It’s 11pm on a Tuesday and there’s water coming out from under your kitchen cabinet. Or maybe you’ve just walked into the bathroom and the ceiling below is already starting to sag. If you’re reading this right now with a towel in one hand and your phone in the other, skip ahead to the next section — we’ll get you sorted first, then explain the rest once the water’s off.
A burst pipe is one of those things nobody thinks about until it’s happening to them. And when it does happen, the first ten minutes matter more than almost anything else — how much damage you end up with often comes down to how fast you can stop the water and how calm you can stay while you do it.
We’re KOZ Plumbing & Heating, and we deal with burst pipe callouts across London every single week — more of them than you’d think, especially once the cold weather sets in. This guide walks you through exactly what to do in the moment, why pipes burst in the first place, and how to make sure the next available plumber isn’t someone who’s going to make things worse.
Step 1: Turn Off Your Water Supply — Do This First
Before you do anything else, before you even reach for a towel, find your stopcock and turn it off.
In most London homes, the stopcock is located:
- Under the kitchen sink
- In a cupboard near the front door
- In the utility room or under the stairs
- In older Victorian and Edwardian terraces (common across areas like Islington, Clapham, and Hackney), it’s sometimes tucked away in a hallway floor box or a cupboard that hasn’t been opened in years
Turn it clockwise to shut it off. If it’s stiff — which happens a lot with stopcocks that haven’t been touched in a decade — don’t force it hard enough to snap the handle. A firm, steady turn is usually enough. If you genuinely can’t get it to move, that’s exactly the kind of thing to mention when you call us, because it changes how urgently we need to get to you.
If you can’t find your internal stopcock at all, there should be an external stop valve near your property boundary, usually under a small metal cover in the pavement or front garden. These are trickier to access and often need a special key, so don’t waste precious minutes searching for it if the internal one is findable.
Can’t find either one? Don’t panic. Call us and keep working through the next steps — every minute you spend limiting the damage is worth it even before the water’s fully off.
Step 2: Turn Off Your Electrics Near the Leak
Water and electricity are a genuinely dangerous combination, and it’s the part people forget in the panic of the moment.
If water is anywhere near sockets, light fittings, or your consumer unit (fuse box), switch off the electricity supply to that area at the fuse box — or the whole house if you’re not sure which circuit covers the affected room. Never touch a switch or socket with wet hands, and don’t step into standing water near an active circuit.
If the leak is close to your consumer unit itself, don’t touch it. Leave the property if needed and call us immediately — this is one of the few plumbing situations where we’d also tell you to consider calling an electrician or the fire brigade if there’s any visible sparking or burning smell.
Step 3: Drain the System and Contain the Water
Once the water’s off at the stopcock, open your cold taps (starting with the one closest to the burst, then others around the house) to drain the remaining water sitting in the pipes. This relieves pressure and reduces how much water continues to leak out even after the supply is shut off.
While that’s draining:
- Move anything valuable away from the water — furniture, electronics, rugs, boxes stored on the floor
- Use towels, buckets, and any spare containers to catch and contain water
- If water is coming through a ceiling light fitting or bulging patch of ceiling, get well clear of that spot — a waterlogged ceiling can come down without warning
- Take a few photos on your phone of the damage as it’s happening. If you end up making an insurance claim, this documentation is genuinely useful and easy to forget once the crisis is over
Step 4: Call an Emergency Plumber
This is the point where you call someone who does this for a living. A burst pipe isn’t usually a DIY fix — even if you’ve stopped the immediate flooding, the underlying pipe still needs proper repair, and depending on where the burst happened, there may be damage behind walls or under floors that isn’t obvious yet.
When you call, it helps to have ready:
- Roughly where the leak is (kitchen, bathroom, under a specific floorboard, near the boiler, etc.)
- Whether you’ve managed to shut the water off completely
- Whether the leak is from a visible pipe or coming through a wall/ceiling from somewhere you can’t see
- Your postcode and access details, especially if you’re not going to be the one answering the door
We cover emergency plumbing across London and the surrounding towns, and we aim to have someone with you as quickly as possible — a burst pipe is exactly the kind of job that doesn’t wait until morning.
Why Do Pipes Burst? The Real Causes (Not Just “Old Pipes”)
Homeowners often assume a burst pipe means their whole plumbing system is falling apart. Usually, it’s more specific than that. Here’s what we actually see on callouts:
1. Frozen Pipes (Most Common in Winter)
When water freezes inside a pipe, it expands — and pipes, especially older metal ones, don’t expand with it. The pressure builds until something gives, usually at a joint or a weak point in the pipe. This is why burst pipe callouts spike sharply during cold snaps, particularly for pipework in unheated spaces like lofts, garages, and exterior walls.
If you know a cold snap is coming, keeping your heating on low overnight (rather than off) and leaving loft hatches slightly open to let warm air circulate can genuinely prevent this.
