When to worry about pipes freezing –telltale signs

How cold is too cold, and what are the key signs to look out for? We asked home maintenance professionals when frozen pipes should be a concern

three image hero with sinks and bath
(Image credit: Future PLC)

Winter can be a magical time, but the cold, harsh weather rolling in can cause some less-than-ideal scenarios at home. No one wants to wake up to no running water, or a leak caused by a burst pipe.

There are a number of ways to avoid burst pipes, and it's a good idea to know when frozen pipes might be a concern so you can be prepared. 

Take steps to winterize your home with the advice from home maintenance experts below.

When to worry about pipes freezing

When water freezes, it expands, and the pipes do not. Here are temperatures and telltale signs to look out for this winter to avoid a plumbing explosion.

frozen downpipe

(Image credit: Alamy)

1. Temperatures of below 32°F

If the water inside the pipes reaches 32°F or lower, then it will be at risk of freezing. Generally, it's advised to maintain an indoor temperature of 55°F to reduce the likelihood of this happening.

It needs to be colder than 32°F outside for the inside of the pipes to become that cold – Eric Vanasdale from insurance company Country Financial shares that some studies have shown it needs to be 20°F outside, but it’s better to be aware of the concern before it gets that cold. 

'Keep in mind that this doesn’t necessarily mean you can set your furnace at 33°F degrees and be safe. Exterior walls will be colder and cold air can get into the house through drafty windows and doors and around holes in walls for items like pipes and wires. You need to keep your house warmer to offset the colder exterior temperatures,' Eric explains.

Another rule of thumb to follow is that anytime the temperature of the air outside the home gets below freezing, then there is a possibility that the pipes in the home will freeze too. Josh Rudin disaster restoration professional from ASAP Restoration LLC recommends we monitor the temperature outside to determine when additional heating is needed to keep pipes from freezing and thus bursting at inopportune times.

Josh Rudin
Josh Rudin

In April of 2008 that Joshua realized he wanted to be the person that people trust for everything they need when disaster strikes their home or business. This is when ASAP Restoration LLC, was born. During the early days of ASAP Restoration LLC, Joshua was a one-man operation with a very full home garage filled with materials, supplies, and equipment. It wasn’t long after gaining a reputation for providing clients with only the best work and service that Joshua decided to expand operations beyond his home garage and into Tempe where the company still resides today. 

2. Visible signs on pipes

Josh Rudin from ASAP Restoration LLC says to look out for hairline fractures caused by frozen water. While this doesn’t qualify as a burst pipe, it will equally cause water damage if left unattended. Small leaks in the form of hairline cracks will also be the first place that a burst can occur the next time the pipe freezes.

Frosty or wet exposed pipes are another key sign to look out for, indicating cold water inside the pipes. If you notice frost on the outside of pipes, it's advised to take steps to protect outdoor faucets from freezing.

3. When on vacation

Frozen pipes often happen overnight and can also be an issue when a home is left empty for an extended length of time. Andy Kerr, founder of BOXT, comments, 'We are approaching the time of year when the temperatures drop and the festive season begins. This is a time when many may find themselves away visiting relatives or even chasing some winter sun. When you spend time away from home during the winter months it is always important to prepare your property, especially the pipes, as they can be susceptible to freezing when the weather is really cold, which can cause extensive damage.

'The aftermath of this is often expensive, and so implementing preventative measures before you head off on your holiday is vital.'

Andy Kerr recommends maintaining adequate heating while you are away. The best temperature to set thermostat when on winter vacation is at least 50°F, to keep the pipes warm. If you have a smart thermostat, you can control when the heating comes on from your phone, so you can adjust according to the temperature.

In rooms that are unheated, like cellars and basements, or where there are exposed pipes, insulating pipes is a good way to help prevent any freezing and cracking of the pipes. This is also known as pipe lagging, and can be done with either insulation sleeves or foam pipe wrap. You can find pipe lagging at Amazon or your local DIY store.

'If you plan to venture on holiday during colder times of the year it’s a good idea to turn off your mains stop tap and open up the lowest sink or bath tap to relieve the initial pressure on the pipework,' Andy Kerr suggests. 'Turn the bath or sink tap off and leave the stop tap off too, this will limit any issues with pipes freezing, cracking or unwanted leaks while you are away.'

If you are away for a long period of time, it’s worth asking a trusted neighbor or a friend who lives nearby to occasionally check in on your home, to ensure that the heating is on and functioning properly, Andy suggests. 'This is also a good way to check for any signs of a water leak so that actions can be taken in a timely manner if a pipe has burst.'

Letting your outdoor faucet drip can prevent freezing, too.

4. Telltale smells and sounds

Bubbling and whistling sounds when you use the sink or flush the toilet could be a sign of frozen water inside the pipes, so if you notice something unusual, don't ignore it just in case it causes an issue later down the line. The same goes for bad smells coming from the faucet or drain.

Simple steps to take

  • Wrap up pipes in cold areas 
  • Let a bit of water run from taps in chilly spots 
  • Open sink cabinets to let warm air reach pipes 
  • Keep your thermostat at 55°F or higher
  • Make sure basements or crawl spaces have good airflow


Can pipes freeze in one night?

'Water pipes with cold water in them experiencing freezing temperatures in the evening can absolutely freeze over and burst all in one evening,' says Josh Rudin from ASAP Restoration LLC. 'Many people think that the pipe has to freeze all the way through the whole line in order for a burst to occur, but in reality, a small section can freeze and cause major problems while the rest of the line still has liquid water in it.'

Pipes can freeze if the water is below freezing for six hours or more.

Running water is something we take for granted, so it pays to know the signs to look out for, especially given the drastic temperature changes that can occur over winter and into early spring. Other draft-proofing measures around the home can help to maintain a warmer ambient temperature, making your home feel more comfortable and reducing the risk of plumbing headaches.

Millie Hurst
Section Editor

Millie Hurst is a freelance lifestyle writer with over six years of experience in digital journalism. Having previously worked as Solved Section Editor at Homes & Gardens and Senior SEO Editor at News UK in London and New York, Millie has written for an array of homes brands including Livingetc and Real Homes and was formerly Senior Content Editor at Ideal Home. She has written and edited countless features on home organization, decluttering and interior design and always hopes to inspire readers with new ways to enjoy their homes. She lives in Sheffield, South Yorkshire, and loves to weave nature-inspired decor and nods to time spent in Italy into her own home.