Frozen or Burst Pipes in London: What to Do and How to Prevent Them (2026)

Last updated: September 2026

A burst pipe is one of the most stressful things that can happen in a home, and in London, where so much of the housing stock is older terraces and converted flats, a single cold snap can turn a hairline weakness into a flood. This guide walks you through exactly what to do in the first few minutes, how to thaw a frozen pipe safely, how to stop it happening in the first place, and who is responsible when the water starts coming through the ceiling.

TL;DR

If a pipe bursts, turn off the water at your stop tap straight away, switch off the boiler, open the taps to drain the system, and soak up the water. Keep away from any electrics the water has reached. Then call a WaterSafe-registered plumber. Prevention is mostly lagging, low heating, and draining down if you go away.

What to do if a pipe bursts right now

Speed matters more than anything else here. Every minute the water keeps flowing is more damage to floors, ceilings, and anything below. Follow these steps in order [1].

1. Turn off the water at the stop tap. This is the single most important action. Turn the valve clockwise, slowly, until the flow stops. It can take a minute or two for the water to drain away fully.
2. Switch off the boiler and any water heating. This protects the system once the cold supply is cut off.
3. Open all the cold taps to drain the pipes. This empties the remaining water in the system so less of it ends up on your floor. Keep a bucket of water back for flushing the toilet and washing your hands.
4. Soak up the escaping water with towels to limit the damage while you wait for help [1].
5. Stay away from electrics. If water has leaked near sockets, light fittings, or the consumer unit, do not touch them. Switch the power off at the fuse box if you can reach it safely, and leave it off until an electrician has checked it [1].
6. Call a qualified plumber. Use the WaterSafe register to find someone accredited to work on your water system, or find a local plumber through Loacally.
7. Take photos before you clear up. Insurers generally want to see the damage as it happened, so photograph the affected areas and keep any receipts for emergency work.

Turn off the water supply coming into your property at the stop tap and switch off your boiler. Soak up escaping water with towels to limit the damage.

-- Met Office, frozen or burst pipe advice [1]

Do not try to repair a burst section yourself with tape or a makeshift clamp and then turn the water back on. A rushed patch under mains pressure often fails, and a second burst while you are mopping up the first one is a genuinely bad day. Wait for the plumber.

What to do if a pipe has frozen but not burst

A frozen pipe is a warning, not yet a disaster. The ice expands and puts the pipe wall under pressure, so the goal is to thaw it gently before it splits [1].

• Turn off the inside stop tap as a precaution.
• Open the nearest cold tap while the stop tap stays off. This relieves the pressure building behind the ice.
• Thaw the pipe slowly with hot water bottles or towels soaked in hot water, working from the end nearest the tap back towards the blockage.

Never use a naked flame or a blowtorch to thaw a pipe. The Met Office is explicit that direct heat "may cause permanent damage to the pipes and could also lead to a fire in the home" [1]. A hairdryer on a low setting, held well back, is the most heat you should ever apply.

If the pipe that has frozen is your boiler condensate pipe (a plastic pipe running outside to a drain), the boiler will often cut out in cold weather. You can safely warm the exposed outside section with a warm, not boiling, cloth or a hot water bottle. What you must not do is cut, dismantle, or alter any part of the boiler or its pipework yourself. Work on gas appliances must be carried out by a Gas Safe registered engineer, by law [5]. If warming the visible pipe does not restart the boiler, book a registered engineer.

How to find your stop tap before you need it

The worst time to go looking for your stop tap is while water is pouring through a light fitting. Find it today. In most homes the internal stop tap is under the kitchen sink, but it can also be in a downstairs bathroom, a kitchen cupboard, a garage, a cellar, or under the stairs [1][2]. It looks like a tap without a spout, or a lever, sitting between two lengths of pipe [2].

