How to Stop Pipes Freezing: What to Do and When

Prevent frozen pipes with simple UK winter precautions, and know exactly what to do if a pipe freezes, bursts or thaws and floods your home.

A frozen pipe is an inconvenience. A burst pipe is a flood. The pipe does not usually split while it is frozen; the damage shows when it thaws and water pours out through the crack. That is why the most expensive frozen pipe incidents often happen when the weather warms up, or when you return from a trip. A few cheap precautions greatly reduce the risk.

Where pipes freeze first

Water freezes in places the heating does not reach. Check these areas:

  • The loft: pipes and cold water tanks
  • Garages, outhouses and utility rooms
  • Under floors and in unheated cellars
  • External taps and outdoor pipework
  • The condensate pipe from a condensing boiler, which can freeze and make the boiler shut down

Prevention before the cold arrives

  1. Lag pipes and tanks. Foam pipe insulation costs a few pounds per length and is easy to fit with scissors and tape. Cover elbows and bends as well.
  2. Fix dripping taps and overflows. A trickle freezes faster than still water.
  3. Know your stop tap. Make sure it is accessible and turns smoothly. It is commonly under the kitchen sink, but may be in a cupboard or by the front door.
  4. Insulate outside taps. Use an insulating cover and turn off and drain any isolation valve.
  5. Do not insulate under the tank. In a loft, keep insulation away from underneath the cold water tank so a little heat from the house gets up there. Insulate above and around it.
  6. Set a frost setting. Many thermostats have a frost protection mode. If not, a low temperature setting of around 5 to 10 degrees Celsius is typically enough for a home that will be empty.

During a cold snap

  • Keep the heating on, even at a lower temperature, rather than switching it off altogether.
  • Open internal doors so warm air circulates.
  • Open cupboard doors under sinks on exterior walls.
  • Leave the loft hatch open so some heat reaches the tank.
  • Do not let a home on a cold night go completely unheated.

If you suspect a pipe has frozen

Signs include no water from a tap, a gurgling sound, or frost on a visible pipe. Act quickly but calmly.

  1. Turn off the water at the stop tap. This limits damage if the pipe is already cracked.
  2. Open the affected tap so water can flow as the pipe thaws.
  3. Warm the pipe gently with a hot water bottle, heat pad or hairdryer on a low setting, working from the tap end towards the frozen section.
  4. Never use a blowtorch or other naked flame, and never pour boiling water onto a pipe.
  5. Once water flows, check along the pipe for leaks.

If a pipe bursts

  • Turn off the stop tap at once.
  • Switch off the electricity at the consumer unit if water is near sockets, light fittings or appliances. If you are unsure that it is safe to reach, call an electrician.
  • Open taps to drain the system, starting with the cold taps, then flush the toilets.
  • Collect water in buckets and move valuables away.
  • Take photos for insurance, then call a plumber. If you rent, tell your landlord or agent straight away.

The frozen condensate pipe

A common cause of boiler failure in cold weather is a frozen condensate pipe. The boiler may display a fault code and stop. Pouring warm (not boiling) water over the pipe where it exits the house often solves it. If you are not comfortable doing this, or the fault returns, a Gas Safe registered engineer can reroute or lag the pipe.

Insurance and cost

Escape of water is a common claim type, and the cost of drying out and repairing can be far higher than the plumbing fix itself. Check what your home insurance covers, including any conditions about heating or leaving a property unoccupied. Plumber call-out rates vary by region and time of day, and emergency work typically costs more than a planned job.

For more seasonal prep, see our winter checklist. If you need a plumber, search on Compito, compare ID-verified providers by postcode and send a request.

Frequently asked questions

How cold does it have to be for pipes to freeze?

Unprotected pipes in unheated spaces can freeze when temperatures stay below zero for several hours. Wind chill and poor insulation make it more likely.

Should I leave taps dripping overnight?

It can help in some cases, but it is not a substitute for insulation and keeping the heating on. A better approach is lagging, heat and a known stop tap.

Who pays if a pipe bursts in a rented home?

Landlords are generally responsible for the plumbing and installations, but check your tenancy agreement and your own contents insurance for belongings. Report it in writing immediately.

Browse local services