Emergency Plumbing & Boiler Repair · Mitcham, London
Leak Detection & Repair in Mitcham, London
A brown stain is spreading across the ceiling, but the bathroom above is dry. A meter dial keeps creeping with every tap shut, or the water bill has jumped without a reason. These are the signs of a hidden leak, and the expensive mistake is lifting floorboards and cutting walls at random. Emergency Plumber and Boiler Repair arranges leak detection and repair across Mitcham, matching you with a partner who finds the leak before anyone opens a wall.
Water takes the path of least resistance, so the point where it appears is rarely where it escapes. A pinhole in a copper pipe under a floor can soak a joist two metres away before it shows as a damp patch, and a leaking heating pipe shows as a falling boiler pressure rather than a wet wall. The partner starts with where, when and how the symptoms show, then confirms with tools.
The usual methods are a moisture meter and thermal imaging camera to map damp and temperature differences, acoustic listening equipment to hear water escaping under pressure, tracer gas on difficult cases and a pressure test of the pipework to prove which circuit is losing. A water meter check, with every tap off and the meter watched, tells you quickly whether the supply is leaking at all.
Published UK 2026 guides give a wide range, from about £75 to £300 for a basic check up to around £600 to £750 for a full domestic investigation with equipment, and complex cases near £1,000, while tracing a concealed leak is often quoted at £200 to £600. Repair is extra, and the partner's written quote is the only figure that counts.
Mitcham's housing gives leaks plenty of places to hide. Victorian and Edwardian terraces, many converted to flats in nearby Colliers Wood, share pipework and walls with neighbours, so a leak can originate in the flat above or next door, while 1930s semis and 1960s estates have pipes buried in screeds and floors. Thames Water supplies the area and its 2024 report gives 262 mg/l hardness, which scales and corrodes fittings over time. Call 07897 016796.
What We Do
How Hidden Leaks Are Found Without Wrecking the House
A methodical search costs less than guesswork, and these are the steps in order.
Meter Test and Moisture Mapping
The first test is the meter: shut every tap and appliance and watch whether the dial still turns. If it does, the supply is leaking. A moisture meter and thermal camera then map damp and cold or warm spots across walls, ceilings and floors, narrowing the area before anything is opened.
Acoustic Listening and Pressure Tests
Sensitive microphones pick up the hiss of water escaping under pressure, even through floors, and the partner can pressure-test sections of pipe, isolating the cold supply, the hot supply and the heating to find which loses pressure. This separates a heating leak from a water leak, which matters for the repair.
Tracer Gas and Camera Inspection
Where listening is inconclusive, a harmless tracer gas is introduced into the pipe and detected where it escapes, and a small inspection camera can look inside voids and drains. Together these usually pin the leak to a small area, so the access hole is the size of a hand rather than a bath panel.
The Benefits
Repair, Making Good and Who Pays for What
Finding the leak is half the job, and it helps to know what comes next.
The Repair Itself
Once found, a leaking joint is remade, a pinhole section is replaced or a failed fitting swapped. The partner quotes in writing before the repair and will tell you if the pipe is likely to fail elsewhere, such as in corroded copper.
Drying Out and Making Good
Plasterboard, flooring and carpets may need drying or replacing. Plumbers repair the pipe and may arrange drying equipment, but redecorating is usually a separate trade and cost, so ask what is included before you agree.
Flats, Neighbours and Landlords
In a converted terrace or a block, the leak may start in a neighbour's flat or a shared pipe. A written record of the cause, with photographs, helps when you need the neighbour, the managing agent or the landlord to act.
Why Us
How We Match Leak Jobs to the Right Partner
Not every plumber has acoustic and thermal equipment, so we ask the right questions.
Equipment Where It Matters
We ask what you can see, where, and what the meter is doing, then match you with a partner who carries detection equipment where the leak is hidden, rather than one who will start lifting floors.
Written Quote Before Repair
The partner quotes in writing before they repair, and invoices you directly. We take no payment, and the partner's name is texted to you before they arrive.
One Number After the Fix
If the leak or stain returns, ring 07897 016796 and we chase it with the partner. Our terms of service page sets out where responsibility sits.
Check the Meter Yourself First
A water meter is the simplest leak detector in the house, and the test takes a few minutes.
- Turn off every tap and appliance, including the dishwasher, washing machine and any outside tap, and make sure nobody flushes a toilet.
- Read the meter, wait twenty minutes, and read it again. If the numbers move, water is escaping somewhere between the meter and the taps.
- Look at the small dial or triangle. Many meters have a tiny spinner that turns with the slightest flow, which shows a leak the main dial would take hours to reveal.