If you live in a flat, you may not have an individual stop tap inside your own home at all. The supply is sometimes controlled in a communal riser or centrally for the whole building. If you cannot find one inside your flat, ask your freeholder or managing agent where yours is and label it. In older Victorian terraces, the internal tap is commonly under the kitchen sink, with an external stop tap near the boundary under a small cover by the pavement as a backup. Turn the valve slowly and never force it, because an over-tightened stop tap can be damaged [2].

How to prevent frozen pipes in the first place

Prevention is cheaper and far less stressful than a repair. The risk builds whenever temperatures drop to freezing and below, and it rises sharply during sustained cold snaps of several days, which is why December to February is the core risk period in London. None of these steps is expensive.

• Lag your pipes. Foam pipe insulation keeps the warmth in and the frost out, especially in the coldest spots: lofts, garages, basements, and anywhere pipes run through an unheated space [3]. Fit insulated covers on outside taps.
• Keep the heating ticking over in cold weather. WaterSafe recommends setting your thermostat to at least 14C during a cold snap to keep pipes above freezing [3]. That is lower than a comfortable living temperature but enough to protect the plumbing.
• Fix dripping taps before winter. Even a slow drip can freeze and cause a blockage [3].
• Drain down if you go away. If you are leaving the property empty for an extended period, turn off the water supply and open the taps until the flow stops [3]. This is not just good advice; protecting pipes against freezing is a requirement under the Water Regulations, through insulation, trace heating for shallow-laid pipes, or draining unoccupied premises [4].

Be realistic about what insulation can do. WaterRegsUK is candid that insulation "may delay but not prevent freezing" in a severe or prolonged freeze [4]. Lagging buys you time and protects against ordinary cold; in an exceptional freeze, keeping some heat on and knowing where your stop tap is still matter.

Who is responsible for a burst pipe?

This depends on whether you rent, own a leasehold flat, or own the freehold, and it is worth knowing before anything goes wrong.

If you rent

Your landlord is responsible for most major repairs, including the pipes, the water supply installations, and the heating and hot water system [6]. Importantly, these duties "cannot be removed by anything your tenancy agreement says" [6], and they are echoed in the Government's own guidance for renters, which puts the water supply and heating installations squarely with the landlord [7].

There is one catch that causes a lot of disputes: your landlord only has to act once they know there is a problem [6]. Report a leak, a frozen pipe, or a failed boiler in writing as soon as you spot it, and keep a copy. That written notice is what starts the landlord's responsibility running.

If you own a leasehold flat

As a general rule, the leaseholder is responsible for repairs inside their own flat, including the internal plumbing, while the freeholder looks after the building's structure and the shared parts [8]. Shared or communal pipework that serves several flats is usually the freeholder's or management company's responsibility, funded through the service charge, but this is a convention rather than a universal rule. Your actual answer is in your lease, so check it, and if it is unclear, the Leasehold Advisory Service (LEASE) offers free guidance.

Will insurance cover it?

Escape of water, the insurer's term for a burst or leaking pipe, is one of the most common and costly categories of home insurance claim, which is exactly why policies pay close attention to prevention. Two things commonly catch people out. First, leaving your home unoccupied for a long stretch, often more than 30 days, can mean your insurer will not cover damage that happens while you are away [9]. Second, some policies are stricter in winter precisely because unheated homes are more likely to suffer burst pipes [9]. If you plan to leave a property empty over the colder months, look into unoccupied-property cover and follow the drain-down steps above.

This is general information, and the detail that matters is in your own policy: check the excess, the unoccupancy clause, and any maintenance conditions before you need to claim.

When to call a professional, and what it costs

A burst or frozen pipe is rarely a job to take on yourself. For the repair itself, use a WaterSafe-registered plumber. WaterSafe is the national register of plumbers competent to work under the Water Regulations, and accredited businesses carry minimum levels of public liability insurance [10]. For anything involving the boiler or gas appliances, the engineer must be Gas Safe registered, without exception [5].

Emergency call-outs to attend a burst pipe in London, especially out of hours, typically cost more than a routine booking. We keep a dated breakdown in our guide to emergency plumber costs in London, and if you would rather compare hourly rates first, see how much a plumber costs per hour in London. When you are hiring in a hurry, it is still worth a two-minute check on who you are letting in; our guide to finding a trusted tradesperson in London covers the checks that matter. If the cause turns out to be an ageing boiler, our new boiler cost guide explains the options.

