How do I thaw a frozen pipe safely?
Keep the faucet open, then warm the frozen section with an electric hair dryer, an electric heating pad, a space heater kept away from anything flammable, or towels soaked in hot water. Never use a blowtorch or any open flame. Keep applying heat until full water pressure returns, and call a licensed plumber if you cannot find or reach the frozen section. These steps follow American Red Cross guidance.
Find the frozen section
If a faucet gives only a trickle in cold weather, suspect a frozen pipe. The likely spots are against exterior walls and where the water service enters the house through the foundation.
Check the other faucets too. If one pipe froze, others may have.
Thaw it
Leave the faucet open. As the ice melts, water starts to flow, and running water helps melt the rest.
Apply gentle heat to the pipe: a hair dryer, an electric heating pad wrapped around it, a portable space heater, or hot wet towels. Do not use a blowtorch, a kerosene or propane heater, a charcoal stove, or any other open flame.
Watch for a leak as it thaws
A pipe that split while frozen often does not leak until the ice melts. Know where your main shutoff is before you start, and look along the pipe once water is flowing.
This is where a leak sensor on the floor under the vulnerable run earns its keep: the freeze alert tells you about the cold, and the leak alert tells you about the thaw.
Frequently asked questions
Will a frozen pipe thaw on its own?
Eventually, once the space warms up, but waiting leaves pressure in the line and you may not be there when a split pipe starts leaking. Thawing it deliberately with the faucet open is safer.
Does a frozen pipe always burst?
No. Many frozen pipes thaw without damage. The risk comes from pressure trapped between the ice and a closed faucet, which is why the faucet should stay open.
Related
- Freeze then thaw flood playbook
- Where should water leak sensors be placed?
- Should I let faucets drip to prevent frozen pipes?
Sources
Get a freeze alert for your space
ProbeHarbor watches probes in garages, crawlspaces, and cabins and alerts you before pipes freeze. The free plan includes email alerts; bring an ESP32 probe or connect Home Assistant.