Frozen pipes in a Bristol cold snap

Bristol is mild by UK standards. Most winters bring only a few hard frosts, so lagging gets forgotten and pipes in cold corners are left bare. Then a proper cold snap arrives and the calls start. Bristol Water’s leakage manager said in its November 2025 advice that every winter it sees a high number of bursts on its network and on customers’ private pipes due to freezing conditions.

This guide covers how to spot a frozen pipe, how to thaw it safely, and where Bristol homes are most at risk.

Why frozen pipes split

Water expands by nearly 10% when it turns to ice, according to Bristol Water. That expansion can split a pipe or push a joint apart, even on new pipework. The ice itself often acts as a plug, so nothing leaks until it melts. That is why so many bursts appear the morning after a thaw, not during the freeze.

Signs a pipe has frozen

• a tap gives no water, or only a trickle, in freezing weather
• your neighbours still have water
• the toilet cistern does not refill
• the boiler shows a fault and the small plastic pipe outside is frozen solid (see our guide to a frozen condensate pipe)
• frost or ice on a visible pipe

Before you assume it is your pipe, check Bristol Water’s incidents page. If the whole street is off, it is a network problem.

How to thaw a frozen pipe safely

These steps follow Bristol Water’s own advice.

1. Turn off the water at the inside stop tap.
2. If the heating and water heaters are already on, leave them on. If they are off, do not switch them on to thaw the pipes, as this could cause damage.
3. Drain the cold system by flushing the toilet and opening the cold taps over sinks and baths.
4. Look along the pipe for any split or bulge.
5. If you find no damage, open all the taps and thaw the frozen section with a towel soaked in warm water, or a hot water bottle wrapped in a towel.
6. Once it has thawed, turn the taps off and slowly turn the stop tap back on.
7. Check the pipe again under pressure before you switch on water heating.

Never use a blowtorch, heat gun or any naked flame. Old lead and plastic pipes melt and copper joints can fail. Keep electric heaters well away from wet areas.

If you find a split, keep the stop tap off and call a plumber. Our burst pipe repair page explains what happens next.

Where Bristol homes freeze first

Weak spot	Common in	Why it freezes
Loft cold water tank and pipes	Interwar semis in Henleaze, Knowle, Kingswood	Unheated loft, especially after new loft insulation keeps house heat below
Pipes on the outside wall of a rear extension	Victorian terraces in Bedminster, Easton, Bishopston	Single skin walls, pipes run close to the cold face
Outside taps	Most houses	Short exposed pipe with nothing to warm it
Supply pipe under a shallow path	Older terraces with short front gardens	Old pipes often laid shallower than modern ones
Pipes in garages and utility rooms	1980s and 90s homes in Bradley Stoke	Unheated spaces with washing machine feeds
Boiler condensate pipe	Combi boilers with an outside run	Thin plastic pipe carrying slow drips

Hillside homes catch more wind. In places like Totterdown and Knowle, exposed pipes on the back of steep terraces can freeze sooner than the same pipe in a sheltered street.

Bristol Water also notes that ground frost can move underground pipes and cause leaks on your supply pipe. You might see water in the garden, lower pressure, or no water at all.

How to prepare before the next cold snap

Bristol Water’s checklist is a good start:

• lag pipes and water tanks in lofts, garages and gardens
• find your inside stop tap and make sure it turns
• leave the heating on low if you go away
• get the boiler serviced
• bleed radiators
• keep a plumber’s details to hand

We would add:

• turn off and drain outside taps, using the isolating valve inside if there is one
• leave the loft hatch open a little in a deep freeze so some warm air reaches the tank
• check the lagging on pipes in rear extensions and under sinks on outside walls
• in a basement or lower ground flat, check pipes in vaults and under steps

Flats and empty homes

Bristol has a lot of empty rooms in winter. Student lets in Bishopston, Redland and Cotham often sit empty over Christmas, and holiday lets in Clifton can stand unused for days. An empty home with the heating off is the most likely to freeze. If you are a landlord, ask tenants to leave the heating on low over the break, or set a frost setting on the thermostat. Show them where the inside stop tap is before they leave. If you own a flat in a converted house, a burst in your empty flat can flood the flat below, so the same care helps your neighbours too.

Who pays if a frozen pipe bursts

Pipes inside your home and the supply pipe from the boundary are your responsibility, as Ofwat explains. Water damage is often covered by home insurance under escape of water. Our guide to burst pipe insurance claims covers what to record before the repair.