on it.
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Mark it, price it, then repair it
The position is marked on the floor and photographed. You get the repair and reinstatement price before anything is opened, along with the report if you are claiming. Where the pipe is reachable through a void we repair the same day; where a screed cut is needed we agree the opening size first.
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Refill, recommission and sign the gas work off
A heating repair is not finished when the pipe stops leaking. The system is refilled, dosed with inhibitor, vented and balanced, the expansion vessel charge is checked, and the boiler is run up and checked with a flue gas analyser. That last part is gas work under our Gas Safe registration, 919881, and it is the step a detection-only firm cannot carry out.
Included
What comes as standard
- Pressure or meter drop test first, to confirm there is genuinely a leak
- Thermal imaging survey with a radiometric camera
- Acoustic tracing with ground microphone and contact probes
- Moisture mapping and pipe route tracing
- Tracer gas where the non-invasive survey cannot settle the position
- Leak position marked on site and photographed before anything is opened
- Written report within 48 hours, itemised as trace, access, repair and reinstatement
- Repair, refill, inhibitor dose and rebalance carried out by the same engineers
- Boiler recommissioned and flue gas analysis carried out under Gas Safe registration 919881
- Second visit at no charge where an intermittent leak is not located first time
- 12-month guarantee on our workmanship
Questions
Leak detection questions
How much does leak detection cost in the UK?
You will find two very different answers and neither side explains the other. Checkatrade quotes Bromley searchers £160-£348, average £234. The leak detection specialists ranking for the same search publish £495-£595 plus VAT, because they price a full day with a dedicated detection engineer. Both are honest for the work each describes. Ours sit between them because we are heating engineers with the same equipment rather than a separate call-out: £280 for a half-day heating leak survey, £320 to trace a mains supply pipe, £240 for a bathroom or shower leak, from £480 where a full day of tracer gas is needed. The repair is quoted separately, before it happens.
Does home insurance cover leak detection?
Usually, through trace and access cover in the escape of water section of a buildings policy. It pays to find the leak and to get to it, including the floor opening and making good afterwards, normally up to a sub-limit of £5,000 to £15,000. It does not pay to repair the pipe, which counts as maintenance, and it does not cover your belongings unless you hold contents cover too. Two practical points: most insurers want a written quotation and their authorisation before an engineer attends, so call them first if you intend to claim, and the excess applies once to the claim rather than once per element.
My boiler pressure keeps dropping. Is it a leak?
Not necessarily, and the two cheaper causes are worth ruling out first. A failed expansion vessel loses pressure as the system heats and cools, and can be diagnosed in ten minutes with a gauge. A pressure relief valve left passing after a service drips from the discharge pipe outside, so look at the wall below it on a cold morning. If both check out and the system is losing more than about 0.2 bar a week with no visible wet patch, you have a leak, and in Bromley it is most often on a pipe run in or under the floor. Do not keep topping it up for months: fresh water brings fresh oxygen, dilutes the inhibitor and corrodes the rest of the system while you wait.
How can I find a central heating leak under the floor?
Not by lifting floors, which is what usually happens. The reliable sequence is to pressure test the circuit isolated from the boiler; run a thermal camera across the floor for the warm plume where escaping water is heating the covering; listen acoustically at the surface and on radiator tails for the hiss of water under pressure; and where the floor is solid concrete, or the leak has equalised, drain the circuit and charge it with hydrogen and nitrogen, which migrates up through screed and grout to give a position within a few centimetres. Which comes first depends entirely on whether the floor is suspended timber, screed over slab, or solid concrete.
Will you have to lift my floor to find the leak?
No. The survey is non-invasive throughout, and nothing is cut, drilled or lifted until we have marked a position and you have agreed the price of reaching it. That matters most in the borough’s conservation areas and listed properties, where an original parquet, a Minton tiled hall or protected fabric cannot simply be taken up and put back. There the detection has to be accurate enough to justify a single small opening, and where consent would be needed to cut into historic fabric we will say so before anything starts.
If there is a water leak outside my house, who is responsible?
It depends which side of the boundary stopcock it is on. Thames Water owns the pipe from the main in the road to that stopcock, normally under a small cover in the pavement or just inside your gate, and repairs leaks on it free. From the stopcock to the house the supply pipe belongs to you, including the length under your front garden and drive, and that is where most external leaks are. Thames Water does run a scheme that will repair or replace a leaking domestic external supply pipe at no charge, once, subject to their conditions, so report it before paying for the work. If you are metered and a burst has inflated a bill, you can also apply for a leak allowance for the water lost, provided the repair was prompt and you can evidence the dates.
What happens if you cannot find the leak?
You will know the answer before you book, which is more than most firms in this market will tell you. If the survey does not locate the leak on the first visit and the fault is intermittent, such as a shower tray that only leaks in use or a joint that weeps only at temperature, we come back and continue at no further charge. If the pressure test shows no leak at all, and it is a vessel or a relief valve instead, we say so and charge for the diagnosis rather than a full survey.
Do you repair the leak as well as find it?
Yes, and it is the main reason to use a heating firm rather than a detection-only contractor. The specialists ranking for this search find the leak, issue a report and leave, and several state openly that they do not repair. You then pay a plumber a fresh call-out to drain the system again. We do detection, repair, screed reinstatement, refill and inhibitor dose and boiler recommissioning as one job. Draining and recommissioning a sealed system is gas work, carried out under Gas Safe registration 919881.
Do central heating leak sealers work?
On a genuine pinhole in a system that is otherwise sound a sealer can hold, and it is a reasonable stopgap in January when the alternative is a week without heating. It is not a repair. Sealers deposit solids where water is escaping, which means they also deposit where you do not want them: the heat exchanger, the pump, and microbore, which is exactly the pipework most likely to be leaking. Several manufacturers decline a warranty claim on a heat exchanger that has had sealer through it. If a leak is bad enough to need sealer, it is bad enough to be found.
How long does leak detection take?
A central heating survey on a typical Bromley three or four bedroom house is half a day, and most leaks on suspended timber floors are located inside the first hour. A mains supply trace from the boundary stopcock is two to three hours including the meter test. Where tracer gas is needed it becomes a full day, because the circuit has to be drained, charged and swept methodically. The report follows within 48 hours. If you are claiming, allow for the time your insurer takes to authorise, which is usually the longest part of the process.
Who pays to put the floor back after the leak is repaired?
A screed opening of roughly 300mm square over the marked position, the repair made in copper and the screed made good ready for your floor finish runs from £420 with us. Drying is the part people underestimate: a saturated slab needs several weeks to reach a normal moisture content, and a new covering laid before it has dried will lift. Where a claim is running, the opening and the reinstatement are what trace and access cover pays for, while the pipe repair is yours. We itemise the invoice on those lines so the split is obvious to a loss adjuster.
Do you detect swimming pool, roof or drainage leaks?
No. We are heating engineers and plumbers, so we cover domestic water: central heating circuits, mains supply pipes, hot and cold runs, underfloor heating, bathrooms, showers and concealed pipework. Pool detection needs divers, a roof leak needs a roofer and drainage needs a CCTV survey, and we would rather say so than take the booking and subcontract it at a margin. If the water turns out to be coming from something outside what we do, we tell you on the day and you are not charged for a full investigation.
Coverage
Where we work
Across the London Borough of Bromley — BR1 to BR7 — plus Penge, Sydenham and Crystal Palace.
No heating? No hot water?
Get a fixed price from a Gas Safe registered engineer — not an answering service. Same-day appointments across Bromley most days.