Claims Evidence
Central Heating Leak Detection London
A sealed system that keeps dropping pressure feels like a leak and very often is not. A tired expansion vessel or a pressure relief valve that is passing produces the same falling gauge, and neither is an escape of water. If nobody settles that first, a claim can be opened on a premise that was never true, which is harder to unwind than it is to avoid.
How a heating survey reads on a claim file
| Invoice line | How it is treated | When it is settled |
|---|---|---|
| Eliminating the vessel and relief valve | Establishes whether an insured event exists at all | First hour, before circuit work |
| Per circuit isolation and pressure testing | Detection line, recorded circuit by circuit | Fixed fee agreed at booking |
| Locating the losing circuit under floor | Detection line, method attributed to each finding | Same visit where the circuit is reachable |
| Opening up over the confirmed run | Access line, held to what was known at the time | Quoted once the run is narrowed |
| Refilling, balancing and inhibitor | Maintenance, routinely excluded from a claim | After the repair line is closed |
Fee basis, not a quote, and not a statement of what your own policy covers. Our detection figure is fixed and confirmed in writing before anyone travels.
So the vessel charge and the relief valve are eliminated before circuit work starts, and the readings are written down either way. If the answer is the boiler, you get that in writing with the numbers behind it and no claim needs troubling. If the answer is a genuine loss, the file starts with the one thing an adjuster would otherwise ask about.
From there each circuit is isolated and pressure tested on its own, with the results logged for the ones that held as well as the one that did not. Thermal under working load shows the buried run, and tracer gas takes it through screed to a point. What ends up on paper is a mechanism, a location and a list of what was cleared.
One fixed detection figure agreed before attendance, covering the component checks, the circuit testing, the survey and the written findings. Access, pipe repair, and refilling with inhibitor are quoted separately, the last as maintenance, because wordings routinely exclude it.
What you get
- Comprehensive 'Trace & Access' reporting for immediate insurer submission.
- Use of thermal imaging and acoustic listening to pinpoint leaks with minimal invasive probing.
- Documentation includes timestamped photos, moisture maps, and a clear cause-and-effect analysis.
- Focus on preserving evidence of the original leak source, crucial for claim validation.
- Detailed scope of works for the subsequent reinstatement, supporting repair cost estimates.
- Direct liaison with loss adjusters, providing technical clarification on our findings.
How it works
A method, not a guess
01
Rule on whether there is a loss at all
Expansion vessel charge and relief valve discharge checked and recorded first. A system losing pressure through its own components is not an insured event, and saying so plainly is more useful than surveying a building for water that never left it.
02
Test each circuit separately
Every heating circuit closed off and pressure tested alone, with the result logged whether it held or failed. The circuits that held are what allow the opening up to be confined to one area without an assessor wondering what else was never checked.
03
Image the system under load
Run up to working temperature so the buried flow and return show as a pattern, then compare the anomaly against moisture readings at stated points. A cold system hides the run and makes the imagery worthless.
04
Name the mechanism
Corrosion pinholing an older run reads differently from a compression joint that was never made up properly. Coverage turns on mechanism, so the report names it rather than reporting that a leak was found under a floor.
Six checks before you treat falling pressure as a leak
Has the expansion vessel been checked?
A vessel that has lost its charge is the single most common reason a sealed system keeps dropping pressure, and it produces exactly the symptom a leak produces. Water is expelled through the pressure relief valve each time the system heats, the gauge falls, and nothing anywhere in the building is wet. It takes well under an hour to test. Until it has been tested, commissioning a survey of the property means potentially paying to look for water that never left the pipework, and opening a claim on a premise that was never true.
Is the relief valve discharge pipe wet outside?
The discharge from a pressure relief valve terminates outside, usually low on an external wall, and a valve that is passing will show as intermittent wetness or staining there. It is a thirty second check that anybody can do before making a phone call. A passing valve is a component fault rather than an escape of water, which matters a great deal for insurance purposes, because there is no insured event to claim for and a file opened on that footing has to be unwound later.
Was each circuit tested separately, with the results kept?
A heating system is several circuits sharing a boiler, and testing them as one thing throws away most of the diagnostic value. What should exist afterwards is a record of each circuit isolated, pressure tested and logged, including every circuit that held. That record is what makes the decision to open one floor rather than another self evident to somebody reading the file cold. It is also unrecoverable once the visit has ended, and recreating it means paying for a second attendance.
Was the system hot when the imaging was done?
Thermal imaging of a heating system on a cold circuit shows very little, because the whole method depends on the buried flow and return being warmer than what surrounds them. The system should be run up to working temperature before the camera comes out, and the report should say that it was. Where a survey produced nothing and the report is silent about the conditions, it is impossible to tell afterwards whether the property is sound or whether the method was never given a chance to work.