Frequently asked questions

What is the first thing to do if a pipe bursts?

Turn off the water at your stop tap immediately by turning the valve clockwise until the flow stops. Then switch off the boiler, open the cold taps to drain the system, and soak up the water. Keep away from any electrics the water has reached, and call a WaterSafe-registered plumber.

At what temperature do pipes freeze?

Pipes are at risk once temperatures fall to freezing point, around 0C, and the danger rises sharply during sustained cold snaps of several sub-zero days and nights. In London the core risk period runs from December to February. Pipes in unheated lofts, garages, and outside runs freeze first, so insulate those.

Can I thaw a frozen pipe with a hairdryer?

You can use gentle heat such as a hairdryer on a low setting, hot water bottles, or towels soaked in hot water, working from the tap end towards the blockage. Never use a naked flame or a blowtorch. The Met Office warns that direct heat can permanently damage the pipe and cause a fire.

Who is responsible for a burst pipe in a rented flat?

Your landlord is responsible for repairing pipes, water supply, and heating, and this cannot be overridden by your tenancy agreement. However, the landlord only has to act once they know about the problem, so report any leak or frozen pipe in writing straight away and keep a copy of the notice.

Where is my stop tap if I live in a flat?

In a flat your stop tap may be inside a kitchen cupboard, but it is often in a communal riser or controlled centrally for the whole building, so you may not have one in your own home. If you cannot find it, ask your freeholder or managing agent, then label it so you can reach it fast in an emergency.

Find a trusted local plumber

Whether you need an emergency repair now or want a plumber to lag your pipes before winter, Loacally connects you with local tradespeople across London, each reviewed by hand before their profile goes live. Find a trusted local plumber near you and get the job sorted properly.

Sources

1. Met Office. "What to do if you have a frozen or burst pipe." https://weather.metoffice.gov.uk/warnings-and-advice/seasonal-advice/your-home/frozen-or-burst-pipes (accessed September 2026)
2. WaterSafe. "How can I locate my internal stop tap to turn off my water?" https://www.watersafe.org.uk/advice/general_plumbing_advice/winter_advice/locate-internal-stop-tap/ (accessed September 2026)
3. WaterSafe. "Plumbers' winter warning to avoid burst water pipes and flooding." https://www.watersafe.org.uk/news/latest_news/plumbers_winter_warning_burst_pipes/ (accessed September 2026)
4. WaterRegsUK. "What protection against freezing is required?" https://www.waterregsuk.co.uk/topics/all-faqs/what-protection-against-freezing-is-required/ (accessed September 2026)
5. Gas Safe Register. Official guidance on gas appliance work and boiler condensate pipes. https://www.gassaferegister.co.uk/ (accessed September 2026)
6. Citizens Advice. "Check if your landlord has to do repairs." https://www.citizensadvice.org.uk/housing/repairs-and-housing/repairs-and-housing-conditions/whos-responsible-for-repairs/check-if-your-landlord-has-to-do-repairs/ (accessed September 2026)
7. Gov.uk. "How to rent: a safe home." https://www.gov.uk/government/publications/how-to-rent-a-safe-home/how-to-rent-a-safe-home (accessed September 2026)
8. Shelter England. "Leasehold flats and houses: responsibilities for repairs." Updated 11 January 2024. https://england.shelter.org.uk/housing_advice/repairs/leasehold_flats_and_houses_responsibilities_for_repairs (accessed September 2026)
9. Confused.com. "What can invalidate your house insurance?" Updated 17 October 2025. https://www.confused.com/home-insurance/guides/what-can-invalidate-house-insurance (accessed September 2026)
10. WaterSafe. "Finding a plumber." https://www.watersafe.org.uk/advice/hiring_a_plumber/finding_a_plumber/ (accessed September 2026)