- Note the time and the readings. The partner will use them to judge how big the leak is and whether it is on the supply or inside the house.
Signs That Point to Where the Leak Might Be
Damp and Staining
Brown rings on a ceiling, bubbling paint, a skirting that is damp to touch or a musty smell in a cupboard each suggest water, but not necessarily directly above or beside the mark, because water travels.
Heating Pressure and Noise
A boiler that loses pressure, or a gurgling radiator, may point to a heating leak rather than a cold supply leak, and the repair route is different. The partner will pressure-test each circuit to find out which.
Floors and Warm Patches
A floor that feels warm underfoot in one place, or a patch of damp carpet with nothing above it, can mean a leaking pipe in the screed. Mention it on the call, because it tells the partner which equipment to bring.
Related jobs are split pipe repair when a pipe has split, blocked drain clearance when the leak is below ground, and the full services list.
Frequently Asked Questions
How can I tell if I have a hidden leak?
The classic signs are a rising water bill without a change in use, a meter that keeps turning when every tap is off, damp or discoloured patches on walls and ceilings, a musty smell, a boiler that keeps losing pressure, or the sound of running water when nothing is on. Check the meter first, because it tells you whether the supply pipe is leaking. Then ring 07897 016796 and describe what you see so we can match you with a partner.
How does a leak detection visit work?
The partner asks about symptoms, then checks the meter and maps damp with a moisture meter and thermal camera. They may listen for the leak with acoustic equipment, pressure-test sections of pipework and use tracer gas if the result is unclear. Once found, they explain the cause, quote in writing for the repair and tell you what making good will be needed. The aim is a small, accurate opening rather than a demolition.
How much does leak detection cost?
Published UK 2026 guides show a wide range: about £75 to £300 for a basic check, around £600 to £750 for a full domestic investigation using equipment, and complex cases up to about £1,000. Tracing a concealed leak is often quoted between £200 and £600. London is typically higher. The repair is extra, and the partner company's written quote is the only figure that counts.
Is the leak on my side or the water company's?
The supply pipe from the street to your property boundary is the water company's concern, while the pipe from the boundary into your home is generally yours. A meter test helps: if the meter turns with everything off, the leak is on the supply side, and the partner will tell you where it is. Thames Water supplies this area, and the partner can explain what to report to them.
Can a leak be inside a wall or under a floor?
Yes, and it often is. Copper pipes in screeds or behind plaster can corrode or fail at a joint, and the water follows the line of least resistance before it appears. Thermal imaging and acoustic equipment find the likely spot, and the partner makes a small opening. Hard water, such as Mitcham's, can speed up corrosion in older pipework, so one leak may be a sign of others.
Is my leak a plumbing leak or a roof or damp problem?
It can be hard to tell. A stain on a ceiling can come from a roof leak, a leaking bath or shower above, a heating pipe or condensation. The partner checks whether the damp changes with weather, with water use or with the heating, and uses a pressure test to prove whether a pipe is leaking. If the cause is a roof, they will say so rather than guess.
What should I do while waiting for someone to arrive?
If water is visibly escaping, turn off the water at the stopcock, open the cold taps to drain the pipes and switch off the electrics if water is near sockets or lights. Move valuables, take photographs of the damage and place a bucket under any drips. If the leak seems to be a heating pipe, turn off the boiler. Then call 07897 016796. Our emergency plumbing page has more.
My boiler keeps losing pressure. Could there be a hidden leak?
Yes, a heating pipe leak under a floor or behind a wall shows as falling boiler pressure rather than visible water. The partner pressure-tests the heating circuit, checks radiator valves and joints and may use thermal imaging to find the leak. Topping up repeatedly masks the problem and invites corrosion. Our central heating repair page covers what else can cause pressure loss.
Will the leak be repaired at the same visit?
Often, if the partner has the part and access, and where the leak is a simple joint or fitting. Concealed leaks may need an access hole, a part ordered or drying before closing up, and complicated jobs take more than one visit. The written quote tells you what will be done and when, and the partner will explain what is temporary and what is permanent.
Who does the work, and who do I pay?
An independently owned partner company finds and repairs the leak, quotes in writing before work and invoices you directly. We take no payment and send no invoices, and we text you the partner's name before they arrive. If the problem returns, ring 07897 016796 and we chase it. See the step-by-step process for the full explanation.
Hidden Leak? Find It Before It Spreads
Call 07897 016796 any hour and we will arrange the nearest partner for Mitcham, Colliers Wood, Tooting and Morden.
07897 016796