Burst pipe or leak? What to do before the plumber arrives

A burst pipe or a sudden leak is one of those problems where the first five minutes matter more than almost anything a plumber does afterwards. You do not need plumbing skills to limit the damage — you need to know where a couple of key things are, and to work through a short, calm sequence rather than a panicked one.

The single most useful thing you can do, and the first thing worth doing right now, before you ever have a leak, is find your internal stopcock. This is the valve that shuts off the mains water supply to your home, and in most UK houses it is found under the kitchen sink, in a downstairs cupboard, under the stairs, or in a utility room — commonly a small tap-like valve or a lever on the incoming pipe. Turn it clockwise to close it. Many homes also have a second, external stopcock, usually in a small covered box near the boundary of the property or under the pavement, which the water company can use, but this often needs a special key and is not always something homeowners can access quickly — the internal one is the one to know.

If you discover a leak or a burst, go straight to the stopcock and turn off the water before doing anything else. Then open the cold taps in the house, starting with the one nearest the leak, to drain the remaining water sitting in the pipes and relieve pressure — this will not stop water that has already escaped, but it reduces how much is left to come out. If the leak involves a hot water cylinder or tank rather than the mains, you may also need to turn off the boiler or immersion heater, since heating an empty or partially empty system can cause further damage.

Water and electrics are a genuinely dangerous combination, so treat this step seriously. If water is anywhere near sockets, switches, ceiling light fittings, or is dripping onto — or worse, pooling near — the consumer unit (fuse box), turn off the relevant circuit at the consumer unit if you can reach it safely and it is not wet. Never touch a switch, socket or the consumer unit itself with wet hands, and if water is actively running near electrics, is coming through a light fitting, or you are at all unsure, the safest move is to leave that room, switch off the mains electricity supply only if it can be done without touching anything wet, and call an electrician or, in a serious situation, the emergency services rather than take a risk.

With the water and any relevant electrics dealt with, focus on containing the damage. Buckets and towels under an active drip, moving furniture, rugs and electronics out of the way, and lifting carpets where you can will all reduce how much soaks in before help arrives. If an appliance like a washing machine or dishwasher is near the leak, turning it off at the isolation valve, if it has one, is a sensible extra precaution even if it is not the source.

Once the immediate danger is dealt with, it is worth thinking about any insurance claim before you start cleaning up. Most UK home insurance policies cover escape of water as standard, though the exact terms, excess and any exclusions vary by policy, so this is general information rather than advice on your specific cover. Photograph and, if you can, video the damage — the source of the leak, the affected rooms, and anything damaged — before you move or dispose of anything. Keep any receipts for emergency work, such as a plumber's call-out, and for temporary repairs like a professional drying service, since insurers often ask for these. Contact your insurer promptly to find out whether you need their approval before arranging repairs, and check whether you have home emergency cover, separate from the main buildings policy, that might cover the plumber's call-out itself.

If the cause is a frozen pipe that has not yet burst, resist the temptation to thaw it quickly with an open flame or a very high heat source, which can damage the pipe or, near a wall cavity, create a genuine fire risk. Gently warming the area with a hairdryer on a low setting, or simply raising the room temperature, is a safer approach while you wait for a plumber.

Once the water is off, the immediate risk to people and electrics is dealt with, and you have taken a few photos, call a plumber and explain clearly what has happened — whether the stopcock is off, roughly where the leak is, and whether it is still active. If you have home emergency cover, check whether you are expected to use a nominated contractor before booking someone yourself, since some policies only pay out if you do.

A burst pipe is rarely a single afternoon's problem to sort out fully — drying out, repairs and sometimes redecoration can take longer than the plumbing fix itself — but acting fast in the first few minutes makes a real difference to how much of that follow-on work you end up needing. Our directory lists plumbers covering towns and cities across the UK, so it is worth finding one local to you before you need one in a hurry.

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