2. Ageing or Corroded Pipework
A huge amount of London’s housing stock is Victorian, Edwardian, or otherwise older than 60-70 years. Original pipework — particularly older copper or, in some cases, remaining sections of lead or galvanised steel — corrodes and weakens over decades. A pipe that’s been slowly thinning from the inside can eventually just give way, often with no obvious warning sign beforehand.
3. High Water Pressure
If your water pressure is set too high for your system, it puts constant extra stress on every joint and seal in your pipework. Over time, this can cause a rupture at the weakest point — often not where you’d expect.
4. Poor Original Installation or Botched DIY Work
We see this more than people expect: a pipe run that was never properly supported, an amateur joint that was soldered incorrectly, or pipework that was damaged during a previous renovation (someone drilling a shelf bracket straight through a pipe hidden in a wall is a classic one).
5. Ground Movement and Building Settlement
Particularly relevant in London due to clay-heavy soil, which expands and contracts with moisture levels. This movement can shift pipework enough over time to cause stress fractures, especially in older or rigid pipe materials.
6. Blocked or Restricted Pipes
A blockage further down the line — whether from limescale buildup, grease, or debris — forces water to back up and put pressure on pipework it was never designed to handle. Over time, a chronic partial blockage can be the hidden reason a seemingly random pipe eventually splits. This is one of the reasons we always recommend getting recurring slow drainage looked at rather than just living with it.
7. Poor Water Quality and Hard Water Buildup
London sits in a hard water area, and over years that mineral buildup narrows pipework from the inside and puts extra strain on joints, valves, and fittings. It’s a slow process, which is exactly why it tends to go unnoticed until something finally gives.
Is This a True Emergency, or Can It Wait Until Morning?
Not every plumbing problem needs a 2am callout, and knowing the difference can save you money and stress. Here’s a rough way to think about it:
Call immediately, any time of day or night, if:
- Water is actively flowing and you can’t stop it at the stopcock
- Water is coming through a ceiling, light fitting, or near your consumer unit
- You have no heating or hot water and there are young children, elderly residents, or anyone medically vulnerable in the home during cold weather
- A burst has happened near your boiler or gas supply
Can usually wait until regular hours if:
- You’ve successfully stopped the leak at the stopcock and it’s fully contained
- It’s a slow drip rather than an active flow
- Your heating has gone off but the weather is mild and no one in the home is vulnerable to the cold
- A tap is dripping or a toilet is running but nothing is actively flooding
If you’re ever unsure which category you’re in, call anyway and describe what’s happening. A good emergency plumber will tell you honestly whether it needs someone out immediately or whether it’s safe to book in for the next available slot — we’d always rather talk you through it on the phone than have you sit up all night worrying unnecessarily, or worse, wait on something that actually needed immediate attention.
What Affects the Cost of a Burst Pipe Repair
People searching for help with a burst pipe are usually also trying to work out roughly what it’s going to cost them, so it’s worth breaking down honestly what actually drives the price:
Time of call. Most plumbers, us included, have a standard rate for regular working hours and a higher rate for out-of-hours emergency callouts (evenings, weekends, and bank holidays). This isn’t padding the bill — it reflects that we’re keeping a team available around the clock specifically for situations like yours.
Access to the pipe. A burst pipe that’s fully exposed under a sink is a very different job from one that’s buried behind a tiled wall, under floorboards, or embedded in a concrete floor. Repairs that require cutting into a wall or lifting flooring naturally take longer and cost more, partly because of the plumbing work itself and partly because of the making-good afterwards.
Extent of secondary damage. The pipe repair itself is often the smaller part of the job. Water that’s travelled into a ceiling void, soaked into flooring, or run down into a room below can mean drying out, replastering, or even structural drying equipment — none of which is part of the plumbing bill itself, but which is worth knowing about upfront so you’re not caught off guard.
Parts required. A straightforward push-fit repair on an accessible copper pipe is inexpensive. A full section replacement, especially on older pipework where matching materials or fittings isn’t straightforward, costs more.
Whether it’s a temporary or permanent fix. Sometimes the priority in the moment is simply getting your water safely back on, with a permanent repair scheduled as a proper follow-up job. We’ll always be upfront with you about which one we’re doing and why.
The honest answer is that no reputable plumber can give you an exact figure without seeing the problem — but a reputable one will always give you a clear estimate before starting, and will explain what’s driving the cost if it’s more complex than expected.
What Happens When We Arrive
Understanding what a proper emergency callout actually involves can help you know what to expect (and what to be wary of, since burst pipe emergencies are unfortunately a favourite target for callout scams).
- Locate the source. Even if you’ve found the general area, we trace the exact point of failure — sometimes the visible leak isn’t where the pipe actually burst.
- Assess the damage. We check for secondary damage — water that’s travelled along joists, behind plasterboard, or under flooring isn’t always visible immediately.
