Leak Detection & Repair Services in London

That damp patch on the wall. The sound of water you can’t trace. A water bill that’s crept up for no obvious reason. These are not things to sit on.

Water leaks cause more damage the longer they go undetected — to your walls, your floors, your property’s structure, and your wallet. Catalyst Home Services provides professional leak detection and repair across London, using specialist equipment to find the source without tearing your property apart unnecessarily. Whether it’s a hidden pipe behind a wall in Islington or a mains supply issue in Hackney, we locate it accurately and sort it properly.

Call us on +44 7400 265421 or book a plumber online — same-day appointments are available.

Signs You May Have a Water Leak

Leaks are not always obvious. Most of the serious ones start quietly, hidden inside walls, under floors, or underground — and by the time you notice visible damage, the problem has usually been building for weeks.

Here are the most common signs worth acting on:

• Your water bill has gone up without explanation — a sudden or gradual rise in usage charges often points to a leak somewhere in your supply system.
• You can see damp patches or water stains on walls or ceilings — especially if they appear without a clear source like a recent spill or condensation.
• There is mould or mildew forming in an area that was previously dry — mould needs sustained moisture to grow, and persistent damp behind surfaces is a common cause.
• You can hear running water when no taps or appliances are on — this is one of the clearer signals that water is moving somewhere it shouldn’t be.
• Your water pressure has dropped noticeably — a loss of pressure at the tap can indicate a pipe has cracked or a joint has failed somewhere along the line.
• There are warm patches on the floor — if your underfloor heating is not on and part of the floor feels warm, it may point to a hot water pipe leaking beneath the surface.
• Tiles have cracked or the floor has lifted in a specific area — water escaping under tiles creates pressure that eventually breaks grout lines and shifts surfaces.
• Your water meter is moving when all outlets are shut off — turn off everything in the property and check your meter. If the dial is still turning, water is escaping somewhere.

If you are seeing two or more of these signs, it is worth getting a professional in rather than waiting.

Our Leak Detection Process

Finding a leak properly means using the right tools, not just guesswork. Catalyst Home Services follows a structured detection process that avoids unnecessary damage to your property while pinpointing the source with accuracy.

Step 1 — Initial Assessment A qualified engineer visits your property and asks targeted questions about where you have noticed symptoms, how long they have been present, and what your plumbing layout looks like. This shapes the detection approach before any equipment is used.

Step 2 — Water Meter Check & Pressure Testing We check your water meter to confirm active water loss, then carry out pressure tests on the relevant pipe runs. A significant pressure drop in a closed system tells us where the problem section is before we go further.

Step 3 — Acoustic Leak Detection Using specialist listening equipment, we pick up the sound signature that escaping water creates inside a pressurised pipe. This method works through concrete floors, walls, and ground surfaces — without opening anything up first.

Step 4 — Thermal Imaging (Where Required) For leaks involving hot water pipes or underfloor heating, thermal imaging cameras identify temperature changes that are invisible to the naked eye. A warm trace on a cold floor tells us exactly where the heat is escaping.

Step 5 — Targeted Repair Once the leak is precisely located, we open only what needs to be opened. This keeps disruption to a minimum and means you are not paying to reinstate large sections of flooring or plasterwork that did not need to be touched.

Types of Leaks We Detect & Repair

Leaks come from different sources and behave differently. Here is what we deal with regularly across London properties.

Hidden Leaks Behind Walls & Floors

These are the leaks that cause the most damage because they go unnoticed longest. Water seeps into the structure of your wall or subfloor, causing damp, mould, and in serious cases, structural weakening. We use acoustic detection and thermal imaging to locate these without speculative opening-up, and we carry out trace and access work that your insurer may cover under your home insurance policy.

Underground & Mains Pipe Leaks

A leak on the supply pipe between the street boundary and your property is your responsibility under UK Water Regulations — the section beneath the pavement belongs to the water authority, but from your boundary inward, it falls to you. We detect underground leaks using ground-level acoustic equipment and carry out excavation and repair with minimal disruption. If you are in an area like Camden where older mains infrastructure is common, this is more frequent than people expect.

Central Heating & Radiator Leaks

A boiler that keeps losing pressure, or a radiator that weeps at the valve or the body, points to a breach somewhere in your central heating circuit. These leaks are often slow and easy to dismiss — until the boiler starts locking out or the damp works into the floor. We trace the circuit, find the failure point, and repair it properly rather than just topping up the system.

Bathroom & Kitchen Leaks

Pipe joints under sinks, waste pipes behind baths, silicone seals that have aged and cracked — bathrooms and kitchens are high-moisture environments where small failures escalate quickly. A dripping waste joint under a kitchen unit can go unnoticed for months while it quietly damages the cabinet base and subfloor beneath it. We inspect and repair both the visible fixtures and the pipework behind them.

Commercial Property Leaks

A water leak in a commercial premises is a different kind of problem. It can mean shutting down part of your operation, dealing with insurance claims, and meeting compliance requirements around water damage and building standards. Catalyst Home Services works with businesses across London to detect and repair leaks with the speed and documentation that commercial situations require. Our Commercial Plumbing service covers larger and more complex sites.

Why Early Leak Detection Matters

A small leak left alone does not stay small. Water finds the path of least resistance — into wall cavities, through floor joists, under slab foundations. Over time this leads to structural timber decay, rising damp, mould that affects air quality, and in prolonged cases, subsidence where the ground beneath a foundation softens. Your water bills climb quietly in the background while the damage compounds. Many UK home insurance policies do cover trace and access costs — meaning the investigation to find a hidden leak may be claimable even if the repair itself is not. Getting a report from a qualified engineer early gives you documentation your insurer will accept and keeps your options open.

Why Choose Catalyst Home Services

Same-day availability across London. When you have an active leak, waiting three days for an appointment is not acceptable. We offer same-day bookings and a 24/7 emergency line for situations that cannot wait.

Qualified engineers, not labourers. Every engineer we send is trained in leak detection methodology and works to UK Water Regulations standards. You can check our licences and certifications before you book.

Non-invasive first, every time. We do not open walls or lift floors to go looking. We use acoustic and thermal equipment to pinpoint before we touch anything. Most leaks are found without any structural access at all.

Transparent pricing, no surprises. You get a clear quote before any work starts. No hidden call-out fees added after the fact, no vague hourly rates that balloon. See what our customers say on our reviews page.

London-wide coverage. We cover residential and commercial properties across London, including areas like Hackney, Islington, Camden, and surrounding boroughs. Check our full service areas to confirm we cover you.

Related Services You May Need

A leak is not always an isolated problem. Depending on what we find, the issue may connect to your wider plumbing system. These services are commonly needed alongside leak detection work:

• Burst Pipe Repair — for pipes that have already failed and need immediate replacement
• Water Pressure Issues — if low pressure at the tap turns out to be leak-related
• Pipe Replacement & Relining — where the pipe itself is the problem, not just a joint or fitting
• CCTV Drain Survey — useful when a drainage or sewer issue is suspected alongside the leak
• Emergency Plumbing — for active, urgent situations that need a plumber out now
• Boiler & Water Heater Service — if the leak is traced back to your heating system

Get Your Leak Found and Fixed Today

If you have noticed any of the signs above, the best move is a quick call or an online booking — not waiting to see if it gets worse. Catalyst Home Services offers same-day leak detection across London, with a 24/7 emergency line for urgent situations. Call us now on +44 7400 265421 or book a plumber online and we will confirm your appointment straight away.