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Some blockages give way to ten minutes and a plunger. Others are telling you something bigger. Here's how to tell which one you've got.
What do we do about a blocked drain right now? Stop running water into it, try a plunger with the overflow blocked off, and check your outside gully for anything obvious. If the water won't shift, or more than one fixture is backing up together, ring 020 4577 2888 to be put through to a local plumber — pushing on with chemicals rarely ends well.
Count what's misbehaving. One slow sink is likely a local clog you can clear yourself; several fixtures backing up or gurgling together means the blockage is further down the line.
This one question decides your whole evening, so answer it before touching a plunger. Walk the house: is it just the kitchen sink, or is the bath slow too? Does the toilet gurgle when the basin empties? Is water standing in the outside gully?
A single misbehaving fixture usually means hair, grease or food waste sitting in the trap or the first stretch of waste pipe — annoying, local, and often fixable by hand. But when fixtures start talking to each other — a gurgle here when water drains there, or the lowest drain in the house backing up first — the blockage sits in a shared pipe below all of them, and plunging one plughole won't reach it. That's the point to think about the drain run as a whole, and usually the point to bring in someone with rods or a jetter.
Trap, plunger, gully — in that order, with a bit of patience. These three clear the honest majority of single-fixture blockages.
What to skip: kettle after kettle of boiling water into plastic pipework, mixing chemical uncloggers, and poking improvised wire down the WC — a bent coat hanger scratches pans and pushes blockages tighter more often than it retrieves anything. If your three honest attempts haven't shifted it, the blockage has won round one; give a plumber round two.
Fat, wipes, and anything that isn't the three Ps — pee, poo, paper. Nearly every kitchen blockage and most bathroom ones start with these.
Cooking fat is the great deceiver: it pours away as an innocent liquid and sets in the pipe as something close to candle wax, catching every crumb that follows it. Let it cool, jar it, bin it. "Flushable" wipes are the other repeat offender — flushable in the sense that they vanish from the bowl, not in the sense that they break down. They don't, and they knit together with fat into the exact lumps that drainage engineers pull out of pipes every week.
Add to the never list: coffee grounds, rice and pasta (both swell), plaster and grout from DIY jobs, cotton pads and cat litter. One habit protects a house more than any gadget: a sink strainer in the kitchen, and a bin beside the toilet for everything that isn't paper. If your home runs on a septic tank rather than mains drainage — as plenty do out toward Feeny, Drumsurn and the townlands beyond Dungiven — all of this counts double, because a tank forgives even less than a sewer does.
Rough rule: your pipes, your problem — the shared and public bits are generally NI Water's. If the neighbours are backing up too, it's probably not your blockage.
The boundary works broadly like this in Northern Ireland: drains inside your property boundary that serve only your home are the owner's responsibility, while public sewers — and shared sewers beyond the boundary — generally fall to NI Water. So a blocked kitchen waste or a single overflowing gully is your side of the line; a manhole lifting in the street, sewage surfacing on the road, or several houses along a terrace backing up at once points to the public network, and that's the sort of thing to report to NI Water rather than pay a plumber to chase.
The older streets off Main Street, where houses share drainage runs laid down generations ago, are exactly where the "is it ours or theirs?" question comes up most. A quick word with the neighbours before you book anyone can save you a call-out fee — and a plumber worth their salt will tell you plainly when a blockage genuinely isn't yours to fix.
Use them sparingly, if at all. They can shift light grease near the plughole, but against a solid blockage the caustic liquid just sits in the pipe — and the next person to plunge or rod that drain gets a splash of it. If one dose hasn't worked, stop pouring and switch to mechanical methods or a professional instead.
Gurgling is air being dragged through water where it shouldn't be, and when one fixture talks while another drains, they're arguing over a partly blocked shared pipe. It's an early warning worth heeding — drains rarely clear themselves, and the gurgle usually arrives well before the overflow does.
Broadly: drains inside your boundary that serve only your property are yours; public sewers, and shared sewers beyond your boundary, are generally NI Water's territory. If several houses back up at once, or a manhole in the street is overflowing, that's one to report to NI Water. If it's just your own gully or WC, it's your side, and a plumber is the right call.
It's the drain telling you the blockage sits beyond that point, not in whatever sink you've been plunging. Lift the gully grid if you can and clear out any leaves or silt — that alone fixes a surprising number. If the gully itself stays full or wastewater keeps rising, the run below ground needs rodding or jetting, and that's professional work.
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