Frozen Pipe — What to Do and How to Prevent a Burst

Exposed pipe in unheated space

Pipes in lofts, garages, and outside walls that aren't insulated freeze in sustained cold weather. Most common in Norwich during cold snaps below -3°C.

Condensate pipe freeze (boilers)

The boiler condensate pipe runs outside and commonly freezes in cold weather, causing the boiler to lock out.

Practical checks and next steps

You can thaw a frozen pipe yourself using warm (not boiling) water or a hairdryer on its lowest setting. But turn off the stopcock FIRST — if the pipe has split, you need the water off before the ice melts.

• Turn off the main stopcock immediately — it's usually under the kitchen sink or where the supply enters.
• Open nearby taps to relieve pressure.
• Locate the frozen section — often where a pipe exits the building or passes through an unheated space.
• Apply warmth gently: warm water bottle, hairdryer on low, or warm cloths — never a naked flame.
• For a frozen boiler condensate pipe: pour lukewarm water along its length.
• Once thawed, turn water back on slowly and check for drips before fully restoring.
• If a pipe has burst, call a plumber immediately.