How to thaw a frozen pipe safely, and stop pipes freezing (UK, Germany, US)
If a tap only trickles in freezing weather, a pipe has probably frozen. Turn off the stop valve, open the tap, and thaw the pipe slowly with a wrapped hot water bottle or warm towels. Never use a flame.
By Abu Bakar SaadatPublished 28 October 20262 min readPublisher: Saadat Rafiq
✓ Reviewed by Sonia Abu Bakar, MSc Botany · 28 October 2026
IllustrationAt a glance
- Sign
- A tap that only trickles, or gives nothing, in freezing weather
- UK and Germany
- Turn the water off first, then open the tap
- US (Red Cross)
- Keep the faucet open while you thaw
- Never
- An open flame or a blowtorch
- Advice from
- Thames Water, enercity and the American Red Cross, read 27-28 October 2026
- Checked
- October 2026
UK, Germany and the US side by side
| UK (Thames Water) | Germany (enercity) | US (American Red Cross) | |
|---|---|---|---|
| First | Turn off the stop valve, usually under the kitchen sink | Shut off the frozen line, if needed at the main valve | Keep the faucet open |
| Heat with | A wrapped hot water bottle or warm towels | Hot cloths, heating mats or hot water bottles | Heating pad, hair dryer, space heater or hot towels |
| Never | An open flame (enercity, Red Cross); the Red Cross also rules out blowtorches and kerosene or propane heaters | ||
| Call | A plumber if it leaks | Your water supplier if the meter is damaged | A licensed plumber if you can't find or thaw it |
Step 1: spot a frozen pipe
In freezing weather, a tap that only trickles or gives nothing at all usually means a pipe has frozen. Check pipes in the coldest places first, such as under a sink on an outside wall, in the loft or in the garage.
Step 2: turn off the stop valve
The stop valve is usually under the kitchen sink; turn it clockwise (Thames Water). enercity says to shut off the frozen line so water can't flood out when it thaws. See how to turn off your main water valve. In the US, the Red Cross instead says to keep the faucet open as you thaw.
Step 3: open the tap
An open tap lets water escape as the ice melts (Thames Water). Take any wrapping or lagging off the frozen section, and move nearby furniture and belongings out of the way.
Step 4: thaw it slowly
Use a wrapped hot water bottle or warm towels (Thames Water), or hot cloths and heating mats (enercity). Never use an open flame.
Step 5: check for leaks
Run a dry cloth along the pipe. If water keeps escaping, keep the water off and call a plumber. If it's dry, turn the water back on slowly (Thames Water, enercity).
Stop it happening again
- Insulate pipes in unheated spaces (Red Cross). enercity adds that insulation alone isn't enough in long frosts: keep cellar windows shut and set radiators in cold rooms to frost protection.
- Outside taps: drain and store hoses, and close the inside valve that feeds the outdoor tap (Red Cross).
- In a cold snap: open cabinet doors under sinks, let the cold tap drip, and keep the thermostat the same day and night. Don't set it below 55°F (about 13°C) when you're away (Red Cross).
Questions readers ask
Should I turn the water off or leave the tap running?
It depends where you are. Thames Water (UK) and enercity (Germany) say to shut off the water first so the thawed pipe can't flood your home, then open the tap. The American Red Cross says to keep the faucet open while you thaw the pipe.
Can I use a hair dryer on a frozen pipe?
The American Red Cross lists a hair dryer, a heating pad, a space heater or hot towels. Thames Water suggests a wrapped hot water bottle or warm towels. None of them allow an open flame.
How do I know if the pipe has burst?
Once it has thawed, run a dry cloth along the pipe. Thames Water says that if water keeps escaping, keep the water off and call a plumber.
What temperature should I leave the heating on when I go away?
The American Red Cross says no lower than 55°F (about 13°C).
Sources
We base our articles on the makers' official documentation.
