Leak detection across London
A damp patch that comes back however many coats of paint go over it. A ceiling stain that grows a little every week. A water bill that keeps rising while nobody can say why. Whichever one you have, the source needs finding before any repair, or you end up paying to treat a symptom and not the leak itself.
- Fully insured and Gas Safe registered
- Engineers DBS-checked
- 24/7 emergency callouts
- Price agreed before we start
- Workmanship guaranteed
Monday – Sunday, 7:00 AM – 10:00 PM · Out-of-hours emergency? Call 020 3576 5825
Get a price for leak detection
Name, phone and postcode are all we need to start. Everything else can wait.
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Expect a call back on the number you entered. For anything urgent, there is no need to wait: ring 020 3576 5825.
Included in the job
- Concealed leaks in pipes behind walls and under floors
- Investigating damp and water damage
- Water use that has risen for no clear reason
- Leaks beneath tiled and solid floors
- Heating systems that keep losing pressure
- Checks before buying or refurbishing a property
Read this before you ring
You may find you can sort some of this yourself, without calling us. We are fine with that, and would rather you knew it.
Check the meter
Switch off all taps and appliances and note the reading on your water meter. Leave everything off for an hour, then read it again. Any movement means water is escaping somewhere on your supply. This single check tells us a lot before we even arrive.
Boiler pressure that keeps falling
If the boiler needs refilling every few weeks, the heating circuit is usually leaking somewhere, often through a pinhole in a pipe below the floor. It is worth tracking down, because each refill lets corrosion work on the system from the inside.
The leak is seldom right above the stain
Water often travels a fair way along a joist or beneath a floor before it appears. So the mark on your ceiling may sit some distance from the pipe that has actually failed. That is why Ninja Plumbers pinpoints the leak first, instead of cutting holes on a hunch and hoping one of them lands in the right spot.
Ring your insurer before booking
Plenty of home insurance policies include trace and access, which pays for locating the leak and for the making good that follows. It is worth checking before you book, and we can supply a report if your insurer asks for one.
What changes the price
You are paying for the search, and the repair is priced separately once the leak is found. How long the search takes depends on the building, the pipework involved and how much the leak is giving away.
Which system is leaking
The heating circuit, the mains cold supply, the hot water and the waste pipes are each tested in a different way. Isolating and pressure-testing them one at a time narrows things down when the culprit is not obvious, but every extra system adds time.
What the floor is made of
Pipes under a suspended timber floor are relatively easy to listen to and reach. Pipes buried in a concrete screed, tangled up with underfloor heating or beneath large stone tiles make the signal harder to read and the search slower.
A steady leak or an occasional one
A leak that runs all the time shows up clearly when the pipework is pressure-tested. One that only appears when the shower is on, or when the heating is hot, has to be recreated during the visit before it can be traced.
Inside the house or under the garden
If the meter test shows a loss but nothing inside is wet, the leak may be on the supply pipe under the front garden or path. Tracing along a buried external pipe is a different search, and usually a longer one.
We agree the price with you before any work begins, and accept both card and cash.
Questions we often get
Does my floor have to come up?
Finding the leak is non-invasive. After it is pinpointed, the repair may need access at that single spot, but that is one targeted opening, not exploratory work across the whole room.
How precise is leak detection?
Acoustic and thermal equipment normally narrows a leak down to a small area. No method is perfect through solid concrete, and if a site is tricky we will say so honestly instead of overpromising.
Could a doubled water bill mean a leak?
Often, yes, particularly if the way you use water has not changed at all. Do the meter test above first and tell us the result when you ring. It makes the visit quicker.
Can I get a report for my insurance claim?
Yes. Let us know when you book that you need one, and the engineer will record the job properly during the visit.
Should I turn the water or heating off before you arrive?
Only if the leak is actively causing damage. Otherwise leave things running normally, because a leak that is still behaving as it usually does is far easier to trace. If you have already turned the stopcock off or let the boiler pressure drop, that is fine — just tell us when you book, so the engineer knows to repressurise the system before starting the tests.
Can you repair the leak on the same visit?
Sometimes. If the leak turns out to be in reach — under a floorboard, behind a bath panel, at a valve — and the engineer has what is needed, the repair can often follow straight on, once you have agreed the price for it. If it is buried in a screed floor or behind tiling, the repair usually needs planning, materials and sometimes other trades, so it becomes a separate booking.
Leak Detection in your area
Pages for the parts of London where we are asked for this most often.
Appliance jobs linked to this service
Each of these installations falls under this service, with a page of its own explaining the work.
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Water Meter Installation
Plumbing work for a switch to a meter, including the shared supplies that hold it up.
Read about water meter installation
Other plumbing jobs we do
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Emergency Plumbing
For burst pipes, serious leaks or a house with no water. The phone is answered at any hour and an engineer is sent out.
Read about Emergency Plumbing -
General Plumbing
Radiators, pipework, taps and toilets: the small jobs that keep getting put off.
Read about General Plumbing -
Leaking Ceiling
Water dripping or pouring through a ceiling. What to do first, then the source found and stopped — in your home or the flat above.
Read about Leaking Ceiling -
Leak Repair
Leaks you can see — dripping joints, weeping valves, perished hoses, overflows running outside — isolated, repaired and checked properly afterwards.
Read about Leak Repair -
Toilet Repair
Toilets that will not flush, keep running, fill slowly or leak onto the floor. Usually one worn part, replaced without needing a new toilet.
Read about Toilet Repair -
Tap Repair and Replacement
Dripping, stiff and leaking taps repaired, and tired ones swapped for new.
Read about Tap Repair and Replacement -
Pipe Repair
Burst, split, frozen and corroded pipework repaired — or replaced where patching it would be pointless.
Read about Pipe Repair -
Low Water Pressure
Weak taps and showers diagnosed by testing, not by swapping parts and hoping.
Read about Low Water Pressure -
Lead Pipe Replacement
Old lead supply pipes replaced with new, from the boundary into the house.
Read about Lead Pipe Replacement -
Commercial Plumbing
Plumbing for offices, restaurants, shops and blocks of flats, timed to fit the hours you open.
Read about Commercial Plumbing -
Gas Safety Certificates
Your landlord gas safety certificate, checked and issued by a Gas Safe registered engineer and emailed over the same day.
Read about Gas Safety Certificates -
TMV Servicing & Testing
Thermostatic mixing valves tested, cleaned and reset, with a record for every valve, for schools, nurseries, care and business premises.
Read about TMV Servicing & Testing
Businesses use us for leak detection too, among them offices, blocks of flats and managing agents, launderettes and dry cleaners, garden centres and farm shops, pharmacies, estate agents, and plenty of other business types.
Leak or damp? A slow leak can look just like damp, and damp can pass for a leak. Read damp survey & diagnosis, penetrating damp & damp proofing and condensation control & ventilation, or go to our damp and condensation page.
Looking for leak detection in London?
Tell us what is wrong and where you are, and you will have the price before any work begins.