Damp patches, ceiling stains, a musty smell, a hiss of running water with every tap off, or boiler pressure that keeps dropping — any of these can mean water is escaping somewhere out of sight. The quick test: turn everything off and close the stopcock. If the patch stops growing or the hiss stops, the leak is on your own pipework. Water near electrics or a sagging ceiling? Keep the water off and call 020 4577 2888 now.
What are the signs of a hidden leak?
Hidden leaks rarely announce themselves — they accumulate. Watch for a damp patch on a wall or floor that doesn't dry out, a brown ring or stain spreading on a ceiling, a musty smell in one room that airing never shifts, or the faint hiss or trickle of running water when the house is silent and every tap is off. One more that surprises people: a sealed-system boiler that keeps losing pressure days after each top-up. That pattern usually means water is escaping from the heating pipework somewhere — often a slow weep at a valve or a joint under a floor — rather than a one-off glitch.
The TestHow do I check whether the leak is on my pipework?
Here's the honest version, no gadgets required. Turn off every tap and anything that draws water — washing machine, dishwasher, any garden hose. Then close the stopcock. Now watch and listen: if a damp patch stops growing, or the hissing sound stops, the water was coming from your own pipework, because you've just cut off its supply. If the patch keeps spreading with the stopcock shut, the water has another source — a roof, a gutter, condensation, or a neighbour's pipe — and that changes who you need.
Most homes in Northern Ireland are unmetered, so the stopcock test is usually the whole story here. But if your home has a water meter, you can add a second layer: read it, use no water at all for 30 to 60 minutes, then read it again. If the numbers have moved with nothing running, water is leaving your supply somewhere.
When does a hidden leak become urgent?
Three situations shouldn't wait for a convenient appointment. Water anywhere near sockets, switches or the fuse board — keep clear, and switch off the electrics at the consumer unit if you can do so safely. A ceiling that is sagging or bulging, which means water is pooling above it and the plasterboard can give way. And a damp patch that is visibly spreading while you watch. In all three, shut the stopcock and call 020 4577 2888 straight away, whatever the hour. A slow, stable patch still needs fixing, but it can usually wait for daytime — which, as the costs guide explains, is normally the cheaper visit.
What will the plumber actually do?
Expect a search, not instant demolition. A good plumber narrows the leak down by isolating sections of pipework, checking the usual weep points — radiator valves, compression joints, the pipework around the bathroom — and building on what your stopcock test already proved. Tell them everything you observed: when the patch appeared, whether the hiss stopped with the stopcock shut, how fast the boiler loses pressure. In a district like this, where housing runs from town-centre terraces to farmhouses with long pipe runs, that detail genuinely shortens the hunt — and the bill that comes with it.