FAQs for Tackling Frozen and Burst Pipes

The winter months often pose significant threat to heating and water systems, as extreme cold can lead to plumbing disasters. As temperatures across the UK plummet, it’s important to know: When do pipes freeze, how can you keep it from happening, and who do you call when you have a burst pipe?

Here, we answer some of the most commonly asked questions about frozen and burst pipes.

Why do pipes freeze?

Your pipes are likely to have some water in them, even if your taps aren’t turned on. When temperatures drop, the water within exposed or uninsulated pipework is susceptible to freezing. This could leave you without running water.

Why is it bad for pipes to freeze?

If pipes freeze, water supplies to taps, showers and toilet cisterns, or your boiler could be limited. Frozen water in the pipes may also lead to boiler damage, cracked or burst pipes, and substantial leaks. Damage caused by these can be incredible costly to put right. In fact, the average cost of remedying the impact of burst pipes in domestic properties was £9,300, according to 2021 statistics from the Association of British Insurers.

When should I be worried about pipes freezing?

Pipes are at risk of freezing when temperatures drop below 0°C.

How do you know if pipes are frozen?

Here are some of the warning signs that your pipework is frozen or burst:

• Lack of water coming out of your taps
• Central heating making a gurgling sound or in lockout
• Your boiler won’t switch on
• The toilet will not flush

Can pipes freeze in one night?

Yes, pipes can freeze in as little as six hours.

How do you keep your pipes from freezing?

To help avoid problems with freezing pipes, you should identify where your internal stopcock/stop-valve is and ensure it’s in working order – try to check it still functions every six months. Also, be sure to have regular boiler services. If you’ve not done so already, it’s a good idea to insulate all pipes in locations vulnerable to the cold, too.

If you have plans to leave your home unoccupied for a prolonged period, you may wish to turn off the water supply via your stop-valve as this will significantly reduce the risk of any pipes freezing. Open the taps and run off any remaining water. If you are able, try draining the pipes out to make sure they are completely empty. It is also recommended that repairs on dripping taps are prioritised because doing so will prevent ice forming.

Advice for those with a smart thermostat in their home is to use the anti-frost setting to prevent pipes from freezing. While we appreciate rising energy bills may deter you from putting your heating on, the cost of frozen pipes is significantly higher. Therefore, heating your home is a recommended investment for reducing the disruption, distress and expense that could be caused by freezing pipework this winter. In addition, if your radiator valve has a snowflake symbol, this allows you to control the water temperature and flow. To prevent freezing, set it to a minimal flow between pipes and radiators.

How do I know if my boiler condensate pipe is frozen?

If you hear gurgling noises coming from your heating system and the boiler shuts down during freezing temperatures, it is possible that your condensate pipe has frozen. This is part of a failsafe mechanism to protect the boiler from water going back up the pipe and inside the boiler, causing damage to the electrics etc.

Look for a plastic pipe connected to your boiler that runs outside. If safe to do so, pour warm (not boiling) water along the pipe to gently thaw it. Reset your boiler and, if the pipe has been successfully defrosted, the boiler should start normally again. If you are unable to do any of this yourself, call a professional for advice and assistance

What should I do if my pipes freeze?

In the first instance, turn off your water mains using your stop-valve. The stop-valve regulates and controls the flow of mains water, allowing you to shut off the water for repairs or to avoid disasters. Then, locate the frozen pipe and thaw out pipes slowly. Only ever attempt to thaw pipes that are easily accessible and/or at ground level, and always start thawing at the end nearest the tap. Recommended methods include hot water bottles or towels soaked in hot water. You could also try wrapping heated cloths around the pipework. Be careful because even if water is flowing from taps, other parts of the system may still be frozen.

Avoid using boiling water for thawing as this can be problematic if there are splits in the pipe that you haven’t spotted – since they’re not always noticeable. Avoid using a naked flame as this could damage your pipes or start a fire from flammable material.

What should I do if my pipes burst? / What to do if you have a burst pipe?

In the instance of a burst pipe, once you have turned off the water supply, you should seek the assistance of a plumbing professional. Do not touch electrics if these have been affected by water and turn them off via the fuse box /consumer unit box. There is also a higher risk of boiler damage if the boiler (or other heat source) is kept alight, so make sure to switch off electric immersion heaters etc.

What can cause a burst pipe?

When water freezes it expands and puts pressure on whatever is containing it. In this case, frozen water may cause the pipes to split or crack.

Can pipes freeze and not burst?

They can. Frozen pipes do not always burst, particularly if the expanding ice can push water out through an open tap. However, pipes freeze rapidly so the time between freezing and bursting can be very short.

What happens when a pipe bursts?

A burst pipe means the structural integrity of the pipe is lacking. Therefore, when the ice in the pipes thaws it is likely to leak through the cracks or splits.

What are the signs of a burst pipe?

The main sign of a burst pipes are puddles or damp patches. Small puddles could simply be a leak, whereas large pools of water in multiple areas usually indicates a burst pipe and possibly noisy from the pressure loss.

How serious is a burst pipe?

Leaks, puddles or flooding caused by burst pipes could lead to serious structural or electrical damage in your home. Unless they are remedied, leaks can also create breeding grounds for mould and mildew which can be a health risk.

Should I call a plumber if my pipes are frozen or burst?

Yes. In most cases you should consult with a professional plumber to tackle known burst or frozen pipes. Similarly, if you don't know where the frozen pipes are or you can't access the area but suspect that you may have frozen or burst pipes, it is best to call a plumber for assistance.

How do I find a good local plumber?

You can find a high quality heating and plumbing expert online via the Chartered Institute of Plumbing and Heating Engineering’s find a plumber or heating engineer tool.