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The worst leaks aren't the dramatic ones — they're the quiet ones, weeping into a floor for months. Here's how to spot them, one honest test that narrows things down, and the moments it stops being a wait-and-see job.
The short version: damp patches, ceiling stains, a musty smell, a hiss of running water when everything's off, or boiler pressure that keeps dropping — any of those says water is going where it shouldn't. Close the stopcock and see if the signs stop getting worse; that tells you the leak is on your own pipework. Water near electrics or a sagging ceiling? Ring 020 4577 2888 now, any hour, to be put through to a local plumber.
A hidden leak announces itself sideways. A damp patch on a wall or ceiling that doesn't dry out. A tide-mark stain under the bathroom. A musty smell in one room that airing never shifts. Skirting or flooring that's swelling or lifting. A faint hiss or trickle when every tap and appliance is off — stand in the quiet hall at night and listen. And on sealed heating systems, the gauge tells tales: boiler pressure that keeps dropping means the system is losing water somewhere, even if no room shows it yet. In the older terraces around Dungannon town centre, where pipework of mixed ages has been patched and extended over decades, a tired joint under a floor can weep for a long time before anything shows — which is exactly why the odd damp patch is worth taking seriously early.
One honest experiment narrows it right down, and it costs nothing.
If the signs carry on with the stopcock closed, the water is coming from somewhere else — the mains side, next door, or rain finding a way in. That changes who you call, so the test is worth the hour it takes.
Because the sealed heating circuit is a closed loop, and a closed loop that keeps needing topped up is leaking — there's no third option. The escape route might be a weeping radiator valve you can see, or a joint under the floor you can't; either way the filling loop is feeding the leak, not fixing it. Top up once, note the date, and watch. Losing pressure over months is one conversation; losing it over days is a leak with its coat on. Heating-circuit water also stains ceilings a dirty brown when it finally surfaces, so a pressure gauge on the slide and a tea-coloured mark on the plaster are usually the same story told twice. Have it traced while it's still invisible — and as with every job on this site, ask for a price before any work starts.
Three signs move a hidden leak into ring-now territory. Water anywhere near sockets, light fittings or the consumer unit — cut the electrics at the consumer unit if you can reach it dry, and touch nothing electrical that's wet. A ceiling that's sagging or bulging — stay out from under it; a bellyful of water comes down all at once. And a patch that's spreading while you watch, which means the leak has stopped being slow. In all three cases the stopcock goes off first, then the phone. Everything milder than that is still worth a prompt visit — a leak never gets cheaper by waiting — but it can be booked at civilised rates rather than emergency ones.
Condensation tends to show on cold surfaces — window reveals, outside walls, behind furniture — and comes and goes with the weather and the washing. A leak stays put, follows pipework or sits below a bathroom, and keeps growing whatever the season. The stopcock test settles it: with everything off and the stopcock closed, a condensation patch behaves no differently, but a leak-fed patch stops getting worse.
Very often, yes. A sealed heating system that needs topping up week after week is losing water somewhere — a weeping radiator valve, a joint under the floor, or occasionally a fault inside the boiler itself. Keep a note of how often you top up and mention it when you call. Endless top-ups aren't a fix; they're a symptom being fed.
Only if your home has a water meter, and most homes in Northern Ireland don't — household water isn't billed by meter here the way it is in much of England. If you do have one, the test is simple: read the meter, use no water for 30 to 60 minutes, and read it again. Movement with everything off means water is escaping somewhere. For everyone else, the signs are physical: damp, stains, smells and the pressure gauge.
Three situations move it from 'book a visit' to 'ring now': water anywhere near sockets, light fittings or the consumer unit; a ceiling that's sagging or bulging; and a patch that's visibly spreading while you watch. In those cases shut the stopcock, keep clear of anything electrical that's wet, stay out from under a bulging ceiling, and make the call.
Usually, yes — narrowing down by which pipes run where, isolating sections, and checking the obvious suspects first: bathroom seals, radiator valves, washing machine connections, joints under sinks. Some leaks do end up needing a floorboard up or a bit of ceiling opened, but that's the end of the trail, not the starting point. Describe what you've seen and when it started, and you shorten the hunt.
The main page — how the line works and who it covers.
Go to home →Stopcock off first — the right order for the first five minutes.
Read the guide →Pressure, error codes, frozen condensate — and the gas rule.
Read the guide →Pressure, timers, tripped switches and the immersion backup.
Read the guide →Gentle heat from the tap end back — and never a flame.
Read the guide →What to try, what to never pour, when it's NI Water's job.
Read the guide →How the bill is built and what to pin down first.
Read the guide →Any hour, any day — you'll be put through to a local plumber covering Dungannon and the surrounding towns and villages.
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