- Temporary or permanent fix. Depending on the pipe, access, and time of day, we’ll either carry out a permanent repair on the spot or a safe temporary fix to get your water back on, with a full repair scheduled straight after.
- Clear pricing before we start. You should always be told the cost before work begins — not after. If a “24/7 emergency plumber” won’t give you a price upfront, that’s a warning sign.
How to Avoid Getting Overcharged in an Emergency
Emergency situations are exactly when people are most vulnerable to being overcharged, and it’s worth knowing what to look out for:
- Get the callout fee and hourly rate confirmed before booking, not after the plumber is already at your door
- Be cautious of anyone who won’t give a rough estimate over the phone based on what you describe
- Check for proper licensing and insurance — a legitimate plumber should be able to confirm this without hesitation
- Ask if VAT is included in any quote you’re given
- Avoid anyone pressuring you into unnecessary extra work while they’re already on site fixing the original issue
Preventing Future Burst Pipes: A Quick Seasonal Checklist
Before winter:
- Insulate exposed pipework in lofts, garages, and under-sink cupboards
- Know where your stopcock is (and check it turns freely) before you need it in an emergency
- Keep heating on a low, consistent setting during very cold spells rather than switching it off completely when you’re out
Year-round:
- Get your water pressure checked if you’ve never had it assessed
- Address small leaks or damp patches early — they’re often an early warning sign of a weakening pipe, not just a nuisance
- If you’re renovating or having shelving/cabinetry installed, make sure whoever’s doing the work checks for pipework behind walls first
Frequently Asked Questions
How do I know if I have a burst pipe versus a small leak?
A burst pipe usually means a sudden, significant flow of water rather than a slow drip or damp patch. If water is actively pooling, spraying, or coming through a ceiling or wall rapidly, treat it as a burst pipe emergency and follow the steps above.
Will my home insurance cover a burst pipe?
Most UK home insurance policies cover burst pipe damage, but it’s always worth checking your specific policy, especially around excess costs and what counts as “escape of water” cover. Photos taken during the emergency (as mentioned above) help significantly with any claim.
How much does an emergency plumber cost in London?
Costs vary depending on the time of day, the complexity of the job, and access to the affected pipe. A reputable plumber should always confirm pricing with you before starting work — we’re always upfront about costs on the phone before we arrive.
Can I fix a burst pipe myself temporarily?
Once the water is off, a pipe repair clamp or rubber and hose clip can sometimes offer a very temporary containment for a small crack — but this is not a fix, and it’s not appropriate for anything beyond a tiny pinhole leak. For anything more significant, wait for a professional rather than risk making the damage worse.
What areas do you cover for emergency callouts?
We respond to emergency plumbing and heating callouts across London and the surrounding areas. If you’re not sure whether you’re in our coverage area, just give us a call and we’ll let you know straight away.
Why did my pipe burst even though it’s not that cold outside?
Freezing is the best-known cause, but it’s far from the only one. Ageing pipework, high water pressure, hidden corrosion, or a small amount of accidental damage from previous building work can all cause a pipe to fail at any time of year. If a pipe bursts in mild weather, it’s often a sign that the pipe was already weakened and something — a pressure spike, vibration, or ground movement — was simply the final trigger.
Should I try to repair the pipe myself before calling a plumber?
Focus your energy on stopping the water and containing the damage, not on repairing the pipe. Even a well-intentioned temporary fix, like wrapping tape around a split pipe, can mask the extent of the damage or fail suddenly once pressure is reintroduced. It’s far safer, and usually faster overall, to get a professional to assess and repair it properly the first time.
A Quick Word on Peace of Mind
If you’ve just been through a burst pipe, it’s worth taking five minutes once things have calmed down to note down where your stopcock is, so it’s not something you’re searching for under pressure next time. It’s a small thing, but it’s genuinely one of the most useful pieces of household knowledge you can have — right up there with knowing where your fuse box and gas shutoff are.
If this has happened once, it’s also worth having your pipework generally assessed rather than just waiting to see if it happens again. A short inspection can often catch a second weak point before it turns into another late-night emergency.
If You’re Dealing With This Right Now
If you’ve got water coming through your home right now, don’t keep reading — call us. We handle burst pipe emergencies across London every day, and getting the right help quickly is what actually limits the damage, not researching the perfect fix.
Call KOZ Plumbing & Heating now →
For everything else — routine plumbing, heating servicing, drain issues, or bathroom work — you can browse our full range of services or get in touch for a free quote.
KOZ Plumbing & Heating Ltd provides 24/7 emergency plumbing and heating services across London and the surrounding areas, including Peterborough, Cambridge, Oxford, Watford, Northampton, Swindon, Colchester, Essex, Reading, Guildford, Uxbridge, Bedford, Luton, and Milton Keynes.