Home › Hidden Leaks
Nothing's obviously flooding, but something's not right. Let's go through the signs together, one at a time.
I think there's a leak somewhere but I can't see it — where do I start? Run the stopcock test: turn off every tap and appliance, note your water meter or boiler pressure gauge, wait twenty minutes without using any water, then check again. Movement with nothing running is a strong sign of a leak. If it confirms one, ring 020 4577 2888 and I'll come and trace it properly.
Damp patches, ceiling stains, a musty smell, and pressure that keeps quietly dropping. None of them shout, which is exactly why hidden leaks go unnoticed for so long.
A hidden leak rarely announces itself the way a burst pipe does — there's no dramatic flood, just a slow accumulation of small clues. A discoloured patch on a ceiling or wall that grows a little wider every month, a corner of carpet that never quite dries out, a faint musty smell in a room that shouldn't have one, or paint and plaster that's started to bubble slightly. Any one of these on its own might be nothing much; two or three together, in the same part of the house, is worth taking seriously.
Boiler pressure that keeps dropping, which I cover properly in the boiler guide, is one of the most reliable early warnings there is, because a sealed heating system losing pressure repeatedly is very often losing that water into your walls or floor rather than anywhere visible. If you're topping it up more than once every few months, that's the leak talking to you before the damp patch ever shows up.
Everything off, note the number, wait, check again. It's the single most useful thing you can do yourself before I arrive.
It's not a perfect test — some fixtures like a slow-filling toilet cistern can skew a meter reading if you're not careful to rule them out first — but it's the clearest home version of what I'd do with proper equipment, and it tells me a great deal before I've even arrived.
I'll usually start with acoustic listening equipment and thermal imaging before anything gets opened up. Finding the leak precisely means less disruption fixing it.
Before any wall or floor gets touched, I'd rather listen for it — a leak under mains pressure often has a distinct sound that specialist listening equipment can pick up through a floor or wall, and a thermal camera can spot the temperature difference a hidden water leak leaves behind, especially useful for a hot water pipe. Between the two, I can usually narrow a search down to a small area rather than guessing across a whole room.
In the older streets around Armagh's cathedrals, where houses often sit on solid floors with pipework chased into walls decades ago, that precision matters even more — opening up the wrong section of a period floor or a lath-and-plaster wall is its own kind of expensive. Getting the location right first is worth the extra time it takes.
Anything inside your home and its pipework is yours; the shared or public network beyond your boundary generally isn't. The same principle as a burst pipe or a blocked drain applies here.
The same boundary logic I'd apply to a burst pipe applies to a hidden leak: everything from your property boundary inward, including your own supply pipe once it's on your land, is yours to sort. A leak that seems to be tracking back towards the boundary, or showing up as a soggy patch of garden or footpath outside your walls, might be the responsibility of NI Water instead, and that's worth raising with them directly rather than paying for a repair that isn't yours to make.
If you're renting, the same general rule applies as everywhere else on this site — fixed pipework and heating are usually the landlord's responsibility to repair, though you're expected to report the problem promptly once you're aware of it. A quick word with your landlord or agent before booking anyone protects everyone involved.
More than most people expect — even a slow, barely visible drip running continuously adds up over weeks and months, both in wasted water and in the damage it does quietly to timber, plaster and flooring behind the scenes. It's rarely the leak itself that costs the most; it's the repair to everything it's been soaking unnoticed.
Not necessarily — it can just mean the leak is intermittent, tied to a specific appliance running, a shower being used, or heavy rain testing a different weak point entirely. An intermittent patch is often harder to trace precisely because it isn't always ready to be inspected when I arrive, so noting exactly when it appears helps enormously.
If you're on a meter, yes, and an unexplained rise in usage is often the first clue people notice before any visible damp shows up at all. Northern Ireland households are typically charged differently to the rest of the UK, but a meter or a sudden change in usage patterns is still worth checking against what you'd expect.
Yes, if it's easy to do safely — damp timber furniture, carpets and boxes stored nearby can all take on water and mould faster than you'd think. Just don't go pulling up flooring or opening walls yourself; leave the actual tracing and repair to me once I'm there.
The main page — how the line works and the areas it covers.
Go to home →The first five minutes, in the right order.
Walk through it →Pressure drops, no heat, error codes — and gas safety.
Walk through it →What to try yourself and when it's the sewer, not your drain.
Walk through it →Honest ballparks and the questions to ask before work starts.
Walk through it →Pressure, controls, the immersion — the checks before you call.
Walk through it →Thawing safely with gentle heat — and the lagging that prevents it.
Walk through it →Ring any hour and I'll put you through to a local plumber covering Armagh and the surrounding villages.
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