How Much Does Leak Detection Cost in London? (2026 Guide)

Leak detection pricing confuses people because it prices a diagnosis, not a repair — you are paying for equipment, expertise and a precise answer. Here is how the market actually works, what drives the numbers, and how to compare quotes intelligently.

The shape of a fair price

London domestic leak detection is typically charged as a fixed fee per visit, agreed before attendance. A standard visit runs two to four hours and should include pressure testing across circuits, thermal imaging, acoustic survey and moisture mapping, with tracer gas deployed where the case needs it. Expect roughly £250–£450 for a standard domestic detection visit in London, with complex cases — multiple circuits, large properties, underground supply runs, pools — quoted higher. A written report, where needed for insurance, is sometimes included and sometimes a modest add-on.

Repairs are always separate. A trustworthy company quotes the repair after the leak is found, when the scope is known — not as a bundled guess beforehand.

What moves the price up or down

• Property size and complexity — more circuits and more floor area mean more testing time.
• System type — a single combi circuit is quicker to survey than a house with UFH zones, a booster pump and a cylinder.
• Location of the leak — internal floors versus a 20-metre buried supply run under a driveway.
• Urgency — same-day and out-of-hours attendance carries a premium, quoted upfront.
• Reporting requirements — an insurer-grade report with moisture mapping takes real desk time after the visit.

What "no find, no fee" should mean

Taken honestly, it means: if a live leak is confirmed and the engineer cannot locate it, the detection fee is waived. Read the small print for the dishonest versions — fees that quietly convert to "survey charges" on failure, or "finds" defined so loosely that a damp reading counts. Ask directly: "under what circumstances would I pay you and still not know where my leak is?" A good company has a short, clear answer.

Three questions that expose a weak quote

1. "Which methods will you bring?" — one-instrument outfits find one-instrument leaks. You want acoustic, thermal and tracer gas on the van, used in sequence.
2. "Is the fee fixed before you attend?" — hourly open-ended diagnosis has a way of expanding.
3. "Will the report satisfy my insurer?" — if you may claim on trace and access cover, the report is half the value of the visit.

When someone else pays

Two routes commonly cover the cost:

• Trace and access insurance cover — most buildings policies pay the reasonable cost of locating a leak that is causing damage, plus making good the access. Our trace and access guide explains the claim sequence.
• Water company leak allowances — for supply pipe leaks, most London suppliers refund excess usage charges once the leak is evidenced as found and fixed promptly.

The real comparison: detection versus guessing

The alternative to paying for detection is exploratory work at builder day-rates plus reinstatement of everything opened in the wrong place — routinely several times the detection fee, before counting the extra weeks of water damage. Precision is the cheap option; it just invoices earlier.

Current fixed fees are on our pricing page, and every visit is covered by no find, no fee.