Does the report name a mechanism or just a place?
Coverage turns on how something failed, not simply where. Corrosion pinholing a run that has been in the floor for thirty years reads differently from a compression fitting that was never properly made up, and both read differently from a nail driven through a pipe during a refit. A report saying a leak was found beneath the hall floor gives an insurer no way to apply the wording, so they ask, and the asking is the delay. Naming the mechanism is what makes a file capable of being decided.
Are the refill and inhibitor quoted separately?
Draining a circuit for testing means refilling it, rebalancing the system and dosing it with inhibitor afterwards. Those are maintenance, policies routinely exclude maintenance, and putting them inside a detection figure does not get them paid. What it does is give an insurer a reason to query the whole line, which holds up the part that would otherwise have been settled straight away. Ask for them as a separate item before the work starts, not as a surprise on the invoice.
Compare like for like
Pressure loss is not the same thing as an insured event
A sealed system dropping pressure feels like a leak and often is not. A tired expansion vessel or a weeping pressure relief valve produces exactly the same symptom, and neither is an escape of water. If a survey does not settle that question first, a claim can be opened on a premise that was never true.
| What to check | A one line invoice | A top up and go firm | Emergency Leak Detection 247 |
|---|---|---|---|
| Vessel and relief valve eliminated first | Not attempted. The system is topped up, the pressure falls again, and a fortnight has gone. | The topping up is the service. Nobody has established whether water is leaving the building at all. | The vessel charge and the relief valve discharge are checked before any circuit work, because if either is at fault there is no insured event and the file should say so. |
| Circuit by circuit testing | Not done. The system is treated as one thing, so the report cannot say which part failed. | Not done, and the pressure gauge is the only instrument in use. | Each circuit is isolated and pressure tested on its own, with the result logged whether it held or failed. |
| Thermal under working load | Not used. A cold system hides the run entirely. | Not used. | The system is run up so the buried flow and return show as a pattern, then the anomaly is checked against moisture readings before anything is concluded. |
| Under screed and under floor | Beyond what is offered. The advice is to lift and look. | Beyond what is offered. | Tracer gas carries through screed and tile to a surface point, which is what allows the opening up to stay small enough to justify. |
| Inhibitor and maintenance framing | Charged as part of the same figure as everything else, which pulls an excluded maintenance item into an insurance invoice. | Charged as the main item, which is honest about what it is but does not address the loss. | Refilling, balancing and inhibitor are stated as maintenance, separate from detection and separate from repair, because wordings exclude them and a mixed line delays the rest. |
| What the report concludes | That a leak was found or was not. Either way an adjuster has nothing to assess. | Nothing is written. The visit is a top up. | The mechanism of failure, its location referenced to something findable, what was eliminated and how, and an explicit statement of what could not be established. |
| If the answer is the boiler | You are invoiced for detection on a system that was never losing water. | You are invoiced repeatedly for top ups on a system that was never losing water. | We say so, in writing, with the vessel readings that show it. A documented no leak result is a legitimate outcome and stops a claim being built on the wrong premise. |
What claimants ask
The questions policyholders and agents ask most
Sealed system pressure discussions are among the most durable on the DIY discussions, and they follow a familiar course. Somebody has been topping up weekly for months, has had at least one contractor look for a leak, and is being quoted for detection. The regulars almost always ask the same question first, and it is not about the pipework.
Months of topping up before anyone checked the vessel
The classic thread. Pressure falls, the system gets repressurised, nothing is ever wet, and after several visits somebody finally tests the expansion vessel and finds it flat. The advice is now so well established on the discussions that posters are told to check it before anything else. Our take is identical, which is why the vessel and the relief valve are eliminated in the first hour rather than after a whole property survey has been paid for.
Wet patches outside that nobody connected to the boiler
Posts where staining on an external wall turned out to be the relief valve discharge, with the system quietly expelling water every time it heated. The reason it takes so long to spot is that the wetness is nowhere near the boiler. Our take is that it belongs on the checklist for every pressure loss enquiry, and we ask about it on the call, because a component fault is not an escape of water and the file should never have been opened as one.
Disputes about whether corrosion counts as a claim
A recurring insurance board argument. A pipe has failed through age and the policyholder expects the whole thing to be covered. The replies usually explain that the damage caused by a sudden escape is one question and the deteriorated pipe is another. Our take is to describe what was actually observed and let the wording be applied to it, since we are a detection and reporting contractor rather than advisers and we do not act for your insurer.
Detection quoted for a system that was never losing water
Threads where somebody paid for a leak search on a system whose only fault was inside the boiler casing. Regulars point out that the survey was the wrong purchase rather than a bad one. Our position is that a contractor quoting for whole property detection without first asking how the system behaves when it heats is guessing at your expense, and an hour of elimination at the start is the cheapest hour in the job.
Surprise charges for refilling and inhibitor
A smaller but very consistent complaint. A system is drained for testing, refilled, and an unexpected line appears on the invoice. The advice is to agree the recommissioning up front. We quote it separately and call it maintenance, which is less flattering than folding it in but keeps the detection line clean for whoever has to assess it.
Questions
Asked before every booking
The pressure drops every few days but nothing is wet. What is happening?
In a high proportion of these cases the water is leaving through the pressure relief valve discharge pipe outside, or the expansion vessel has lost its charge and the system is expelling water each time it heats. Both mimic a leak precisely and neither is an escape of water for insurance purposes. It takes under an hour to check both, and doing it first avoids paying for a whole property survey to find a fault that is inside the boiler casing.
Will my insurer cover a heating pipe leak under the floor?
Where a pipe has failed and caused damage, the damage generally falls under the escape of water section and the cost of finding and reaching the pipe generally falls under the trace and access extension, subject to its limit and your excess. The pipe itself is usually your own cost. What is routinely excluded is anything that reads as wear or maintenance, which is why the report describes what was actually observed and leaves the wording to be applied to it.
Why do you record circuits that passed the test?
Because that record is what a loss adjuster asks for when a claim is queried, and it is unrecoverable once we have left the property. If the file shows that four circuits were isolated and held and one failed, the decision to open a floor over the fifth is self evident. If the file mentions only the fifth, the obvious question is whether the others were ever tested, and answering that question three weeks later means a second visit.
Do I have to pay for refilling and inhibitor?
Yes, and we invoice it separately and describe it as maintenance for a reason. Draining and refilling a system, rebalancing it and dosing with inhibitor are routine servicing items that policies generally exclude. Folding them into a detection figure does not get them paid. It gets the detection figure questioned, and delays the part that would otherwise have been settled.
Can you find a leak without draining the system down?
Usually the location, yes. Circuit isolation and pressure testing narrow which loop is losing, and thermal under load will often show the run and the anomaly. Draining becomes necessary when tracer gas is the only method that will fix the point, typically under screed or where the run is long. We say at the outset if we expect to need it, so the visit and the refilling can be planned rather than sprung on you.
Why does my boiler pressure keep dropping?
There are three realistic explanations and only one of them is a leak. The expansion vessel may have lost its charge, so the system expels water through the relief valve every time it heats. The relief valve itself may be passing. Or a circuit has genuinely failed somewhere in the building. The first two are component faults inside or adjacent to the boiler and are not escapes of water, which is why they should be eliminated before any survey of the property is commissioned.
Can a heating leak be found without lifting the floor?
The location usually can. Isolating and pressure testing each circuit identifies which loop is losing and clears the ones that are not. Running the system up to temperature lets thermal imaging show the buried run and any anomaly along it, and that is checked against moisture readings at stated points. Where the floor is screeded, tracer gas carries up through the construction to a surface point. Something still has to be opened to repair the pipe, but it should be a small and evidenced opening.
Will my insurer cover a leaking heating pipe?
Typically the damage caused falls under the escape of water section with its own excess, and the cost of locating the failure and of opening up and making good to reach it falls under a trace and access extension with its own limit. The failed pipe itself is usually your own cost. What tends to be excluded is anything reading as wear, maintenance or gradual deterioration, and refilling with inhibitor sits squarely in that category, which is why we invoice it separately.
How long does a central heating leak survey take?
Most domestic systems are covered in a working day. Isolating and testing each circuit takes the first part of it, and the system then needs to be run up before imaging is worthwhile. Where tracer gas is required the circuit has to be drained and charged and the gas given time to travel, which extends things. Where a second visit is genuinely necessary we say so on the day rather than issuing a conclusion the testing does not support.
Is a small pressure drop always a problem?
Not necessarily. A slight fall over a long period can be normal, particularly after radiators have been bled or work has been done on the system. What is not normal is needing to repressurise weekly or more often, or a gauge that drops noticeably every time the heating runs. The second pattern points strongly at the expansion vessel or the relief valve rather than at the pipework, and that is where a sensible investigation starts.
What if the survey shows no leak at all?
You get that in writing with the vessel readings, the valve observations and the circuit test results that support it, which is a useful document rather than a disappointing one. It stops money being spent looking for water that never left the system, and it redirects the work to the boiler where it belongs. Where we attend a confirmed live loss and cannot locate it, the detection fee is waived and you keep the full record of what was tested.
London-wide
Covering all 33 boroughs
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